Scientific American Supplement, No. 288
by
Various
Part 1 out of 3
Olaf Voss, Don Kretz, Juliet Sutherland,
Charles Franks and the Online Distributed Proofreading Team.
[Illustration]
SCIENTIFIC AMERICAN SUPPLEMENT NO. 288
NEW YORK, JULY 9, 1881
Scientific American Supplement. Vol. XI, No. 288.
Scientific American established 1845
Scientific American Supplement, $5 a year.
Scientific American and Supplement, $7 a year.
* * * * *
TABLE OF CONTENTS.
I. ENGINEERING AND MECHANICS--Dry Air Refrigerating Machine.
5 figures. Plan, elevation, and diagrams of a new English
dry air refrigerator
Thomas' Improved Steam Wheel. 1 figure
The American Society of Civil Engineers. Address of President
Francis, at the Thirteenth Annual Convention, at Montreal. The
Water Power of the United States, and its Utilization
II. TECHNOLOGY AND CHEMISTRY.--Alcohol in Nature. Its presence
in earth, atmosphere, and water. 6 figures. Distillatory apparatus
and (magnified) iodoform crystals from snow water, from
rain water, from vegetable mould, etc.
Detection of Alcohol in Transparent Soaps. By H. JAY
On the Calorific Power of Fuel, and on Thompson's Calorimeter.
By J.W. THOMAS
Explosion as an Unknown Fire Hazard. A suggestive review of
the conditions of explosions, with curious examples
Carbon. Symbol C. Combining weight. 12. By T. A. POOLEY
Second article on elementary chemistry written for brewers
Manufacture of Soaps and their Production. By W. J. MENZIES
The Preparation of Perfume Pomades. 1 figure. "Ensoufflage"
apparatus for perfumes
Organic Matter in Sea Water
Bacteria Life. Influence of heat and various gases and chemical
compounds on bacteria life
On the Composition of Elephant's Milk. By Dr. CHAS. A. DOREMUS.
Comparison of elephant's milk with that of ten other mammals
The Chemical Composition of Rice. Maize, and Barley. By J. STEINER
Petroleum Oils. Character and properties of the various distillates
of crude petroleum. Fire risks attending the use of the
lighter petroleum oils
Composition of the Petroleum of the Caucasus. By P. SCHULZENBERGER
and N. TONINE
Notes on Cananga Oil. or Ilang-Ilang Oil. By F. A. FLUeCKIGER.
1 figure. Flower and leaf of Cananga odorata
Chian Turpentine, and the Tree which Produces It. By Dr.
STIEPOWICH. of Chios, Turkey
On the Change of Volume which Accompanies the Galvanic Deposition
of a Metal. By M. E. BOUTY
Analysis of the Rice Soils of Burmah. By R. ROMANIC, Chemical
Examiner, British Burmah
III. PHYSICS AND PHYSICAL APPARATUS.--Seyfferth's Pyrometer.
7 figures.--Pyrometer with electric indicator.--Method of
mounting by means of a cone on vacuum apparatus.--Mounting by
means of a sleeve.--Mounting by means of a thread on a tube.--
Mounting by means of a clasp in reservoirs.--The pyrometer
mounted on a bone-black furnace.--Mounted on a brick furnace
Delicate Scientific Instruments. By EDGAR L. LARKIN. An
interesting description of the more powerful and delicate
instruments of research used by modern scientists and their
marvelous results
The Future Development of Electrical Appliances. Lecture by
Prof. J. W. PERRY before the London Society of Arts.--Methods
and units of electrical measurements
Researches on the Radiant Matter of Crookes and the Mechanical
Theory of Electricity. By Dr. W. F. GINTL
Economy of the Electric Light. W. H. PREECE'S Experiments
Investigations
On the Space Protected by a Lightning Conductor. By WM. H.
PREECE.--5 figures
Photo-Electricity of Fluor Spar Crystals
The Aurora Borealis and Telegraph Cables
The Photographic Image: What It Is. By T. H. MORTON.
1 figure.--Section of sensitive plate after exposure and during
development
Gelatine Transparencies for the Lantern
An Integrating Machine. By C. V. BOYS.--1 figure
Upon a Modification of Wheatstone's Microphone and its
Applicability to Radiophonic Researches.
By ALEX. GRAHAM BELL,--2 figures
IV. ARCHITECTURE.--Suggestions in Architecture, 1 figure.--A
pair of English cottages. By A. CAWSTON
* * * * *
ALCOHOL IN NATURE--ITS PRESENCE IN THE EARTH, WATER, AND ATMOSPHERE.
A Chemist of merit, Mr. A. Muentz, who has already made himself known by
important labors and by analytical researches of great precision, has
been led to a very curious and totally unexpected discovery, on the
subject of which he has kindly given us information in detail, which we
place before our readers.[1] Mr. Muentz has discovered that arable soil,
waters of the ocean and streams, and the atmosphere contain traces of
alcohol; and that this compound, formed by the fermentation of organic
matters, is everywhere distributed throughout nature. We should add that
only infinitesimal quantities are involved--reaching only the proportion
of millionths--yet the fact, for all that, offers a no less powerful
interest. The method of analysis which has permitted the facts to be
shown is very elegant and scrupulously exact, and is worthy of being
made known.
[Footnote 1: The accompanying engravings have been made from drawings of
the apparatus in the laboratory of which Mr. Muentz is director, at the
Agronomic Institute.]
[Illustration: FIG. 1.--FIRST DISTILLATORY APPARATUS.]
[Illustration: FIG. 2.--SECOND DISTILLATORY APPARATUS.]
Mr. Muentz's method of procedure is as follows: He submits to
distillation three or four gallons of snow, rain, or sea water in an
apparatus such as shown in Fig. 1. The part which serves as a boiler,
and which holds the liquid to be distilled, is a milk-can, B. The vapors
given off through the action of the heat circulate through a leaden tube
some thirty-three feet in length, and then traverse a tube inclosed
within a refrigerating cylinder, T, which is kept constantly cold by a
current of water. They are finally condensed in a glass flask, R, which
forms the receiver. When 100 or 150 cubic centimeters of condensed
liquid (which contains all the alcohol) are collected in the receiver,
the operations are suspended. The liquid thus obtained is distilled anew
in a second apparatus, which is analogous to the preceding but much
smaller (Fig. 2). The liquid is heated in the flask, B, and its vapor,
after traversing a glass worm, is condensed in the tube, T. The
operation is suspended as soon as five or six cubic centimeters of the
condensed liquid have been collected in the test-tube, R. The latter is
now removed, and to its liquid contents, there is added a small quantity
of iodine and carbonate of soda. The mixture is slightly heated, and
soon there are seen forming, through precipitation, small crystals of
iodoform. Under such circumstances, iodoform could only have been formed
through the presence of an alcohol in the liquid. These analytical
operations are verified by Mr. Muentz as follows: He distills in the same
apparatus three to four gallons of chemically pure distilled water, and
ascertains positively that under these conditions iodine and carbonate
of soda give absolutely no reaction. Finally, to complete the
demonstration and to ascertain the approximate quantity of alcohol
contained in natural waters, he undertakes the double fractional
distillation of a certain quantity of pure water to which he has
previously added a one-millionth part of alcohol. Under these
circumstances the iodine and carbonate of soda give a precipitate of
iodoform exactly similar to that obtained by treating natural waters.
[Illustration: Fig. 3.--IODOFORM CRYSTALS OBTAINED DIRECTLY (greatly
magnified).]
[Illustration: FIG. 4,--IODOFORM CRYSTALS OBTAINED WITH RAIN WATER.]
In the case of arable soil, Mr. Muentz stirs up a weighed quantity of the
material to be analyzed in a certain proportion of water, distills it in
the smaller of the two apparatus, and detects the alcohol by means of
the same operation as before.
[Illustration: FIG. 5.--IODOFORM CRYSTALS OBTAINED WITH SNOW WATER.]
The formation of iodoform by precipitation under the action of iodine
and carbonate of soda is a very sensitive test for alcohol. Iodoform
has sharply defined characters which allow of its being very easily
distinguished. Its crystalline form, especially, is entirely typical,
its color is pale yellowish, and, when it is examined under the
microscope, it is seen to be in the form of six-pointed stars precisely
like the crystalline form of snow. Mr. Muentz has not been contented to
merely submit the iodoform precipitates obtained by him to microscopical
examination, but has preserved the aspect of his preparations by
means of micro-photography. The figures annexed show some of the most
characteristic of the proofs. Fig. 1 shows crystals of iodoform obtained
with pure water to which one-millionth part of alcohol had been added.
Fig. 2 exhibits the form of the crystals obtained with rain water; and
Fig. 3, those with water. Fig. 4 shows crystals obtained with arable
soil or garden mould. The first of Mr. Muentz's experiments were made
about four years ago; but since that time he has treated a great number
of rain and snow waters collected both at Paris and in the country. At
every distillation all the apparatus was cleansed by prolonged washing
in a current of steam; and, in order to confirm each analysis, a
corresponding experiment was made like the one before mentioned. More
than eighty trials gave results which were exactly identical. The
quantity of alcohol contained in rain, snow, and sea waters may be
estimated at from one to several millionths. Cold water and melted snow
seem to contain larger proportions of it than tepid waters. In the
waters of the Seine it is found in appreciable quantities, and in sewage
waters the proportions increase very perceptibly. Vegetable mould is
quite rich in it; indeed it is quite likely that alcohol in its natural
state has its origin in the soil through the fermentation of the organic
matters contained therein. It is afterward disseminated throughout the
atmosphere in the state of vapor and becomes combined with the aqueous
vapors whenever they become condensed. The results which we have just
recorded are, as far as known to us, absolutely new; they constitute a
work which is entirely original, which very happily goes to complete the
history of the composition of the soil and atmosphere, and which does
great credit to its author.--_La Nature_.
[Illustration: FIG. 6.--IODOFORM CRYSTALS OBTAINED WITH VEGETABLE
MOULD.]
* * * * *
DETECTION OF ALCOHOL IN TRANSPARENT SOAPS.
By H. JAY.
It appears that every article manufactured with the aid of alcohol is
required on its introduction into France to pay duty on the supposed
quantity of this reagent which has been used in its preparation. Certain
transparent soaps of German origin are now met with, made, as is
alleged, without alcohol, and the author proposes the following process
for verifying this statement by ascertaining--the presence or absence of
alcohol in the manufactured article: 50 grms. of soap are cut into
very small pieces and placed in a phial of 200 c.c. capacity; 30 grms.
sulphuric acid are then added, and the phial is stoppered and agitated
till the soap is entirely dissolved. The phial is then filled up with
water, and the fatty acids are allowed to collect and solidify. The
subnatant liquid is drawn off, neutralized, and distilled. The first 25
c.c. are collected, filtered, and mixed, according to the process of MM.
Riche and Bardy for the detection of alcohol in commercial methylenes,
with 1/2 c.c. sulphuric acid at 18 deg. B., then with the same volume of
permanganate (15 grms. per liter), and allowed to stand for one minute.
He then adds 8 drops of sodium hyposulphite at 33 deg. B., and 1 c.c. of a
solution of magenta, 1 decigrm. per liter. If any alcohol is present
there appears within five minutes a distinct violet tinge. The presence
of essential oils gives rise to a partial reduction of the permanganate
without affecting the conversion of alcohol into aldehyd.
* * * * *
ON THE CALORIFIC POWER OF FUEL, AND ON THOMPSON'S CALORIMETER.
By J.W. THOMAS, F.C.S., F.I.C.
A simple experiment, capable of yielding results which shall be at least
comparative, has long been sought after by large consumers of coal and
artificial fuel abroad in order to ascertain the relative calorific
power possessed by each description, as it is well known that the
proportion of mineral matter and the chemical composition of coal differ
widely. The determination of the ash in coal is not a highly scientific
operation; hence it is not surprising that foreign merchants should
have become alive to the importance of estimating its quantity. While,
however, the nature and quantity of the ash can be determined without
much difficulty, the determination of the chemical composition of
coal entails considerable labor and skill; hence a method giving the
calorific power of any fuel in an exact and reliable manner by a simple
experiment is a great desideratum. This will become more obvious when
one takes into consideration the many qualities and variable characters
of the coals yielded by the South Wales and North of England coal
fields. Bituminous coals--giving some 65 per cent, of coke--are
preferred for some manufacturing purposes and in some markets.
Bituminous steam coals, yielding 75 per cent, of coke, are highly prized
in others. Semi-bituminous steam coals, yielding 80 to 83 per cent, of
coke, are most highly valued, and find the readiest sale abroad; and
anthracite steam coal (dry coals), giving from 85 to 88 per cent, of
coke (using the term "coke" as equivalent to the non-volatile portion of
the coal) is also exported in considerable quantity. Now the estimation
of the ash of any of these varieties of coal would afford no evidence
as to the class to which that coal belongs, and there is no simple test
that will give the calorific power of a coal, and at the same time
indicate the degree of bituminous or anthracitic character which it
possesses.
In order to obtain such information it is necessary that the percentage
of coke be determined together with the sulphur, ash, and water, and
these form data which at once show the nature of a fuel and give some
indication of its value. To ascertain the quantity of the sulphur, ash,
and water with accuracy involves more skill and aptitude than can
be bestowed by the non-professional public; the consequence is that
experiments entailing less time and precision, like those devised by
Berthier and Thompson, have been tried more or less extensively.
In France and Italy, Berthier's method--slightly modified in some
instances--has been long used. It is as follows:
70 grammes of oxide of lead (litharge) and 10 grammes of oxychloride of
lead are employed to afford oxygen for the combustion of 1 gramme of
fuel in a crucible. From the weight of the button of lead, and taking
8,080 units as the equivalent of carbon, the total heat-units of the
fuel is calculated. This experiment is very imperfect and erroneous upon
scientific grounds, since the hydrogen of the fuel is scarcely taken
into account at all. In the first place, hydrogen consumes only one
quarter as much oxygen as carbon, and, furthermore, two-ninths only of
the heating power of hydrogen is used as the multiplying number,
viz., 8,080, while the value of hydrogen is 34,462. In other words,
one-eighteenth only of the available hydrogen present in the fuel is
shown in the result obtained. Apart from this my experience of the
working of Berthier's method has been by no means satisfactory. There
is considerable difficulty in obtaining pure litharge, and it is almost
impossible to procure a crucible which does not exert a reducing action
upon the lead oxide. Some twelve months ago I went out to Italy to test
a large number of cargoes of coal with Thompson's calorimeter, and since
then this apparatus has superseded Berthier's process, and is likely to
come into more general use. Like Berthier's method, Thompson's apparatus
is not without its disadvantages, and the purpose of this paper is to
set these forth, as well as to suggest a uniform method of working by
means of which the great and irreconcilable differences in the results
obtained by some chemists might be overcome. It has already been
observed that a coal rich in hydrogen shows a low heating power by
Berthier's method, and it will become evident on further reflection that
the higher the percentage of carbon the greater will be the indicated
calorific power. In fact a good sample of anthracite will give higher
results than any other class of coal by Berthier's process. With
Thompson's calorimeter the reverse is the case, as the whole of the
heating power of the hydrogen is taken into account. In short, with
careful working, the more bituminous a coal is the more certain is it
that its full heating power shall be exerted and recorded, so far as the
apparatus is capable of indicating it; for when the result obtained is
multiplied by the equivalent of the latent heat of steam the product is
always below the theoretical heat units calculated from the chemical
composition of the coal by the acid of Favre and Silbermann's figures
for carbon and hydrogen. On the other hand, when the heating power of
coal low in hydrogen is determined by Thompson's calorimeter, much
difficulty is experienced in burning the carbon completely; hence a low
result is obtained. From a large number of experiments I have found that
when a coal does not yield more than 86 per cent, of coke, it gives its
full comparative heating power, but it is very questionable if equal
results will be worked out if the coke exceeds the above amount although
I have met with coals giving 87 per cent. of coke which were perfectly
manageable, though in other cases the coal did not burn completely. It
will be noted that the non-volatile residue of anthracite is never as
low as 86 per cent., and this, together with the very dry steam coals
and bastard anthracite (found over a not inextensive tract of the South
Wales Coal field), form a series of coals, alike difficult to burn in
Thompson's calorimeter. Considerable experience has shown that in no
single instance was the true comparative heating power of anthracite
or bastard anthracite indicated. With a view to accelerate the perfect
combustion of these coals, sugar, starch, bitumen, and bituminous
coals--substances rich in hydrogen--were employed, mixed in varying
proportions with the anthracitic coal, but without the anticipated
effect. Coke was also treated in a like manner. Without enlarging
further upon these futile trials--all carefully and repeatedly
verified--the results of my experiments and experience show that for
coals of an anthracitic character, yielding more than 87 per cent. of
coke, or for coke itself, Thompson's calorimeter is not suited as an
indicator of their comparative calorific power, for the simple reason
that some of the carbon is so graphitic in its nature that it will not
burn perfectly when mixed with nitrate and chlorate of potash. A sample
of very pure anthracite used in the experiments referred to, gave 90.4
per cent. of non-volatile residue, and only 0.84 per cent. of ash. This
coal was not difficult to experiment with, as combustion started with
comparative ease and proceeded quite rapidly enough, but in every
instance a portion of the carbon was unconsumed, and consequently
instead of about 13 deg. of rise in temperature only 10 deg. were recorded.
Since the calorific power of a coal is determined by the number of
degrees Fahrenheit which a given quantity of water is raised in
temperature by a known weight of fuel, it follows that every care should
be taken that the experiment be performed under similar atmospheric
conditions. The oscillation of barometric pressure does not appear to
affect the working, but the temperature of the room in which the
work was done, and especially that of the water, are most important
considerations. It has been observed by some who have used this
apparatus--and I have frequently noticed it myself--that the lower the
temperature of the water is under which the fuel is burnt the higher is
the result found. This has been explained on the assumption that the
colder the water used, the greater is the difference between the
temperature of the room and that of the water; hence it would be
expedient that in all cases when such experiments are made the same
difference of temperature between the air in the room and the water
employed should always exist. For example, if the temperature of the
room were 70 deg., and the water at 60 deg., then the same coal would give a
like result with the water at 40 deg. and the room at 50 deg.. This has been
regarded as the more evident, because the gases passing through
the water escape under favorable conditions of working at the same
temperature as the water, and are perfectly deprived of any heat in
excess of that possessed by the water. Under these circumstances it
would seem only reasonable that this assumption should be correct. It
was, however, found after a large number of experiments upon the same
sample of coal that this was not the case. 30 grammes of coal which
raises the temperature of the water 13.4 deg., when the water at starting
was 60 deg. and the room at 70 deg., gives 13.7 deg. rise of temperature with the
water at 40 deg. and the room at 50 deg.. Conversely, when the water is at 70 deg.
and the room at 80 deg., a lower result is obtained. The explanation appears
to be this: The gas which escapes from the water was not in existence in
the gaseous form previous to the experiment, and the heat communicated
to the gas being a definite quantity it follows that the more the gas
is cooled the greater the proportion of chemical energy in the shape of
heat will be utilized and recorded as calorific power.
In order, therefore, to make the experiment more simple and workable
at all temperatures, a sample of coal was selected, which should be
perfectly manageable and readily consumed. Appended is an analysis of
the coal employed (from Ebbw Vale, Monmouthshire):
Composition per cent.
Carbon...............................88.33
Hydrogen............................. 5.08
Oxygen............................... 3.28
Nitrogen............................. 0.55
Sulphur.............................. 0.70
Ash.................................. 1.26
Water (moisture)..................... 0.80
-----
100.00
In the following experiments the standard temperature of the water was
taken as 60 deg. F., and as the coal gave 13.4 deg. of rise of temperature, 67 deg.
F. was selected as the standard room temperature. The reason for this
room temperature is obvious, for, whatever heating effect the higher
temperature of the room may have upon the water in the cylinder during
the time occupied by the first half of the experiment, would be
compensated for by the loss sustained during the second half of the
experiment, when the temperature of the water exceeded that of the room.
The mean of numerous trials gave 13.4 deg. F. rise of temperature, equal to
14.74 lb. of water per lb. of coal. When the water was at 50 deg. and
the room at 57 deg., the mean of several experiments gave 13.5 deg. rise of
temperature. When the water was 40 deg. at starting and the room at 47 deg.,
13.65 deg. was the average rise of temperature. Trials were made at
intermediate temperatures, and the results always showed that higher
figures were recorded when the water was coldest. With a view of getting
uniformity in the results it was thought well to make experiments, in
order to find out what temperature the room should be at, so that this
coal might give the same result with the water at 50 deg., 40 deg., or at
intermediate temperatures. Without going much into detail, it was found
that when the temperature of the room was at 40 deg. and that of the water
40 deg., and the experiment was rapidly and carefully performed, 13.4 deg. rise
of temperature was given; but this result could be obtained without
special effort when the room was 42 deg. and the water 40 deg. at starting. It
is evident that the cooling effect of the air in the room upon the water
cylinder is very appreciable when the water has reached 13 deg. above that
of the room. When the water was at 50 deg. and the room at 55 deg., the coal
gave 13.4 deg. rise with ease and certainty, and it would not be out of
place to remark here that with those coals which burn well in Thompson's
calorimeter, the results of several trials are remarkably uniform when
properly performed. With the water at 70 deg. and the room at 80 deg., a like
result was worked out. Experiments at intermediate temperatures were
also carried out (see table in sequel). It is true that the whole
difference of temperature we are dealing with in making these
corrections is only 0.25, but 0.2 in the result, when multiplied by 537
to bring it into calories, as is done by the authorities in Italy, makes
more than 100 heat units--a serious difference when 5d. per ton fine is
attached to every 100 calories lower than the number guaranteed.
Taking the latent heat of steam as 537 deg. C., and multiplying this number
by 14.74, the evaporative power of the coal used in these experiments,
its equivalent in calories is 7,915. From the analysis of this coal,
disregarding the nitrogen and deducting an equivalent of hydrogen
for the oxygen present, the _total heat units_ given by Favre and
Silbermann's figures for carbon (8,080) and hydrogen (34,462) will
be 8,746. It will be seen, therefore, that the calorific power, as
determined by Thompson's apparatus, gives a much lower result when
multiplied by 537 than the heat units calculated from the chemical
composition of the coal. When I used Thompson's apparatus in the
chemical laboratory at Turin to determine the evaporative power of
various cargoes of South Wales coal, it was agreed by mutual consent
that the temperature of the water at starting should be 39 deg. F. (the
temperature at which the _heat unit_ was determined). The temperature
of the room was about 60 deg., but this varied, as the weather was somewhat
severe and changeable. Under these conditions, with the water at 39 deg. and
room 60 deg., the coal which gives 14.74 lb. of water per lb. of coal,
will give as high as 15.88 lb. of water per lb. of coal. This result
multiplied by 537=8,496 calories, approaching much more nearly to the
theoretic value. This method of working is still practiced abroad, but
experience has shown that very widely differing results follow when
working in this manner, especially if the temperature of the room is
changeable, as it naturally is where ash determinations and other
chemical work is proceeding simultaneously. The time the experiment
lasts, taking the reading on a quickly rising thermometer and other
considerations, render the experiments anything but trustworthy when
0.2 of a degree makes a difference of more than 100 calories. In the
instructions supplied with Thompson's calorimeter nothing is said as to
the temperature of the room in which the experiment is performed, but
simply that the water shall be at 60 deg. F. If, with the water at 60 deg., a
room were at 50 deg., as it often is in winter, a good coal would give 14
lb. of water per lb. of coal as the evaporative power; but if in summer,
the room were at 75 deg. and the water at 60 deg., the same coal would give 15
lb. of water per lb. of coal. If further evidence were needed of the
effect of temperature consideration of the experiments already referred
to will show how necessary it is that some general rule shall be
adopted. Considerable stress is laid (in the instructions) upon the
quantity of oxygen mixture used being determined by rough experiments.
This I have found leads to erroneous conclusions unless a number of
experiments are tried in the calorimeter, as it often happens that the
quantity which appears to be best adapted is not that which yields a
trustworthy result. There are many samples of South Wales coal, 30
grains of which will require 10 parts of oxygen mixture in order to burn
completely, but since a little oxygen is lost in drying and grinding,
and few samples of chlorate are free from chloride, it is not safe to
use less than 11 parts of oxygen mixture, but this amount is sufficient
in _all_ cases, and never need be exceeded. I have made numerous
experiments with various coals (anthracite, steam, semi-bituminous, and
bituminous, including a specimen of the ten yard coal of Derbyshire),
and find that with 11 parts of chlorate and nitrate of potash, they are
all perfectly manageable and yield the best results. It is quite clear
that the excess of chlorate is decomposed in all instances, and the
latent heat of the oxygen evolved, but those coals which are best to
experiment with did not yield results that differed when the quantity of
oxygen mixture was reduced to nearly the limit required for combustion
of the coal. Under these circumstances, therefore, the constant use
of 11 parts of oxygen mixture--a suitable quantity for all coals
exported--would enable operators to obtain similar figures, and make the
test uniform in different hands.
The following is a brief outline of the method of procedure recommended:
Sample the coal until an average portion passes through a sieve having
64 meshes to the square inch. Take about 300 grains (20 grammes) of this
and run through a brass wire gauze having 4,600 meshes to the square
inch, taking care that the whole sample selected is thus treated. One
part of nitrate of potash and 3 parts of chlorate of potash (dry) are
separately ground in a mortar, and repeatedly sifted through another
wire gauze sieve, having 1,000 meshes to the square inch, in order that
the oxygen mixture shall _not_ be ground to an impalpable powder, as
this is very undesirable. It absorbs moisture rapidly, and interferes
with the regularity of the combustion when very fine. 330 grains of the
powder are weighed out (after drying), and intimately incorporated
with 30 grains of coal--better with a spatula than by rubbing in a
mortar--and then introduced into a copper cylinder (31/2 inches long by 3/4
inch wide, made from a copper tube), and pressed down in small portions
by a test-tube with such firmness as is required by the nature of the
coal, not tapped on the bottom, since the rougher portions of the oxygen
mixture rise to the surface. As the temperature of a room is almost
invariably much higher than the water supply, a little hot water is
added to that placed in the glass cylinder, until the difference of
temperature between the water and the room is about the mark indicated
in the following table:
Room at The water should be
80 deg. F. 70 deg. F.
72 64
67 60
60 54
55 50
50 46
42 40
Say, for example, the room was at 57 deg. and the water placed in the
cylinder was at 46 deg.: add a little hot water and stir with the
thermometer until it assumes 52 deg.. By the time the excess of water has
been removed with a pipette until it is exactly level with the mark, and
all is ready, the temperature will rise nearly 0.5 deg.. Let the thermometer
be immersed in the water at least three minutes before reading. The fuse
should be placed in the mixture, and everything at hand before reading
and removing the thermometer. After igniting the fuse and immersing the
copper cylinder in the water, the apparatus should be kept in the best
position for the gases to be evolved all around the cylinder, and the
rate of combustion noted. Some coals are very unmanageable without
practice, and samples of "patent fuel" are sometimes met with,
containing unreasonable proportions of pitch, which require some caution
in working and very close packing, inasmuch as small explosions occur
during which a little of the fuel escapes combustion.
In order that the experiment shall succeed well, experience has shown
that the nature of the fuse employed has much to do with it. Plaited
or woven wick is not adapted, and will fail absolutely with dry coals,
unless it is made very free burning. In this case not less than
three-quarters of an inch in length is necessary, and the weight of such
is very appreciable. I always use Oxford cotton, and thoroughly soak it
in a moderately strong solution of nitrate of potash. When dry it should
burn a little too fast. The cotton is rubbed between two pieces of cloth
until it burns just freely enough; then four cotton strands are taken,
twisted together, and cut into lengths of 3/4 inch and thoroughly dried.
Open out the fuse at the lower end when placing it in the mixture so as
to expose as much surface as possible in order to get a quick start, but
carefully avoid pressing the material, and use a wire to fill up close
to the fuse. A slow start often spoils the experiment, through the upper
end of the cylinder becoming nearly filled up with potassic chloride,
etc.
By paying attention to such details, and following the method
recommended, the apparatus yields very satisfactory results with
bituminous and semi-bituminous coals.--_Chemical News_.
* * * * *
EXPLOSION AS AN UNKNOWN FIRE HAZARD.
Words pass along with meanings which are simple conventionalities,
marking current opinions, knowledge, fancies, and misjudgments. They
attain to new accretions of import as knowledge advances or opinions
change, and they are applied now to one set of ideas, now to another.
Hence there is nothing truer than the saying, "definitions are never
complete." The term explosion in its original introduction denoted
the making of a _noise_; it grew to comprehend the idea of _force_
accompanied with violent outburst; it is advancing to a stage in which
it implies _combustion_ as associated with destruction, yet somewhat
distinct from the abstract idea of the resolution of any form of matter
into its elementary constituents. The term, however, as yet takes in the
idea of combustion as a decomposition in but a very limited degree,
and it may be said to be wavering at the line between expansion and
dissociation.
Strictly, in insurance, fire and explosion are different phenomena.
A policy insuring against fire-loss does not insure against loss by
explosion. It thereby enforces a distinction which exists, or did exist,
in the popular mind; and fire, in an insurance sense, as distinct from
explosion, was accurately defined by Justice McIlvaine, of the Supreme
Court of Ohio (1872), in the case of the Union Insurance Company vs.
Forte, i.e., an explosion was a remote cause of loss and not the
proximate cause, when the _fire_ was a burning of a gas jet which did
not destroy, though the explosion caused by the burning gas-jet did
destroy. Earlier than this decision, however (in 1852), Justice Cushing,
of the Supreme Court of Massachusetts, in Scripture _vs_. Lowell Mutual
Fire Insurance Company, somewhat anticipated later definition, and
pronounced for the liability of the underwriter where all damage by the
explosion involves the ignition and burning of the agent of explosion.
That is, for example, the insurer is liable for damage caused by an
explosion from gunpowder, but not for an explosion from steam. The
Massachusetts Judge did not conceive any distinction as to fire-loss
between the instantaneous burning of a barrel of gunpowder and the
slower burning of a barrel of sulphur, and insurance fire-loss is not to
be interpreted legally by thermo-dynamics nor thermo chemistry. While
the legal principles are as yet unsettled, the tenor of current
decisions may be summed up as follows: If explosion cause fire, and fire
cause loss, it is a loss by fire as _proximate_ cause; and if fire cause
explosion, and explosion cause loss, it is a loss by fire as _efficient_
cause. Smoke, an imperfect combustion, damages, in an insurance sense,
as well as flame, which is perfect combustion; and where there is
concurrence of expanding air with expanding combustion, the law settles
on the basis of a common account. It's all "heat as a mode of motion."
Explosions are the resultants of elemental gases, vaporization,
comminution, contact of different substances, as well as of the
specifically named explosives. With new processes in manufacture,
involving chemical and mechanical transformations, and other uses of
new substances and new uses of old substances, explosions increase. The
flour-dust of the miller, the starch-dust of the confectioner, increase
in fineness and quantity, and they explode; so does the hop-dust of
the brewer. In 1844, for the first time, Professors Faraday and Lyell,
employed by the British government, discovered that explosion in
bituminous coal mines was the quickening of the comparatively slow
burning of the "fire-damp" by the almost instantaneous combustion of the
fine coal-dust present in the mines. The flyings of the cotton mill
do not explode, but flame passes through them with a rapidity almost
instantaneous, yet not sufficient to exert the pressure which explodes;
the dust of the wood planer and sawer only as yet makes sudden puffs
without detonating force. Naphtha vapor and benzine vapor are getting
into all places. One of the latest introductions is naphtha extracting
oil from linseed, and then volatilized by steam superheated to 400 deg. F.
This combination reminds us, as to effectiveness, of the combination at
the recent Kansas City fire, when cans of gunpowder and barrels of coal
oil both went up together.
But it is the unsuspected causes of explosion which make the great
trouble, and prominent among these is conflagration as itself the
cause of explosion, and such explosion may develop gases which are
non-supporters of combustion as well as those which are inflammable.
You throw table salt down a blazing chimney to set free the
flame-suppressing hydrochloric acid, you discharge a loaded gun up a
blazing chimney to put out the fire by another agency; still the salt,
with certain combinations, may be explosive, a resinous vapor may be
combustive in a hydrochloric atmosphere, and gunpowder isn't harmless
when thrown upon a blaze--in fact, our common fire-extinguisher, water,
has its explosive incidences as liquid as well as vapor.
Gases explosive in association may be set free by the temperature of
a burning building and get together. In respect to the old conundrum,
"Will saltpetre explode?" Mr. A. A. Hayes, Prof. Silliman, and Dr.
Hare's views were, as to the explosions in the New York fire of 1845,
that in a closed building having niter in one part and shellac or other
resinous material in another, the gaseous oxygen generated from the
niter and the carbureted hydrogen from the resins mingling by degrees
would at length constitute an explosive mixture. A brief consideration
of specific explosives uniting may serve to illustrate this phase of the
subject.
Though the explosion of gunpowder is the result of a chemical change
whereby carbonic acid gas at high tension is evolved (due to the
saltpeter and the charcoal), the effect and rapidity of action are
greatly promoted by the addition of sulphur. On the contrary, dynamite,
now so important, and various similar explosives, are but mixtures of
nitro-glycerine with earthy substances, in order to diminish and make
more manageable the development of the rending force of the base. The
explosive power of any substance is the pressure it exerts on all parts
of the space containing it at the instant of explosion, and is measured
by comparing the heat disengaged with the volume of gas emitted, and
with the rapidity of chemical action. In the case of gunpowder, the
proper manipulation and division of the grains is important, because
favoring _rapid_ deflagration; but in a purely chemical explosion, each
separate molecule is an explosive, and the reaction passes from the
interior of one to the interior of another, suddenly driving the atoms
much further apart than their naturally infinitesimal vibrations.
Purely chemical explosives like nitro-glycerine, gun-cotton, the
picrites, and the fulminates, present a terrible danger from the unknown
mode of the new union of atoms, and reaction of the particles within
themselves, in spontaneous explosions happening in irregular manner.
Some curious circumstances attend the manufacture and use of
gun-cotton,[1] nitro-glycerine, and dynamite. Baron von Link, in his
system of the artillery use of gun-cotton, diminishes the danger of
sudden explosion by twisting the prepared cotton into cords or weaving
it into cloth, thereby securing a more uniform density. Mr. Abel's mode
of making gun-cotton, which explosive is now used more than any other by
the British government, includes drying the damp prepared cotton upon
hot plates, _freely open to the air_. If ignited by a flame, however, in
an unconfined place, gun-cotton only burns with a strong blaze, but
if _confined_ where the temperature reaches 340 deg. F., it explodes with
terrific violence. Somewhat similar is the action of nitro-glycerine and
dynamite, which simply _burn_ if ignited in the open air, while the same
substance will _explode_ through a very slight concussion or by the
application of the electric spark; a red-hot iron, also, if applied,
will explode them when a flame will not. With care, nitro-glycerine can
be kept many years without deterioration; and it has been heated in a
sand-bath to 80 deg. C. for a whole day without explosion or alteration. One
curious experiment is deserving of mention: If a broad-headed nail be
partly driven into pine wood, and then some pieces of dynamite placed on
the head of the nail, the latter may be struck hard blows with a wooden
mallet without exploding the dynamite _so long as the nail will continue
to enter the wood_.
[Footnote 1: The purest gun-cotton may be regarded as a _cellulose_,
in which three atoms of hydrogen are replaced by three molecules of
peroxide of nitrogen.]
Taking gunpowder as the unit, picrate of potash (picric acid and
potassium) has five times more force, gun-cotton seven and a half times,
and nitro-glycerine ten times more force. There are others still more
powerful, but less known and used, and some explosives are quite
uncontrollable and useless.
But the particular object of these remarks is to refer to articles of
merchandise non-explosive under general conditions, but so in particular
circumstances, as the two fire-extinguishers, water and salt, are
explosive under given conditions. The memorable fire which, in July,
1850, destroyed three hundred buildings in Philadelphia, upon Delaware
avenue, Water, Front, and Vine streets, was largely extended by
explosions of possibly concealed or unknown materials, the presence of
the generally recognized explosives being denied by the owners of the
properties.
"The germ of the first knowledge of an explosive was probably the
accidental discovery, ages ago, of the deflagrating property of the
natural saltpeter _when in contact with incandescent charcoal_."[1]
Although much manipulation is deemed necessary to form the close
mechanical mixture of the materials of gunpowder, it has never been
proved that such intimate previous union is necessary to precede the
chemical reaction causing explosion; indeed, some explosions in powder
works, before the mixture of the materials, or just at its commencement,
seem to point to the contrary. It is also certain that in the
manufacture of gunpowder the usual nitrate of potassium (saltpeter) can
be replaced by the nitrates of soda, baryta, and ammonia, also by the
chloride of potassium; charcoal by sawdust, tan, resin, and starch; and
though a substitute for sulphur is not easily found, the latter, or a
similar substance, is not an absolute necessity in the composition of
gunpowder.[2]
[Footnote 1: Encyclopaedia Britannica, new edition, viii, p. 806.]
[Footnote 2: _Vide_ Abel's Experiments in Gunpowder, as detailed in
Phil. Trans. Eoy. Soc, 1874.--_Vide_ also _Bull. Soc. d'Encouragement_,
Nov., 1880, p. 633, _Sur les Explosives_.]
The generally received theory of the chemical action which makes
gunpowder explosive is that it is due to the superior affinity of the
oxygen of the niter (KNO_3) for the carbon of the charcoal, and the
production of carbonic acid gas (CO_2) and carbonic oxide (CO) suddenly
and in great volume. The latter extinguishes flame as well as the
former, unless its own flammability is supported by the oxygen of the
atmosphere until the degree of oxygenation CO_2 is reached. Considering
that water (H_2O) is composed of two volumes of hydrogen and one of
oxygen, and that under an enormously high temperature and the excessive
affinity of oxygen gas for potassium or sodium (freed from nitrate
union), dissociation of the water may be possible, aided by its being in
the form of spray and steam, we would hesitate to deny that an explosive
union of suitable crude salts could occur during the burning of a
building containing them when water for extinguishment was put on. Any
one who has seen the brilliance with which potassium and sodium burn
upon water can easily imagine how such strong affinity of oxygen for
these substances might aid in severing its union in water in their
presence and under extraordinary heat. It might be safe so say that the
presence of water under very high temperature may be as aidful to form
an explosive among such salts as have been named, as sulphur is for the
rapid combustion of gunpowder.
In the review for August, 1862 (Saltpeter Deflagrations in Burning
Buildings and Vessels--Water as an Explosive Agency), it was shown that
Mr. Boyden's experiments in 1861-62 proved that explosions would occur
when water was put upon niter heated alone, and stronger explosion from
niter, drywood, and sulphur; also explosion when melted niter was poured
on water. The following points we reproduce for comparison: If common
salt be heated separately to a bright heat, and water _at_ 150 deg. F.
poured on it, an explosion will occur. Niter mixed with common salt,
placed upon burning charcoal, and water added, produce a stronger
explosion than salt alone. Heating caustic potash to a white heat, and
adding _warm or hot water_, produces explosion. At a Boston fire small
explosions were observed upon water touching culinary salt highly
heated. Anthracite coal and niter heated in a crucible exploded when
_sea water_ was poured on them.
The production of explosion by the putting of water on nitrate of
potassium and chloride of sodium arises from the union, at high
temperature, of the oxygen of the water with the potash and soda. Of the
three liberated gases, hydrogen only is inflammable, and the other two
suffocative of flame; but together the nitrogen and chlorine are not to
be undervalued, for chloride of nitrogen is ranked as the most terrible
and unmanageable of all explosives. Chlorine is a great water separator,
but in the present case its affinity for hydrogen would result in
hydrochloric acid, a fire extinguisher.
What happens in chemical experiment may be developed on a large scale in
burning grocery, drug, or drysalters' stores, when great quantities of
materials, such as just mentioned, including common salt, almost always
present, are heated most intensely, and then subjected to the action of
water in heavy dashes, or in form of spray or steam.
Picric acid, the nature of which we have several times previously
mentioned, and which explodes at 600 deg. F. (only 28 deg. above gunpowder), may
also be an element in such explosions during fires. Its salts form, in
combinations, various powerful explosives, much exceeding gunpowder
in force; and they have been used to a considerable extent in Europe.
Picric acid, now much employed by manufacturers and dyers for obtaining
a yellow color, is always kept in store largely by drysalters and
druggists, and generally by dyers, but in smaller quantity.
In a very destructive fire which occurred in Liverpool, Eng., in
October, 1874, involving the loss of several "fire-proof" stores,
repeated explosions of the vapor of turpentine rent ponderous brick
arched vaults, and exposed to the flames stocks of cotton, etc., in the
stories above. This conflagration was started by the carelessness of an
_employee_ in snuffing a tallow candle with his fingers and throwing the
burning snuff into the open bung-hole of a sample barrel of turpentine,
of which liquid there were many hundreds of barrels on storage in the
buildings. Turpentine vapor united with chlorine gas may not produce
explosion, but by spreading flames almost instantly throughout the
burning buildings, such burnings have practically equaled, if not
excelled, explosions, which may sometimes be fire-extinguishers. In such
cases detonation may be prevented by there being ample space to receive
the suddenly ignited vapor, lessening the tension of it, but carrying
the flames much more rapidly than otherwise to inflammable materials at
great distance.
If disastrous results have arisen from the vapor of turpentine as a fire
spreader in vaults without windows, it is possible that if a quantity of
hot water were suddenly converted into steam in closely confined spaces,
effects of pressure might be observed, less destructive perhaps, but
resembling those which other explosives might produce. If the immense
temperature attained in some conflagrations be considered--sufficient
to melt iron and vitrify brick--it is possible to conceive of water as
being instantly converted into steam. Even a very small quantity of
water thus expanded could produce most disastrous results. While such
formation of steam, if it happened, would certainly extinguish most
flames in direct contact, the general phenomena shown would be
explosive.
A curious circumstance occurred at the Broad street (N.Y.) fire in 1845,
previously mentioned. The fire extended through to Broadway, and almost
to Bowling Green. A shock like a dull explosion was heard, and by many
this was attributed to the effects of gunpowder and saltpeter. Several
firemen were, at the moment of the shock, on the roof of the burning
building, when the whole roof was suddenly raised and then let down
into the street, carrying the men with it uninjured. One of the firemen
described the sensation "as if the roof had been first _hoisted_ up
and then squashed down." _Query:_ Was this like the common lifting and
falling back of the loose lid of a tea-kettle containing boiling water?
Was it from steam--at a low pressure perhaps--seeking vent through the
roof in like manner to the raising of the kettle-lid? Without dilating
on this part of the subject, we mention it as a possible cause of minor
explosions--doubtless to become better known in future. It may even be
that explosions happening from steam acting in close spaces may have
been attributed to gunpowder, or to niter and other salts, separate, but
suddenly caused to combine in chemical reaction.--_American Exchange and
Review._
* * * * *
CARBON.--SYMBOL C.--COMBINING WEIGHT 12.
By T.A. POOLEY, B.Sc., F.C.S.
This element, which next deserves our attention, is one of great
importance and wide distribution; it occurs in nature in both the free
and the combined states, and the number of compounds which it forms with
other elements is very large. Unlike the previous elementary bodies we
have studied, carbon is only known to us in the solid form when
free, although many of its combinations are gaseous at the ordinary
temperature and pressure. Carbon is known to exist in several different
physical states, thus illustrating what chemists call _allotropism_,
which means that substances of identical chemical composition sometimes
possess altogether different outward and physical appearances. Thus the
three states in which pure carbon exists, viz., diamond, graphite, or
plumbago, and charcoal are as different as possible, and yet chemically
they are all exactly the same substance. The diamond is the purest
carbon, and occurs in the crystalline form known as a regular
octahedron; the diamond is one of the hardest substances known, and is
therefore, utilized for cutting glass; it has also a very high specific
gravity, namely, 3.5, which means that it is three and a half times
heavier than water, and it is far heavier than any of the other
allotropic modifications of carbon. Graphite or plumbago, the second
form in which carbon occurs, is widely distributed in nature, and the
finer qualities are known as black lead, although no lead enters into
their composition, as they are composed of carbon almost as pure as the
diamond; the specific gravity of graphite is only 2.3. Charcoal, the
third allotropic modification of carbon, is by far the most common, and
is formed by the natural or artificial disintegration of organic matters
by heat; we thus have formed wood charcoal, animal charcoal, lamp-black,
and coke, all produced by artificial means, and we may also class with
these coal, which is a natural product, and which contains from 85 to 95
per cent. of pure carbon.
Wood charcoal is made by heating wood in closed vessels or in large
masses, when all the hydrogen, oxygen, and nitrogen are expelled in
the gaseous state, and the carbon is left mixed with the mineral
constituents of the wood; this form of carbon is very porous and light,
and is used in a number of industrial processes.
Animal charcoal, as its name implies, is the carbonaceous residue left
on heating any animal matters in a retort; and contains, in addition to
the carbon, a large proportion of phosphates and other mineral salts,
which, however, can be extracted by dilute acids. Animal charcoal
possesses to a remarkable degree the property of removing color from
solutions of animal and vegetable substances, and it is used for this
purpose to a large extent by sugar refiners, who thus decolorize their
dark brown sirups; in the manufacture of glucose and saccharums for
brewers' use, the concentrated solutions have to be filtered through
layers of animal charcoal in order that the resulting product may be
freed from color. The decolorizing power of animal charcoal can be
easily tested by any brewer, by causing a little dark colored wort to
filter through a layer of this material; after passing through once or
twice, the color will entirely disappear, or at all events be greatly
reduced in intensity. Animal charcoal also absorbs gases with great
avidity, and on this account it is utilized as a powerful disinfectant,
for when once putrefactive gases are absorbed by it, they undergo a
gradual oxidation, and are rendered innocuous, in the same way animal
charcoal is a valuable agent for purifying water, for by filtering the
most impure water through a bed of animal charcoal nearly the whole of
the organic impurities will be completely removed.
Lamp-black is the name given to those varieties of carbon which are
deposited when hydrocarbons are burned with an insufficient supply of
oxygen; thus the smoke and soot emitted into our atmosphere from our
furnaces and fireplaces are composed of comparatively pure carbon.
Coal is an impure form of carbon derived from the gradual oxidation and
destruction of vegetable matters by natural causes; thus wood first
changes into a peaty substance, and subsequently into a body called
lignite, which again in its turn becomes converted into the different
varieties of coal; these changes, which have resulted in the
accumulation of vast beds of coal in the crust of the earth, have been
going on for ages. There are very many different kinds of coal; some are
rich in hydrogen, and are therefore well adapted for making illuminating
gas, while others, such as anthracite, are very rich in carbon,
and contain but little hydrogen; the last named variety of coal is
smokeless, and is therefore largely used for drying malt.
Carbon occurs in nature also in a combined state; limestone, chalk, and
marble contain 12 per cent. of this element. It is also present in the
atmosphere in the form of carbonic acid, and the same compound of carbon
is present in well and river waters, both in the free state and combined
with lime and magnesia. All animal and vegetable organisms contain a
large proportion of carbon as an essential constituent; albumen contains
about 53 per cent., alcohol contains 52 per cent., starch 44 per cent.,
cane sugar 42 per cent., and so on. The presence of carbon in the large
class of bodies known to chemists as carbohydrates, of which starch and
sugar are prominent examples, can be easily demonstrated. If a little
strong sulphuric acid be added to some powdered cane sugar in a glass,
the mass will soon begin to darken in color and swell up, and in the
course of a few minutes a mass of black porous carbon will separate,
which can be purified from the acid by repeated washings; the sugar is
composed of carbon, hydrogen, and oxygen, the two last-named elements
being present in the exact proportion necessary to form water; the
sulphuric acid having a strong affinity for water, removes the hydrogen
and oxygen, and the carbon is then left in a free state.
Carbon forms two compounds with oxygen--carbon monoxide, commonly called
carbonic oxide, and carbon dioxide, commonly called carbonic acid; and
the last-named, being of most importance, will be studied first.
_Carbon Dioxide, or Carbonic Acid, Symbol CO_2_.--Carbonic acid occurs,
as we have already stated, in large quantities in combination with lime
and magnesia, forming immense rock formations of limestone, chalk,
marble, dolomite, etc.; it also issues in a gaseous state from
volcanoes, and it is always present in small quantities in the
atmosphere; it is found dissolved in well and river waters, and it is a
product of the respiration of animals. Brewers also are well aware of
the existence of this body, for it is evolved in enormous quantities
during the alcoholic fermentation of saccharine fluids. When
carbonaceous substances are burnt the bulk of the carbon is converted
into carbonic acid, and thus our furnaces and fireplaces are continually
emitting enormous quantities of carbonic acid into the atmosphere. With
these different sources of supply it might reasonably be thought that
carbonic acid would be gradually accumulating in our atmosphere; the
breathing of animals, the eruption of volcanoes, the combustion of
fuel, and the fermentation of sugar, are ever going on, and to a
fast-increasing extent with the progress of civilization, and yet the
proportion of carbonic acid in our atmosphere is no greater now than it
was at the earliest time when exact chemical research determined its
presence and quantity. A counteracting influence is always at work;
nature has beautifully provided for this by causing plants to absorb
carbonic acid, holding some of the carbon, and allowing the oxygen to
escape again into the atmosphere to restore the equilibrium of purity.
This mutual evolution and absorption of carbonic acid is continually
going on; occasionally there may be either an excess or a deficiency in
a particular place, but fortunately any irregularity in this respect is
soon overcome, and the air retains its original composition, otherwise
animal life on the face of the globe would be doomed to gradual but sure
extinction.
Carbonic acid can be prepared for experimental purposes by causing
dilute hydrochloric acid to act upon fragments of marble placed in a
bottle with two necks, into one neck of which a funnel passing through a
cork is fixed, and into the other a bent tube for conveying the gas into
any suitable receiver. The evolution of carbonic acid by this method is
rapid, but easily regulated, and the gas may be purified by causing
it to pass through some water contained in another two-necked bottle,
similar to the generator. The chemical change involved in this
decomposition is expressed by the following equation:
CaCO_3 + 2HCl = CO_2 + H_2O + CaCl_2
Calcium Hydrochloric Carbonic Water. Calcium
Carbonate. Acid. Acid. Chloride.
By referring to the table of combining weights given in a previous
paper, it will be seen that 100 parts of calcium carbonate will yield 44
parts of carbonic acid. Instead of hydrochloric acid any other acid may
be used, and in the practical manufacture of carbonic acid for aerated
waters sulphuric acid is the one usually employed. Carbonic acid is
colorless and inodorous, but has a peculiar sharp taste; it is half as
heavy again as air, its exact specific gravity being 1529; one hundred
cubic inches weigh 47.26 grains. It is uninflammable, and does not
support combustion or animal respiration. Under a pressure of about 38
atmospheres, at a temperature of 32 deg. F., carbonic acid condenses into
a colorless liquid, which may also be frozen into a compact mass
resembling ice, or into a white powder like snow. Carbonic acid is
soluble in water, and at the ordinary pressure and temperature one
volume of water will hold in solution one volume of the gas; under
increased pressures, far larger quantities of the gas can be held in
solution, but this is rapidly evolved as soon as the excess of pressure
is removed. Upon this property the manufacture of aerated waters
depends. The presence of free carbonic acid can be easily detected by
causing the gas to pass over the surface of some clear lime-water. If
any be present a white film of carbonate of lime will at once be formed.
In testing carbonic acid in a state of combination, the gas must first
be liberated by acting upon the substance with a stronger acid, and
then applying the lime-water test. The presence of large quantities of
carbonic acid in a gaseous mixture can be readily detected by plunging
into the vessel a lighted taper, which will be immediately extinguished.
This ought always to be adopted in a brewery, where many fatal accidents
have happened through workmen going down into empty fermenting vats and
wells without first taking this precaution.
The presence of carbon in this colorless gas can be demonstrated by
causing some of it to pass over a piece of the metal potassium placed
in a hard glass tube, and heated to dull redness; the potassium then
eagerly combines with the oxygen, forming oxide of potassium, and the
carbon is liberated and can be separated in the form of a black powder
by washing the tube out with water.
_Carbon Monoxide, or Carbonic Oxide. Symbol CO._--This is formed when
carbon is burnt with an insufficient supply of oxygen, or when carbonic
acid gas is passed over some carbon heated to redness. This gas is
continually being formed in our furnaces and fire-places; at the lower
part of the furnace, where the air enters, the carbon is converted into
carbonic acid, which in its turn has to pass through some red-hot coals,
so that before reaching the surface it is again converted into carbonic
oxide; over the surface of the fire this carbonic oxide meets with a
fresh supply of oxygen, and is then again converted into carbonic acid.
The peculiar blue lambent flame often observed on the surface of our
open fire-places is due to the combustion of carbonic oxide, which has
been formed in the way we have just described. Carbonic oxide is a
colorless, tasteless gas, which differs from carbonic acid by being
combustible, and by not having any action on lime water.--_Brewers'
Guardian._
* * * * *
SEYFFERTH'S PYROMETER.
The thermometers and pyrometers usually employed are almost all based on
the expansion of some fluid or other, or upon that of different metals.
The first can only be constructed with glass tubes, thus rendering them
fragile. The second are often wanting in exactness, because of the
change that the molecules of a solid body undergo through heat, thus
preventing them from returning to exactly their first position on
cooling.
[Illustration: Fig. 1.--Pyrometer with Electric Indicator.]
The principle of the Seyfferth pyrometer is based on the fact that
the pressure of saturated vapors, that is, vapors which remain in
communication with the liquid which has produced them, preserves a
constant ratio with the temperature of such liquid, while, on the other
hand, the temperature of the latter when shut up in a vessel will
correspond exactly with that of the medium into which it is introduced.
[Illustration: Fig. 2.--Method of Mounting by means of a cone on vacuum
apparatus.]
[Illustration: Fig. 3.--Mounting by means of a sleeve on vacuum
apparatus.]
This instrument is composed of a metallic vessel or tube which contains
the liquid to be exposed to heat, and of a spring manometric apparatus
communicating with the tube, and by means of which the existing
temperature is shown. The dial may be provided with index needles to
show minimum and maximum temperatures, as well as be connected with
electric bells (Fig. 1) giving one or more signals at maximum and
minimum temperatures. The vessel to contain the liquid may be of any
form whatever, but it is usually made in the shape of a straight or
a bent tube. The nature of the metal of which the latter is made is
subordinate, not only to the maximum temperature to which the apparatus
are to be exposed, but also to the nature of the liquid employed. It is
of either yellow metal or iron. To prevent oxidation of the tube, when
iron is employed, it is inclosed within another iron tube and the space
between the two is filled in with lead. When the apparatus is exposed to
a high temperature the lead melts and prevents the air from reaching the
inner tube, so that no oxidation can take place.
_Pyrometers filled with Ether._-These are tubular, and constructed of
yellow metal, and are graduated from 35 deg. C. to 120 deg.. They are used for
obtaining temperatures in vacuum apparatus, cooking apparatus, diffusion
apparatus, saturators, etc. Figs. 2, 3, 4, and 5, show the different
modes of mounting the apparatus according to the purpose for which it is
designed.
_Pyrometers filled with distilled water_ are used for ascertaining
temperatures ranging from 100 deg. to 265 deg. C., 80 deg. to 210 deg. R., or 212 deg. to
510 deg. F.
_Pyrometers filled with mercury_ are constructed for ascertaining
temperatures from 360 deg. to 750 deg. C.
[Illustration: Fig. 4.--Mounting on horizontal pipes by thread on the
tube.]
[Illustration: Fig. 5.--Mounting by means of a clasp in reservoirs.]
APPLICATION OF THE PYROMETER IN BONE BLACK FURNACES.
The temperature necessary for the complete carbonization of the organic
substances of animal charcoal is from 430 deg. to 500 deg. C. In order to
transmit this temperature from the cylinder to the charcoal it is
indispensable that the air surrounding the cylinder be heated to 480 deg.
to 550 deg.. If the heating of the animal black exceeds 500 deg. the product
hardens, diminishes in volume, and loses its porosity. There are two
methods of ascertaining the temperature of the red-hot bone black by
means of the pyrometer: First, by inserting the tube of the instrument
into the black. (Fig. 6, a.) Second, by finding the temperature of the
hot gases in the furnaces (Fig. 6, b.). In the first case, the plunge
tube should be of sufficient length to allow its extremity to penetrate
to the very bottom layer of the red-hot black. This mode of direct
control of the temperature of the black is only employed for
ascertaining the work accomplished by the furnace, that is to say, the
ratio existing between the temperature of the hot air surrounding the
cylinder and the black itself. This calculation being effected, it is
useless to note the differences of temperature which arise in the spaces
between the cylinders of which the furnace is composed.
The position that the pyrometer should occupy is subordinate to the
construction of the furnace. Fig. 6 shows the type which is most
employed.
[Illustration: Fig. 6.--The Pyrometer mounted on a bone-black furnace.]
In a furnace with lateral fire-place, cc are the heating cylinders,
and dd the cooling cylinders. C D is the plate on which are mounted
vertically the former, and from which are suspended the latter, b shows
the pyrometer, the length of which must be such that the manometric
apparatus shall stand out one or two inches from the external surface of
the wall, while its tube, traversing the wall, shall reach the very last
row of heating cylinders.
That the apparatus may form a permanent regulator for the stoker it is
well to adapt to it an arrangement permitting of a graphic control of
the work accomplished and signaling by means of an electric bell when
the temperature of the gases in the furnace descends below 480 deg. C. or
rises above 550 deg. C.
APPLICATION OF THE APPARATUS TO BRICK FURNACES AND IN THE MANUFACTURE OF
CHEMICAL PRODUCTS.
The operation of heating brick furnaces is generally performed according
to empirical methods, the temperature having to vary much according to
the products that it is desired to obtain. It is necessary, however, for
a like product to maintain as uniform a temperature as possible. These
observations are particularly applicable to continuous furnaces such as
annular brick furnaces, etc., in which a uniformity of temperature in
the different chambers is of vital importance to perfect the baking. In
these furnaces the tube of the pyrometer is inserted through one of the
apertures at the top, as shown in Fig. 7. The dial is graduated up to
750 deg., which is more than sufficient, since the temperature of the upper
part of a compartment fully exposed to the heat rarely exceeds 670 deg. to
680 deg. C.
[Illustration: Fig. 7.--The Pyrometer mounted on a brick furnace.]
* * * * *
MANUFACTURERS' SOAPS AND THEIR PRODUCTION.
By W. J. MENZIES.
Potash soaps are generally superior to soda soaps for most purposes, but
more especially in washing wool and woolen goods. The difference between
the use of a potash and a soda soap for these purposes is very marked.
Potash lubricates the fiber of the wool, renders it soft and silky, and
to a certain extent bleaches it; soda, on the other hand, has a tendency
to turn wool a yellow color, and renders the fiber hard and brittle.
It cannot be too strongly insisted upon, therefore, that nothing but a
potash soap (or some form of potash in preference to soda if an alkali
alone is employed) should be used in washing wool in any form--either
manufactured or unmanufactured. This is fully borne out by nature,
who invariably assimilates the most appropriate substances. Wool when
growing in its natural state is lubricated and protected by a sticky
substance called "grease" or "suinte;" this consists to the extent of
nearly half its weight of carbonate of potash, hardly a trace of soda
being present. It is very evident, therefore, that potash must be more
suitable for washing wool than soda, as the teaching of nature is always
correct.
There are certain prejudices against the use of potash soap, which have,
to a great extent, prevented its more extensive use. Many consumers
of soap fancy that because a potash soap is soft it necessarily must
contain more water than a soda soap; this, however, is quite an
erroneous notion. A potash soap is soft, because it is the nature of all
potash soaps to be so, just in the same way that on the other hand all
soda soaps are hard. As an actual fact a good potash soap contains
less water than many quite hard soda soaps that are now in the market.
Another reason is that soapmakers have had every interest in using soda
in preference to potash--particularly when latterly soda has been so
cheap.
Potash not only is a more expensive alkali, but its combining equivalent
is greatly against it as compared with soda; that is to say, that
thirty-one parts of actual or anhydrous soda will saponify as much
tallow or oil as forty-seven parts of anhydrous potash. It will be
evident, therefore, that the use of potash instead of soda is decidedly
more advantageous to the soapboiler, and more particularly in the
present age, when the demand is for cheap articles, often quite without
regard to the quality or purpose for which they are to be used. As far
as consumers are concerned, this has been a mistake. Potash soap, though
it may cost more, is in most cases actually the most economical. Soap is
never used in exact chemical equivalents, but an excess is always
taken. Potash soap is much more soluble than a soda soap; it therefore
penetrates the fiber, and consequently removes dirt and grease much more
quickly. Notwithstanding, also, that its chemical combining equivalent
is greater than that of soda, it is, nevertheless, the strongest base,
and always combines with any substance in preference to soda. For these
reasons--probably combined also with the fact that in the whole realm of
the animal and vegetable kingdoms, to which all textile fabrics belong,
potash is more naturally assimilated than soda--a smaller quantity of
potash soap will do more practical work than a larger quantity of soda
soap.
There are other reasons why potash soaps have not been used; originally
soft soap was made either with fish oil or olive oil. Fish oil is
objectionable, as the strong smell imparted to the soap renders it unfit
for many finishing purposes. Nothing can be better than olive oil soap,
but it is a costly article, and only can be used for finer purposes.
There are now, however, many of the seed oils that are much cheaper.
Linseed, rape seed, and cotton seed all produce a good soap. Cotton seed
oil is particularly suitable for the purpose; the manufacture of this
oil during the last few years has been brought to great perfection, and
the cost is now much less than that of tallow or of any other seed oil.
It is now difficult to distinguish a well refined cotton seed oil from
olive oil; it is therefore in every way suitable for making soft soap.
One of the chief causes, however, why potash soap has not been
more generally made is that a convenient form of potash has been
unobtainable. For many years the only source of potash was from the
ashes of burnt trees. These ashes are collected, mixed with lime,
lixiviated, and the resulting lye boiled down. The result is a very
impure form of potash, also of a very variable composition, depending
upon the trees used for the purpose. Canada has been the principal
source of supply of this form of potash; hence the commercial name
of Montreal potashes. The classification of "firsts," "seconds," and
"thirds" is from the inspection at the warehouse there; this, however,
is exceedingly superficial, the ashes being simply tested for their
_alkaline_ strength, with no discrimination between potash and soda,
which is a difficult and delicate chemical test. Soda being now far
cheaper than potash, and also the alkaline equivalent, as previously
explained, being greatly in favor of soda, there has been every
inducement to "enterprising" producers of ashes to adulterate them with
soda, which, in many cases, has been largely done. Another source of
potash has been beetroot ashes, very similar to wood ashes, and also
German carbonate of potash, which latter about corresponds to a common
soda ash, as compared with caustic soda; with these articles, a tedious
boiling process, very similar to the old process for the production
of hard soap, had to be adopted, the ashes, or carbonate of potash,
previously being dissolved and causticized with lime by the soap maker.
The production of a first-class soft soap was also a very difficult
operation, as the impurities and soda contained varied considerably,
often causing the "boil" to go wrong and give considerable trouble to
the soapboiler.
During the last two years, however, caustic potash has been introduced,
that manufactured by the Greenbank Alkali Co., of St. Helens, being very
nearly pure. With this article there is no difficulty in producing a
pure potash soap, either for wool scouring, fulling, or sizing, by a
cold process very similar to that described for the production of hard
soda soap with pure powdered caustic soda.
The following directions will produce an excellent soap for wool
scouring: Fifty pounds of Greenbank pure caustic potash are put into
eight gallons of soft water; the potash dissolves immediately, heating
the water. This lye is allowed to cool, and then slowly added, with
continual mixing, to 20 gallons of cotton seed oil, mixed with 20 pounds
of melted tallow, the whole being brought to a temperature of about 90 deg.
F. After stirring for some minutes, so as to completely combine the lye
and oil, the mixture is left for two days in a warm place, when a slow
and gradual saponification of the mass takes place. If when examined the
oil and lye are then found not completely combined, the stiff soap is
again stirred and left two days, when the saponification will be found
complete, the result being the formation of about 330 pounds of very
stiff potash soap, each pound being equal to about two pounds of the
ordinary "fig" soap sold. The requisite quantity is thrown into the
scouring vat with about five per cent of its weight of refined pearl ash
to increase the alkali present, the weight depending somewhat upon the
kind of wool washed on purpose for which the soap is required. If the
wool is very dirty or greasy, rather a stronger soap is sometimes
advisable. This can easily be attained by reducing the quantity of oil
used to 18 gallons.
The advantages to be gained by the wool scourer or other consumer making
his own potash soap are that a pure, uniform article can always be thus
produced at a less cost than that at which the soap can be bought.
Potash soap, like soda soap now sold, is much adulterated, in addition
to all the impurities originally contained in the potash used, and
which, unlike soda soap, cannot be separated by any salting process.
Many other adulterations are added to increase the weight and cheapen
the cost. Silicate of potash, resin, and potato flour are all more or
less employed for this purpose, to the gain of the soap maker and at the
expense of the consumer.
The production of potash soap for fulling and sizing, and the most
suitable oils and tallow for the production of the various qualities
required for these purposes, must be reserved for the next
issue.--_Textile Manufacturer._
* * * * *
THE PREPARATION OF PERFUME POMADES.
We have, on a previous occasion, described the process of "maceration"
or "enfleurage," that is, the impregnation of purified fat with the
aroma of certain scented flowers which do not yield any essential oil in
paying quantities. At present we wish to describe an apparatus which
is used in several large establishments in Europe for obtaining such
products on the large scale and within as short a time as possible. The
drawing gives the idea of the general arrangement of the parts rather
than the actual appearance of a working apparatus, for the latter will
have to vary according to the conveniences and interior arrangements of
the factory.[1]
[Footnote 1: Our illustration has been taken from C. Hofmann,
"Chemisch-technisches Universal-Receptbuch," 8vo, Berlin, 1879, p. 207.]
A series of frames with wire-sieve bottoms are charged with a layer of
fat in form of fine curly threads, obtained by pressing or rubbing the
fat through a finely-perforated sieve. The frames are then placed one
on top of the other, and to make the connection between them air-tight,
pressed together in a screw press. A reservoir, E, is charged with a
suitable quantity of the flowers, etc., and tightly closed with the
cover, after which the bellows are set into motion by any power most
convenient. Scented air is thereby drawn from the reservoir, E, through
the pipe, G B, toward the stack of frames containing the finely divided
fat, which latter absorbs the aroma, while the nearly deodorized air is
sent back to the reservoir by the pipe, D, to be freshly charged and
again sent on its circuit. This apparatus is said to facilitate the
turning out of nearly twenty times the amount of pomade for the same
number of frames and the same time, as the old process of "enfleurage."
It might be called the "ensoufflage" process.--_New Remedies._
[Illustration: "ENSOUFFLAGE" APPARATUS FOR PERFUMES.]
* * * * *
ORGANIC MATTER IN SEA-WATER.
At a recent meeting of the London Chemical Society, Mr. W. Jago read
a paper "On the Organic Matter in Sea-water." On p. 133 of the "Sixth
Report of the Rivers Commission," it is stated that the proportion
of organic elements in sea-water varies between such wide limits in
different samples as to suggest that much of the organic matter consists
of living organisms, so minute and gelatinous as to pass readily through
the best filters. At the suggestion of Dr. Frankland, the author has
investigated this subject. The water was collected in mid-channel
between Newhaven and Dieppe by the engineers of the London, Brighton,
and South Coast Railway in stoppered glass carboys. The author has used
the combustion method, the albuminoid ammonia, and in some cases the
oxygen process of Prof. Tidy. To determine how the various methods of
water-analysis were effected by a change of the organic matter from
organic compounds in solution to organisms in suspension, some
experiments were made with hay-infusion. The results confirm those of
Kingzett (_Chem. Soc. Journ_., 1880, 15). the oxygen required first
rising and then diminishing. The author concludes that the organic
matter of sea-water is much more capable of resisting oxidizing agents
than that present in ordinary fresh waters, and that the organic matter
in sea-water is probably organized and alive.
* * * * *
BACTERIA LIFE.
W. M. Hamlet, in a paper before the London Chemical Society, said:
Flasks similar to those of Pasteur ("Etudes sur la Biere," p. 81),
holding about 1/4 liter, were used. The liquids employed were Pasteur's
fluid with sugar, beef-tea, hay infusion, urine, brewers' wort, and
extract of meat. Each flask was about half filled, and boiled for ten
minutes, whereby all previously existing life was destroyed. The flask
was then allowed to cool, the entering air being filtered through a plug
of glass wool or asbestos. The flask was then inoculated with a small
quantity of previously cultivated hay solution or Pasteur's fluid.
Hydrogen, oxygen, carbonic oxide, marsh-gas, nitrogen, and sulphureted
hydrogen, were without effect on the bacteria. Chlorine and hydric
peroxide (about 7 per cent, of a 5 vol. solution) were fatal to
bacteria. The action of various salts and organic acids in 5 per cent,
solution was tried. Many, including potash, soda, potassic bisulphite,
sodic hyposulphite, potassic chlorate, potassic permanganate, oxalic
acid, acetic acid, glycerin, laudanum, and alcohol, were without effect
on the bacterial life. Others--the alums, ferrous sulphate, ferric
chloride, magnesic and aluminic chlorides, bleaching powder, camphor,
salicylic acid, chloroform, creosote, and carbolic acid--decidedly
arrested the development of bacteria. The author has made a more
extended examination of the action of chloroform, especially as regards
the statement of Muentz, that bacteria cannot exist in the presence of
21/2 per cent, of chloroform, which substance is therefore useful in
distinguishing physiological from chemical ferments. The author
concludes that amounts of chloroform, phenol, and creosote, varying from
1/4 to 3 per cent., do not destroy bacteria, although their functional
activity is decidedly arrested while in contact with these reagents. To
use the author's words, bacteria may be pickled in creosote and carbolic
acid without being deprived of their vitality. The author concludes that
the substances which destroy bacteria are those which are capable of
exerting an immediate and powerful oxidizing action, and that it is
active oxygen, whether from the action of chlorine, ozone, or peroxide
of hydrogen, which must be regarded as the greatest known enemy to
bacteria.
Mr. Hamlet, in replying to some remarks of Messrs. Kingzett and
Williams, said that in all cases the solution which he had used had
been completely sterilized by exposure to a temperature of 105 deg. for ten
minutes. The India-rubber tubing he had used was steamed. Carbolic acid
solution must contain at least 5 per cent, of carbolic acid to be fatal
to bacteria. He was quite aware of the importance of distinguishing
between the action of the substances on various kinds of bacteria, and
was quite prepared to admit that a treatment which would be fatal to one
kind of bacterium might not injure another.
* * * * *
ON THE COMPOSITION OF ELEPHANTS' MILK.
[Footnote: Read before the American Chemical Society, June 3,1881.]
By CHAS. A. DOREMUS, M.D., Ph.D.
Noticing the recent advertisements in the city regarding the "Baby
Elephant," it occurred to me that perhaps no analysis of the milk
of this species of the mammalia had been recorded. This I found
corroborated, for though the milk of many animals had been subjected to
analysis, no opportunity had ever presented itself to obtain elephants'
milk.
Through the courtesy of Jas. A. Bailey I was enabled to procure samples
of the milk on several occasions.
On March 10, 1880, the elephant Hebe gave birth to the female calf
America. Hebe is now twenty eight years old, and the father of the calf,
Mandrie, thirty-two. Since the birth of the "Baby," the mother has been
in excellent health, except during about ten days, when she suffered
from a slight indisposition, which soon left her.
When born the calf weighed 2131/2 lbs., and in April, 1881, weighed 900
lbs. A very fair year's growth on a milk diet. At the time I procured
the samples both mother and calf were in fine health.
To obtain the milk was a matter of some difficulty. The calf was
constantly sucking, nursing two or three times an hour, morning, noon,
and night. The milk could be drawn from either of the two teats, but
only in small quantity. The mother gave the fluid freely enough,
apparently, to her infant, but sparingly to inquisitive man, so the ruse
had to be resorted to of milking one teat while the calf was at the
other.
When I first examined the specimens they seemed watery, but to my
surprise, on allowing the milk to stand, I could not help wondering at
the large percentage of cream.
The following represents approximately the daily diet of the mother:
Three pecks of oats, one bucket bran mash, five or six loaves of bread,
half a bushel of roots (potatoes, etc.), fifty to seventy-five pounds of
hay, and forty gallons of water.
Elephants eat continually, little at a time, to be sure, but are
constantly picking. This habit is also observable in the way the calf
nurses. The first specimen of milk was procured on the morning of April
5, the second on the 9th, and the third on the 10th.
The last exceeded the others in quantity, and is therefore the fairest
of the three. It took several milkings to get even these, for the calf
would begin to nurse, then stop, and when she stopped the flow of milk
did also.
I was assured by Mr. Cross and the keeper, Mr. Copeland, that the milk
I obtained had all the appearances of that drawn at various times since
the birth of the calf. Mr. Cross, when in Boston, compared the milk with
that from an Alderney cow, and found the volume of cream greater.
I endeavored to have the calf kept away from the mother for some hours,
but could not, since she is allowed her freedom, as she worries under
restraint, and besides, has never been taken from the mother. The calf
picked at oats and hay, but was dependent on the mother for nourishment.
It would have been a matter of great satisfaction to me had I been able
to obtain a larger quantity of the milk, or to have gained even an
approximate knowledge of the daily yield, but was obliged to content
myself with what I could get. By comparing several samples, however, a
just conclusion regarding the quality was found. The analyses of the
samples gave the following results:
No. I. II. III.
April 5, April 9, April 10,
Morning. Noon. Morning.
Quantity, 19 cc. 36 cc. 72 cc.
Cream, 52-4, vol.% 58 62
Reaction, Neutral. Slightly alkaline. Slightly acid.
Sp.gr., ---- ---- 1023.7
In 100 parts by weight.
Water............67.567 69.286 66.697
Solids...........32.433 30.714 33.303
Fat..............17.546 19.095 22.070
Solids not fat...14.887 11.619 11.233
Casein...........14.236 3.694 3.212
Sugar............14.236 7.267 7.392
Ash.............. 0.651 0.658 0.629
Ten grammes were taken for analysis, and in No. III. duplicates were
made.
It is evident from these analyses that the milk approaches the
composition of cream, yet it did not have the consistency of ordinary
cream--as cream even rose upon it. Under the microscope the globules
presented a very perfect outline, and were beautifully even in size and
very transparent.
The cream rose quickly, leaving a layer of bluish tinge below. The milk
was pleasant in flavor and odor, and very superior in these respects to
that of many animals such as goats or camels, and in quality equal to
that of cows. Nor did the milk emit any rank odor on heating.
When ten grammes were evaporated to dryness, the last portions of water
were hard to remove, as the residue fairly floated with oil. Only by
long-continued application of heat, and in analysis III. over sulphuric
acid in vacuo, could a constant weight be obtained.
I would have used sand in the drying, or Baumhauer's method of fat
extraction, but for the small quantity of milk at my disposal and from
fear of loss of fat in the latter case.
The fat in III. was determined by extracting the dried residue and also
with 20 c. c. of milk by adding alkali and shaking with ether, removing
and evaporating the ether and weighing the fat.
As is shown in the table the sp. gr. is very low, though the solids and
solids not fat are great. The ash, casein, and sugar are in about the
usual proportion. The weight of casein, it is true, is but half that of
the sugar. The milk indeed shows an unusually great preponderance of the
non-nitrogenized elements, and this seems to correspond with the wants
of the animal, since fatty tissues are greatly developed in elephants.
According to Mr. Cross, who has had large experience with these animals,
they are fatter in the wild state than in bondage. These specimens must
appear as exceptional; they may be considered by some as "strippings;"
but as against such a view we have the recurrence in each sample of
the same characteristics in the milk and a near correspondence in the
composition. As may be seen from the subjoined analyses, given by v.
Gorup Besanez,[1] the milk belongs to the class of which woman's and
mare's milk are members, especially as regards the proportion of the
non-nitrogenized to the nitrogenized elements.
[Footnote 1: "Lehrhuch der Physiologischen Chemie," pp. 423 and 424.]
Constituents. Woman. Cow. Goat. Ewe. Ass. Mare.
Water. 86.271 84.28 86.85 83.30 89.01 90.45
Solids. 13.729 15.72 13.52 16.60 10.99 9.55
Fat. 5.370 5.47 4.34 6.05 1.85 1.31
Casein. \ 3.57 2.53 \ \ \
2.950 5.73 3.57 2.53
Albumen. / 0.78 1.26 / / /
Milk Sugar. 5.136 4.34 3.78 3.96 \ 5.42
5.05
Ash. 0.223 0.63 0.65 0.68 / 0.29
Constituents. Buffalo. Camel. Sow. Hippo- Elephant.
potamus.
Water. 80.640 86.34 81.80 90.43 66.697
Solids. 19.360 13.66 18.20 9.57 33.308
Fat. 8.450 2.90 6.00 4.51 22.070
Casein. \ \ \ 4.40 \
4.247 3.67 5.30 3.212
Albumen. / / / /
Milk Sugar. 4.518 5.78 6.07 [1] 7.392
Ash. 0.845 0.66 0.83 0.11 0.629
[Footnote 1: Milk Sugar included.]
It may be remarked that though approaching the composition of cream it
still differs enough to require it to be considered milk.
Perhaps if a larger quantity of the milk could be collected, it would
have a more watery character, and approximate more nearly to other milks
in that respect. However this may be the quality of the fat deserves
some attention.
The fat has a light yellow color, resembling olive oil, is very pleasant
in odor and taste, is liquid at common temperatures, but solidifies at
18 deg. C. or 64 deg. F.
The cow must yield a considerable quantity of milk, since the growth of
the calf has been constant, and at the time these samples were milked
the mother gave as freely to her babe as she ever had since its birth.
The calf having gained seven to eight hundred pounds on a milk diet in
one year, it is presumable that it had no lack of nourishment.
In size the "Baby" compared equally with other elephants in the same
menagerie, who were known to be four and five years old.
From whatever standpoint, therefore, we view the lacteal product of
these four-footed giants, we are fully warranted in ascribing to it not
only extreme richness, but also great delicacy of flavor.
* * * * *
THE CHEMICAL COMPOSITION OF RICE, MAIZE, AND BARLEY.
By J. STEINER, F.C.S.
Rice contains much more starch, but on the other hand, much less
albuminous matter and ash, than maize and barley. The compositions of
different kinds of dried rice do not vary very much, but as the amount
of moisture in the raw grain ranges from 5 to 15 per cent., no brewer
ought to buy rice without having first of all inquired with the
assistance of a chemist as to the percentage of water present in the
sample.
Another point requiring attention is that of taking notice of the
acidity, which also varies a good deal for different sorts of rice. In
comparing the nutritive values of the three kinds of grain before us,
Pillitz obtained the following numbers:
Barley. Maize. Rice.
-------------- ------------- ------------------
Air Dried at Air Dried at Air Dried at With
Dry. 100 deg. C. Dry. 100 deg. C. Dry. 100 deg. C. Husk.
Moisture. 13.88 --- 13.89 --- 12.51 --- 12.00
Starch. 54.07 62.65 62.69 73.27 74.88 85.41 74.50
Dextrin and
sugar. 5.66 6.67 3.57 4.14 1.12 1.26 ---
Total albumen
matter. 14.00 16.28 10.63 12.35 9.19 10.40 7.80
Mineral matter. 2.33 2.70 1.48 1.71 0.84 0.94 2.30
Fatty matter. 2.30 2.68 4.36 5.03 0.78 0.88 0.30
Cellulose
matter. 7.76 9.02 3.38 4.50 0.68 1.11 3.10
-----------------------------------------------------------
100.00 100.00 100.00 100.00 100.00 100.00 100.00
On looking over this table, we notice that rice contains by about 20 per
cent, more starch than barley, and by about 10 to 12 per cent, more than
maize.
But on the other hand, barley and maize are richer in albuminous matter
and in ash. The extractive matter, _i. e._, the part which is soluble in
cold water, is also much greater in barley and maize than in rice. The
extractive matter is for barley 8.7 per cent., for maize 6.3 per cent.,
while rice contains only 2.1 per cent., and it consists in each case of
dextrin, sugar, the soluble part of the ash, and of some nitrogenous
matter (soluble albumen).
The amount of woody fiber or cellulose is considerable for rice with its
husk, but only slight for samples without husk. The seat of the mineral
matter of the grain of rice is mainly in the husk, and as this ash is
very valuable as nourishment for the yeast plant, it is an open question
whether it would not be preferable to use for brewing purposes rice with
its husk. The comparatively largest amount of fat is contained in
maize; and as such oil is not desirable for brewing purposes, different
recommendations have been advanced for freeing the grain from it. In the
following table some of the mineral constituents of the three kinds of
grain are compared with each other. These data refer to 100 parts of
ash, and are taken from analysis given by Dr. Emil Wolf.
100 parts of
Potash Lime Magnesia Phosphoric Silica grain contain
acid ash.
Barley. 21.9 2.5 8.3 32.8 27.2 2.55 p. ct.
Rice with
husk. 18.4 5.1 8.6 47.2 0.6 7.84 "
Rice without
husk. 23.3 2.9 13.4 51.0 3.0 0.39 "
Maize. 27.0 2.7 14.6 44.7 2.2 1.42 "
The excessive amount of ash in rice with its husk is very remarkable,
and as this mineral matter consists to a great extent of phosphoric acid
and potash, the larger part of it is soluble in water. Consequently
on using rice with its husk for brewing purposes, the yeast will be
provided with a considerable amount of nutritive substance.
In conclusion it need hardly be mentioned that the use of rice with its
husk would also be of considerable pecuniary advantage. There is very
little oil in the husk of rice, as shown above by analysis, and it is
not likely that the flavor of the brew would suffer by it.--_London
Brewers' Journal._
* * * * *
PETROLEUM OILS.
Nothing is in more general use than petroleum, and but few things are
known less about by the majority of persons. It is hydra-headed. It
appears in many forms and under many names. "Burning fluid" is a popular
name with many unscrupulous dealers in the cheap and nasty. "Burning
fluid" is usually another name for naphtha, or something worse.
Gasoline, naphtha, benzine, kerosene, paraffine, and many other
dangerous fluids which make the fireman's vocation necessary are all the
product of petroleum. These oils are produced by the distillation or
refining of crude petroleum, and inasmuch as the public, especially
firemen, are daily brought into contact with them it is proper that
they should know something of their properties. Refining as commonly
practiced involves three successive operations. The apparatus employed
consists of an iron still connected with a coil or worm of wrought-iron
pipe, which is submerged in a tank of water for the purpose of cooling
it. The end of this pipe is fixed with a movable spout, which can be
transferred or switched from one to another of half a dozen pipes which
come around close to it, but which lead into different tanks containing
different grades of the distillate. When the still has been filled with
crude oil the fire is lighted beneath it, and soon the oil begins to
boil. The first products of distillation are gases which, at ordinary
temperatures, pass through the coil without being condensed, and escape.
When the vapors begin to condense in the worm the oil trickles from the
end of the coil into the pipe leading to the appropriate receiving tank.
The first oil obtained is known as gasoline, used in portable gas
machines for making illuminating gas. Then, in turn, come naphthas of
a greater or less gravity, benzine, high test water white burning oil,
such as Pratt's Astral common burning oil or kerosene, and paraffine
oils. When the oil has been distilled it is by no means fit for use,
having a dirty color and most offensive smell; it is then refined. For
this purpose it is pumped into a large vat or agitator, which holds from
two hundred and fifty to one thousand barrels. There is then added to
the oil about two per cent, of its volume of the strongest sulphuric
acid. The whole mixture is then agitated by means of air pumps, which
bring as much as possible every particle of oil in contact with the
acid. The acid has no affinity for the oil, but it has for the tarry
substance in it which discolors it, and, after the agitation, the acid
with the tar settles to the bottom of the agitator, and the mixture is
drawn off into a lead-lined tank. After the removal of the acid and tar,
the clear oil is agitated with either caustic soda or ammonia and water.
The alkali neutralizes the acid remaining in the oil, and the water
removes the alkali, when the process of refining is finished. A few
refiners improve the quality of their refined oil by redistilling it
after treating it with acid and alkali. All distillates of petroleum
have to be treated with acid and alkali to refine them. There is one
thing peculiar about the distillates of petroleum, and that is that the
run which follows naphtha, which is called "the middle run oil," is the
highest test oil that is made, running as high as 150 and 160 degrees
flash, while the common oil which follows, viz., from 45 down to 33
degrees Baume, will range at only about 100 flash, or 115 and 120
degrees burning lest.
An oil that will stand 100 flash will stand 110 burning test every time.
Kerosene oil, at ordinary temperature, should extinguish a match as
readily as water. When heated it should not evolve an inflammable vapor
below 110 degrees, or, better, 120 degrees Fahrenheit, and should not
take fire below 125 to 140 degrees Fahrenheit. As the temperature in a
burning lamp rarely exceeds 100 degrees Fahrenheit, such an oil would
be safe. It would produce no vapors to mix with the air in the lamp and
make an explosive mixture; and, if the lamp should be overturned, or
broken, the oil would not be liable to take fire. The crude naphtha
sells at from three to five cents per gallon, while the refined
petroleum or kerosene sells at from fifteen to twenty cents. As great
competition exists among the refiners, there is a strong inducement to
turn the heavier portions of the naphtha into the kerosene tank, so as
to get for it the price of kerosene. In this way the inflammable naphtha
or benzine is sometimes mixed with the kerosene, rendering the whole
highly dangerous. Dr. D. B. White, President of the Board of Health
of New Orleans, found that experimenting on oil which flashed at 113
degrees Fahrenheit, an addition of one per cent. of naphtha caused it to
flash at 103 degrees; two per cent. brought the flashing point down to
92 degrees, five per cent. to 83 degrees, ten per cent. to 59 degrees,
and twenty per cent. of naphtha added brought the flashing point down to
40 degrees Fahrenheit. After the addition of twenty per cent. of naphtha
the oil burned at 50 degrees Fahrenheit. There are two distinct tests
for oil, the flashing test and the burning test. The flashing test
determines the flashing point of the oil, or the lowest temperature at
which it gives off an inflammable vapor. This is the most important
test, as it is the inflammable vapor, evolved at atmospheric
temperatures, that causes most accidents. Moreover, an oil which has
a high flashing test is sure to have a high burning test, while the
reverse is not true. The burning test fixes the burning point of the
oil, or the lowest temperature at which it takes fire. The burning
point of an oil is from ten to fifty degrees Fahrenheit higher than the
flashing point. The two points are quite independent of each other; the
flashing point depends upon the amount of the most volatile constituents
present, such as naphtha, etc., while the burning point depends upon the
general character of the whole oil. One per cent. of naphtha will lower
the flashing point of an oil ten degrees without materially affecting
the burning test. The burning test does not determine the real safety
of the oil, that is, the absence of naphtha. The flashing test should,
therefore, be the only test, and the higher the flashing point the safer
the oil.
In regard to the danger of using the lighter petroleum oils, the
following, under the head of "Naphtha and Benzine under False Names," is
taken from Prof. C. F. Chandler's article on "Petroleum" in Johnson's
Cyclopedia. He says: "Processes have been patented, and venders have
sold rights throughout the country, for patented and secret processes
for rendering gasoline, naphtha, and benzine non-explosive. Thus
treated, these explosive oils, just as explosive as before the
treatment, are sold throughout the country under trade names. These
processes are not only totally ineffective, but they are ridiculous.
Roots, gums, barks, and salts are turned indiscriminately into the
benzine, to leave it just as explosive as before. No wonder we have
kerosene accidents, with agents scattered through the country selling
county rights and teaching retail dealers how to make these murderous
'non-explosive' oils. The experiments these venders make to deceive
their dupes are very convincing. None of the petroleum products
are explosive _per se_, nor are their vapors explosive under all
circumstances when mixed with air. A certain ratio of air to vapor is
necessary to make an explosive mixture. Equal volumes of vapor and air
will not explode; three parts of air and one of vapor gives a vigorous
puff when ignited in a vessel; five volumes of air to one of vapor gives
a loud report. The maximum degree of violence results from the explosion
of eight or nine parts of air mixed with vapor. It requires considerable
skill to make at will an explosive mixture with air and naphtha, and it
is consequently very easy for the vender not to make one. In most cases
the proportion of vapor is too great, and on bringing a flame in contact
with the mixture it burns quietly. The vender, to make his oil appear
non-explosive, unscrews the wick-tube and applies a match, when the
vapor in the lamp quietly takes fire and burns without explosion. Or he
pours some of the 'safety oil' into a saucer and lights it. There is no
explosion, and ignorant persons, biased by the saving of a few cents
per gallon, purchase the most dangerous oils in the market. It is not
possible to make gasoline, naphtha, or benzine safe by any addition that
can be made to it. Nor is any oil safe that can be set on fire at the
ordinary temperature of the air. Nothing but the most stringent laws,
making it a State prison offense to mix naphtha and illuminating oil, or
to sell any product of petroleum as an illuminating oil or fluid to be
used in lamps, or to be burned, except in air gas machines, that will
evolve an inflammable vapor below 100 degrees, or better, 120 degrees
Fahrenheit, will be effectual in remedying the evil. In case of an
accident from the sale of oil below the standard, the seller should be
compelled to pay all damages to property, and, if a life is sacrificed,
should be punished for manslaughter. It should be made extremely
hazardous to sell such oils." Prof Chandler is professor of analytical
chemistry, School of Mines, Columbia College.
There is no substance on earth, or under the earth, which will
chemically combine with naphtha, or that will destroy its peculiar
volatile and explosive properties. The manufacturers of petroleum
products have exhausted the whole resources of chemistry to make this
product available as a safe burning oil, and their inability to do so
proclaims the fact that it cannot be done. Chemistry has shown that
naphtha, and, in fact, the other products of petroleum, will not part
with their hydrogen or change the nature of their compounds, except by
decomposition from a union with oxygen, that is, by combustion. These
humbugs, who deceive people for their own gains, may put camphor, salt,
alum, potatoes, etc., into naphtha, and call it by whatever fancy name
they please. The camphor is dissolved, the salt partially; potatoes have
no effect whatever. The camphor may disguise the smell of the naphtha,
and sometimes myrhane or burnt almonds may be used for the same purpose.
But, no matter what is used, the liability to explosion is not lessened
in any degree. The stuff is always dangerous and always will be. There
is not much danger in the use of kerosene, if it is of the standard
required by law in several of the States. At the same time petroleum is
dangerous under certain conditions. Where oil is heated it is more or
less inflammable, and, in fact, inflammability is only a question of
temperature of the oil, after all. Burning oils should be kept in a
moderately cool place, and always with care. Of course, if a lighted
lamp is dropped and broken, the oil is liable to take fire, though the
lamp may be put out in the fall, or the light drowned by the oil, or the
oil not take fire at all. This will be the effect if the oil is cool and
of high flash test. When a lamp is lighted, and remains burning for some
time, it should never be turned down and set aside. The theory is, that
while lighting, a certain supply of gas is created from the oil, and
that when the wick is turned down that supply still continues to flow
out, and not being consumed, forms an inflammable gas in the chimney,
which will explode when a sufficient quantity of air is mixed with it
in the presence of light, which may happen if a person blows down the
chimney; but a lamp should never be extinguished in that way. A good,
high test kerosene oil can be made with ordinary care as safe as sperm
oil, though, of course, it is not so safe as a matter of fact. We are
sure to hear of it when an accident happens, but we never hear of the
reckless use of kerosene where an accident does not occur, and yet
there are few things so generally carelessly handled as burning
oils.--_Fireman's Journal_
* * * * *
COMPOSITION OF THE PETROLEUM OF THE CAUCASUS.
By MM. P SCHUTZENBERGER and N. TONINE.
All portions of this petroleum contain saturated carbides of the formula
C_nH_{2n}, which the authors name paraffenes. At a bright red heat they
yield benzinic carbides, C_nH_{2n-6}, naphthalin and a little anthracen.
At dull redness the products are along with unaltered paraffenes,
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