Scientific American Supplement, No. 365, December 30, 1882
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SCIENTIFIC AMERICAN SUPPLEMENT NO. 365
NEW YORK, DECEMBER 30, 1882.
Scientific American Supplement. Vol. XIV., No. 365.
Scientific American established 1845
Scientific American Supplement, $5 a year.
Scientific American and Supplement, $7 a year.
* * * * *
TABLE OF CONTENTS.
I. ENGINEERING AND MECHANICS.--Louis Favre, Constructor
of the St. Gothard Tunnel.--2 figures.--Portrait and
monument at Turin to commemorate the tunneling of the
Alps 5817
The New Harbor of Vera Cruz.--New artificial harbor
for Vera Cruz.--Capt. Eads's plan.--1 figure.--Plan
of harbor and improvement 5818
Cost of Power to Make Flour 5818
Driving gear Mechanism for Lift Hammers.--2 figures 5819
De Junker and Ruh's Machine for Cutting Annular
Wheels.--3 figures 5819
Recent Hydraulic Experiments.--Results of experiments
on the flow of water in the Ganges Canal 5819
The Germ: Shall It be Retained in Flour? By Arthur
Atkins 5820
Wheat Tests 5820
II. TECHNOLOGY AND CHEMISTRY.--Apparatus for Manufacturing
Gaseous or Aerated Beverages.--11 figures.--Bicarbonate
of soda apparatus. Generator. Washer.--Suction
pump.--Saturator.--Apparatus for using carbonate of
lime.--Apparatus completely mechanical in operation 5815
Detection and Estimation of Fusel Oil 5816
On Silicon.--Curious formation of silicide of platinum 5816
Stannous Nitrates.--The formation of explosive
compounds in machines by the corrosion of bronze and
tin solder 5816
Metallic Thorium. By L.F. Nilson 5816
Friedrich Woehler.--Obituary notice of the great German
chemist 5816
Apparatus for Printing by the Blue Process. By
Channing Whitaker.--3 figures 5820
III. ELECTRICITY, LIGHT, HEAT, ETC.--Spectrum Gratings 5822
A New Pocket Opera Glass.--4 figures 5822
Atoms, Molecules, and Ether Waves. By JOHN TYNDALL.
Action of heat and light on molecules.--Heat as an
agent in exploring molecular conditions.--The results
of a recent incursion into the extra-sensible world
of atoms and molecules 5823
Apparatus for Measuring Electricity at the Upper
School of Telegraphy. By E. MERCADIER.--5 figures.
Constant vibrator.--The Electrical tuning fork.
Arrangement for testing electric piles.--Very rapid
electric tuning fork.--A vibrating micrometer 5824
IV. NATURAL HISTORY.--Our Origin as a Species. By RICHARD
OWEN.--The Neanderthal skull.--Differential characters
between the lowest _Homo_ and the highest _Simia_ 5825
The Aba or Odika. By Dr. W.H. BACHELER.--A remarkable
tree of West Africa 5826
California Cedars 5826
* * * * *
APPARATUS FOR MANUFACTURING GASEOUS OR AERATED BEVERAGES.
The apparatus employed at present for making gaseous beverages are
divided into two classes--intermittent apparatus based on chemical
compression, and continuous ones based on mechanical compression.
The first are simple in appearance and occupy small space, but their use
is attended with too great inconveniences and losses to allow them to be
employed in cases where the manufacture is of any extent, so the
continuous apparatus are more and more preferred by those engaged in the
industry.
Continuous apparatus, however, other than those that we now propose to
occupy ourselves with, are not without some defects, for the gas is
produced in them intermittingly and at intervals, and more rapidly than
it is used, thus necessitating the use of a gasometer, numerous and
large washers, complicated piping, and, besides, of an acid cock.
To get rid of such drawbacks, it became necessary to seek a means of
rendering the production of the gas continuous, and of regulating it
automatically without the aid of the operator. Mr. Mondollot has
obtained such a result through a happy modification of the primitive
system of the English engineer Bramah. He preserves the suction and
force pump but, while applying it to the same uses, he likewise employs
it, by the aid of a special arrangement, so as to distribute the
sulphuric acid automatically over the chalk in the generator, and to
thus obtain a regular and continuous disengagement of carbonic acid gas.
The dangers and difficulties in the maneuver of an acid cock are
obviated, the gasometer and its cumbersome accessories are dispensed
with, and the purification is more certain, owing to the regularity with
which the gas traverses the washers.
In the accompanying plate we have figured three types of these
apparatus. The first that we shall describe is arranged for the use of
bicarbonate of soda. This apparatus consists (1) of a _generator_, C D,
(2) of a double _washer_ G G, (3) of a _suction pump_, P, and (4) of a
_saturator_, S (See Figs 1 to 9).
_The Generator._--This consists of a cylindrical leaden receptacle, D,
on the bottom of which rests a leaden bell containing apertures, c, at
its base. A partition, c, into which is screwed a leaden tube, C,
containing apertures divides the interior of the bell into two
compartments. The upper of these latter is surmounted by a mouth, B,
closed by a clamp, and through which the bicarbonate of soda is
introduced. A definite quantity of water and sulphuric acid having been
poured into the receptacle, D, a level tends to take place between the
latter and the bell, C, the liquid passing through the apertures. But
the acidulated water, coming in contact with the soda, sets free
carbonic acid gas, which, having no exit, forces the water back and
stops the production of gas until the apparatus is set in motion. At
this moment, the suction of the pump causes a new inflow of acidulated
water upon the soda, from whence another disengagement of gas, and then
a momentary forcing of the water, whose level thus alternately rises and
falls and causes a continuous production of gas proportionate with the
suction of the pump.
The consumption of soda and acid is about 2 kilogrammes each for
charging 100 siphons or 150 bottles. The bicarbonate is known to be used
up when the liquid in the generator is seen to descend to the bottom of
the water level, n, fixed to the vessel, D.
_The Washer_ (Figs 1 and 4)--The gas, on leaving the generator, enters
the washer through a bent copper pipe, R. The washer is formed of two
ovoid glass flasks G G, mounted on a bronze piece, L, to which they are
fixed by screw rings, l, of the same metal. The two flasks, G G,
communicate with each other only through the tinned-copper tube q,
which is held in the mounting q, of the same metal. This latter is
screwed into the piece, L, and contains numerous apertures, through
which the gas coming in from the pipe, R, passes to reach the upper
flask, G. The gas is washed by bubbling up through water that has been
introduced through the cock, R. After it has traversed both flasks, it
escapes through the copper pipe, p, into which it is sucked by the
pump, P.
_The Pump_ (Figs 1, 5 and 6)--This consists of a cylindrical chamber, P,
of bronze, bolted to a bracket on the frame, and cast in a piece, with
the suction valve chamber, P, in which the valve, p, plays. It is
surmounted by the distributing valve chamber P squared. This latter is held
by means of two nuts screwed on to the extremity of the rods, p cubed,
connected with the shell, E, of the distributing-cock, E. In the shell,
E, terminates, on one side, the pipe, p, through which enters the gas
from the washer, and, on the other, the pipe i, that communicates with
a feed-reservoir not shown in the cuts. The cock E, permits of the
simultaneous regulation of the entrance of the gas and water. Its
position is shown by an index e, passing over a graduated dial, _eš_.
From the distributing valve chamber, P squared the pipe, s, leads the
mixture of water and gas under pressure into
_The Saturator_, S (Figs 1, 7 and 9)--This consists of a large copper
vessel, s, affixed to the top of the frame through the intermedium of
a bronze collar h, and a self closing bottom H. This latter is
provided with two pipes, one of which, s, leads the mixture of water
and carbonic acid forced by the pump, and the other, b, communicates
with the siphons or bottles to be filled. The pipe, b, is not affixed
directly to the bottom, but is connected therewith through the
intermedium of a cock, r. The object of the broken form of this pipe
is to cause the pressure to act according to the axis of the screw, r,
which is maneuvered by the key, r squared.
The water under pressure, having been forced into the vessel, S, is
submitted therein to an agitation that allows it to dissolve a larger
quantity of gas. Such agitation is produced by two pairs of paddles, J
J, mounted at the extremity of an axle actuated by the wheel, A, through
the intermedium of gearings, g and g.
The course of the operation in the saturator may be followed by an
inspection of the water level, n, seen at the front and side in Figs.
2 and 3. This apparatus, in which the pressure reaches 4 to 6
atmospheres in the manufacture of Seltzer water or gaseous lemonade in
bottles, and from 10 to 12 atmospheres in that of Seltzer water in
siphons, is provided also with a pressure gauge, m, and a safety
valve, both screwed, as is also the tube, n squared, into a sphere, S, on
the top of the saturator.
_Apparatus for Using Carbonate of Lime_ (Figs 2, 3, and 10)--When chalk
is acted upon by sulphuric acid, there is formed an insoluble sulphate
which, by covering the chalk, prevents the action of the acid from
continuing if care be not taken to constantly agitate the materials.
This has led to a change in the arrangement of the generator in the
apparatus designed for the use of chalk.
It consists in this case of a leaden vessel, D, having a hemispherical
bottom set into a cylindrical cast iron base, K, and of an agitator
similar to that shown in Fig. 11, for keeping the chalk in suspension in
the water. These latter materials are introduced through the mouth, B
(Fig. 3). Then a special receptacle, C, of lead, shown in detail in Fig.
10, and the cock, c, of which is kept closed, is filled with sulphuric
acid. The acid is not introduced directly into the vessel, C, but is
poured into the cylinder, C, whose sides contain numerous apertures
which prevent foreign materials from passing into the siphon tube c,
and obstructing it.
To put the apparatus in operation, the acid cock, c, is opened and the
wheel, A, is turned, thus setting in motion both the pump piston, P, and
the agitator, within S and D. Then the play of the pump produces a
suction in the washers and from thence in the generator and causes the
acid in the vessel, C, to flow into the generator through the leaden
siphon tubes, c. Coming in contact with the chalk in suspension, the
acid produces a disengagement of gas which soon establishes sufficient
pressure to stop the flow of the acid and drive it back into the siphon
tube. The play of the pump continuing, a new suction takes place and
consequently a momentary flow of acid and a new disengagement of gas.
Thus the production of the latter is continuous, and is regulated by the
very action of the pump, without the operator having to maneuver an
acid-cock. The latter he only has to open when he sets the apparatus in
operation, and to close it when he stops it.
The arrangement of the washer is the same as in the preceding apparatus,
save that a larger cylindrical copper reservoir, G', is substituted for
the lower flask. The pump and saturator offer nothing peculiar.
A bent tube, u, which communicates with the generator, D, on one side,
and with a cylindrical tube, V, ending in a glass vessel on the other,
serves as a safety-valve for both the generator and the acid vessel.
The consumption of chalk is about 2.5 kilogrammes, and the same of acid,
for charging 100 siphons or 150 bottles. The apparatus shown in the
figure is capable of charging 600 siphons or 900 bottles per day.
_An Apparatus Completely Mechanical in Operation_ (Fig. 11).--This
apparatus consists of two very distinct parts. The saturator, pump, and
driving shaft are supported by a hollow base, in whose interior are
placed a copper washer and the water-inlet controlled by a float-cock.
This part of the apparatus is not shown in the plate. The generator,
partially shown in Fig. 11, is placed on a base of its own, and is
connected by a pipe with the rest of the apparatus. It consists of two
similar generators, D, made of copper lined with lead, and working
alternately, so as to avoid all stoppages in the manufacture when the
materials are being renewed. The pipe, d, connecting the two parts of
the apparatus forks so as to lead the gas from one or the other of the
generators, whence it passes into the copper washer within the base,
then into the glass indicating washer, and then to the pump which forces
it into the saturator.
Each of the generators communicates by special pipes, a, with a single
safety vessel, V, that operates the same as in the preceding apparatus.
The agitator, Q, is of bronze, and is curved as shown in Fig. 11.
The production of this type of apparatus is dependent upon the number of
siphons that can be filled by a siphon filler working without
interruption.--_Machines, Outils et Appareils._
* * * * *
DETECTION AND ESTIMATION OF FUSEL OIL.
Until quite recently we have had no accurate method for the
determination of fusel oil in alcohol or brandy. In 1837 Meurer
suggested a solution of one part of silver nitrate in nine parts of
water as a reagent for its detection, stating that when added to alcohol
containing fusel oil, a reddish brown color is produced, and in case
large quantities are present, a dark brown precipitate is formed. It was
soon found, however, that other substances than amyl alcohol produce
brown colored solutions with silver nitrate; and Bouvier[1] observed
that on adding potassium iodide to alcohol containing fusel oil, the
solution is colored yellow, from the decomposition of the iodide.
Subsequently Boettger[2] proved that potassium iodide is not decomposed
by pure amyl alcohol, and that the decomposition is due to the presence
of acids contained in fusel oil. More accurate results are obtained by
using a very dilute solution of potassium permanganate, which is
decomposed by amyl alcohol much more rapidly than by ethyl alcohol.
[Footnote 1: Zeitschrift f. Anal. Chem. xi., 343.]
[Footnote 2: Dingler's Polytech. Jour., ccxii., 516.]
Depre[3] determines fusel oil by oxidizing a definite quantity of the
alcohol in a closed vessel with potassium bichromate and sulphuric acid.
after removal of excess of the oxidizing reagents, the organic acids are
distilled, and, by repeated fractional distillation, the acetic acid is
separated as completely as possible. The remaining acids are saturated
with barium hydroxide, and the salts analyzed; a difference between the
percentage of barium found and that of barium in barium acetate proves
the presence of fusel oil, and the amount of difference gives some idea
of its quantity. Betelli[4] dilutes 5 c.c. of the alcohol to be tested
with 6 to 7 volumes of water, and adds 15 to 20 drops of chloroform and
shakes thoroughly. If fusel oil is present, its odor may be detected by
evaporating the chloroform; or, by treatment with sulphuric acid and
sodium acetate, the ether is obtained, which can be readily recognized.
Jorissen[5] tests for fusel oil by adding 10 drops of colorless aniline
and 2 to 3 drops of hydrochloric acid to 10 c.c. of the alcohol. In the
presence of fusel oil a red color is produced within a short time, which
can be detected when not more than 0.1 per cent. is present. But
Foerster[6] objects to this method because he finds the color to be due
to the presence of furfurol, and that pure amyl alcohol gives no color
with aniline and hydrochloric acid.
[Footnote 3: Pharm. J. Trans. [3] vi., 867.]
[Footnote 4: Berichte d. Deutschen Chem. Gesellsch., viii., 72.]
[Footnote 5: Pharm. Centralhalle, xxii., 3.]
[Footnote 6: Berichte d. Deutsch. Chem. Gesellsch., xv., 230.]
Hager[7] detects fusel oil as follows: If the spirit contains more than
60 per cent. of alcohol, it is diluted with an equal volume of water and
some glycerine added, pieces of filter paper are then saturated with the
liquid and exposed to the After the evaporation of the alcohol, the odor
of the fusel oil can be readily detected. For the quantitative
determination he distills 100 c.c. of the alcohol in a flask of 150 to
200 c.c. capacity connected with a condenser, and so arranged that the
apparatus does not extend more than 20 cm. above the water bath. This
arrangement prevents the fusel oil from passing over. If the alcohol is
stronger than 70 per cent., and the height of the distillation apparatus
is not more than 17 cm., the residue in the flask may be weighed as
fusel oil. With a weaker alcohol, or an apparatus which projects further
out of the water bath, the residual fusel oil is mixed with water. It
can, however, be separated by adding strong alcohol and redistilling, or
by treating with ether, which dissolves the amyl alcohol, and
distilling, the temperature being raised finally to 60 deg..
[Footnote 7: Pharm. Centralhalle, xxii., 236.]
Marquardt,[8] like Betelli, extracts the fusel oil from alcohol by means
of chloroform, and by oxidation converts it into valeric acid. From the
quantity of barium valerate found he calculates the amount of amyl
alcohol present in the original solution; 150 c.c. of the spirit, which
has been diluted so as to contain 12 to 15 per cent. of alcohol, are
shaken up thoroughly with 50 c.c. of chloroform, the aqueous layer drawn
off, and shaken with a fresh portion of chloroform. This treatment is
repeated several times. The extracts are then united, and washed
repeatedly with water. The chloroform, which is now free from alcohol
and contains all the fusel oil, is treated with a solution of 5 grammes
of potassium bichromate in 30 grammes of water and 2 grammes of
sulphuric acid, and then heated in a closed flask for six hours on a
water bath at 85 deg.. The contents of the flask are then distilled, the
distillate saturated with barium carbonate, and the chloroform
distilled; the residue is evaporated to a small volume, the excess of
barium carbonate filtered off, and the filtrate evaporated to dryness
and weighed. The residue is dissolved in water, a few drops of nitric
acid added, and the solution divided into two portions. In the first
portion the barium is determined; in the second the barium chloride. The
total per cent. of barium minus that of barium chloride gives the amount
present as barium valerate, from which is calculated the per cent. of
amyl alcohol. By this process the author has determined one part of
fusel oil in ten thousand of alcohol. To detect very minute quantities
of fusel oil, the chloroform extracts are treated with several drops of
sulphuric acid and enough potassium permanganate to keep the solution
red for twenty-four hours. If allowed to stand in a test tube, the odor
of valeric aldehyde will first be noticed, then that of amyl valerate,
and lastly that of valeric acid.--_Amer. Chem. Journal._
[Footnote 8: Berichte d. Deutsch. Chem. Gesellsch., xv., 1,370
and 1,663.]
* * * * *
ON SILICON.
It is known that platinum heated in a forge fire, in contact with
carbon, becomes fusible. Boussingault has shown that this is due to the
formation of a silicide of platinum by means of the reduction of the
silica of the carbon by the metal. MM. P. Schuetzenberger and A. Colson
have produced the same phenomenon by heating to white heat a slip of
platinum in the center of a thick layer of lampblack free from silica.
The increase in weight of the metal and the augmentation of its
fusibility were found to be due, in this case also, to a combination
with silicon. As the silicon could not come directly from the carbon
which surrounded the platinum, MM. Schuetzenberger and Colson have
endeavored to discover under what form it could pass from the walls of
the crucible through a layer of lampblack several centimeters in
thickness, in spite of a volatility amounting to almost nothing under
the conditions of the experiment. They describe the following
experiments as serving to throw some light upon the question:
1. A thin slip of platinum rolled in a spiral is placed in a small
crucible of retort carbon closed by a turned cover of the same material.
This is placed in a second larger crucible of refractory clay, and the
intervening space filled with lampblack tightly packed. The whole is
then heated to white heat for an hour and a half in a good wind furnace.
After cooling, the platinum is generally found to have been fused into a
button, with a marked increase in weight due to taking up silicon, which
has penetrated in the form of vapor through the walls of the interior
crucible.
2. If, in the preceding experiment, the lampblack be replaced by a
mixture of lampblack and rutile in fine powder, the slip of platinum
remains absolutely intact, and does not change in weight. Thus the
titaniferous packing recommended by Sainte-Claire Deville for preventing
the access of nitrogen in experiments at high temperatures also prevents
the passage of silicon. A mixture of carbon and finely divided iron is,
on the contrary, ineffectual. These facts seem to indicate that nitrogen
plays a part in the transportation of the silicon, as this is only
prevented by the same means made use of in order to prevent the passage
of nitrogen.
3. The volatility of free silicon at a high temperature is too slight to
account for the alteration of the platinum at a distance. This can be
shown by placing several decigrammes of crystallized silicon on the
bottom of a small crucible of retort carbon, covering the silicon with a
small flat disk of retort carbon upon which is placed the slip of
platinum. The crucible, closed by its turned cover, is then enveloped in
a titaniferous packing and kept at a brilliant white heat for an hour
and a half. The metal is found to have only very slightly increased in
weight, and its properties remain unaltered. This experiment was
repeated several times with the same result. If, however, the
crystallized silicon be replaced by powdered calcined silica, the
platinum, placed upon the carbon disk, fuses and increases in weight,
while the silica loses weight. The theory of these curious phenomena is
very difficult to establish on account of the high temperatures which
are necessary for their manifestation, but it may be concluded, at
present, that nitrogen and probably oxygen also play some part in the
transportation of the silicon across the intervening space, and that the
carbosilicious compounds recently described by MM. Schuetzenberger and
Colson also take part in the phenomenon.--_Comptes Rendus_, xciv.,
1,710.--_Amer. Chem. Journal._
* * * * *
STANNOUS NITRATES.
At the Royal Powder Works at Spandau, Prussia, frequent ignition of the
powder at a certain stage of the process led to an examination of the
machinery, when it was found that where, at certain parts, bronze pieces
which were soldered were in constant contact with the moist powder, the
solder was much corroded and in part entirely destroyed, and that in the
joints had collected a substance which, on being scraped out with a
chisel, exploded with emission of sparks. It was suspected that the
formation of this explosive material was in some way connected with the
corrosion of the solder, and the subject was referred for investigation
to Rudolph Weber, of the School of Technology, at Berlin. The main
results of his investigation are here given.
The explosive properties of the substance indicated a probable
nitro-compound of one of the solder metals (tin and lead), and as the
lead salts are more stable and better understood than those of tin, it
was resolved to investigate the latter, in hope of obtaining a similar
explosive compound. Experiments on the action of moist potassium nitrate
on pure tin led to no result, as no explosive body was formed. Stannous
nitrate, Sn(NO_{3})_{2}, formed by the action of dilute nitric acid on
tin, has long been known, but only in solution, as it is decomposed on
evaporating. By adding freshly precipitated moist brown stannous oxide
to cool nitric acid of sp. gr. 1.20, as long as solution occurred, and
then cooling the solution to -20 deg., Weber obtained an abundance of
crystals of the composition Sn(NO_{3})_{2} + 20H_{2}O. They resemble
crystals of potassium chlorate. They cannot be kept, as they liquefy at
ordinary temperatures. An insoluble _basic_ salt was obtained by
digesting an excess of moist stannous oxide in solution of stannous
nitrate, or by adding to a solution of stannous nitrate by degrees, with
constant stirring, a quantity of sodium carbonate solution insufficient
for complete precipitation. Thus obtained, the basic salt, which has the
composition Sn_{2}N_{2}O_{7}, is a snow-white crystalline powder, which
is partially decomposed by water, and slowly oxidized by long exposure
to the air, or by heating to 100 deg.. By rapid heating to a higher
temperature, as well as by percussion and friction, it explodes
violently, giving off a shower of sparks. This compound is also formed
when a fine spray of nitric acid (sp. gr. 1.20) is thrown upon a surface
of tin or solder. It is also formed when tin or solder is exposed to the
action of a solution of copper nitrate, and thus formed presents the
properties already described.