THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[July 15,1S71. 
46 
gallons to the barrel, while of late years the writer never 
knew a barrel to overrun the gauge. And as the United 
States Inspector's certificate always certifies the gauge, 
the alcohol-maker throws himself upon this, and there is 
no redress. Besides this there can be nothing more 
clumsy, nor more difficult to comprehend in common 
usage, than the plan of defining the strength by degrees 
'above and below proof, and the quantity by proof gal¬ 
lons. If it was desirable to keep the consumers or users 
of alcohol so befogged that they could not detect defi¬ 
ciencies in strength or measure, hardly a better plan 
could be adopted, and the advisers or experts of the 
•General Government, who are responsible for the present 
method, could not have better subserved the interests of 
the Whisky Ring, or damaged the interests of the con¬ 
sumer had they been paid for it. 
The strength should always be indicated by percent¬ 
age of absolute alcohol by ivcight and not by volume, and 
tliis should be determined by apparent specific gravity. 
It should always be bought and sold by weight, the 
barrels being tared, just as castor oil, linseed oil, cotton¬ 
seed oil, etc., are of late years. 
Five gallons alcohol, specific gravity *8202 at lo - 6° C. 
— 60° F., measured at 21° C. = 09-8° F., weighs 34 lbs. 
.avoirdupois, or nearly 6 lbs. 13 oz. to the gallon. This 
alcohol contains about SI per cent, by weight of abso¬ 
lute alcohol. 
The officinal alcohol fortius, specific gravity ’817, con¬ 
taining about 92 per cent, of alcohol by weight, if mea¬ 
sured at 15-6° C. = 60° F., weighs just about the same. 
So that about 5-4° C. = 9-8° F. of temperature, is equal 
to 1 per cent, in strength. 
If bought and sold by weight, or by weight gallons, 
which would be the first step, temperature would not 
have to be taken into consideration. 
Alcohol of specific gravity ’81674 at 15’6° C. = 60° F., 
when weighed at 25° C. =* 77° F., has an apparent spe¬ 
cific gravity of -808767, and at 30-6° C. = 87° F., -80400, 
-or about *00085 for each Centigrade degree of tempera¬ 
ture. By apparent specific gravity is meant that although 
the alcohol is weighed at the higher temperature given, 
it is compared with the same volume of water at the 
lower temperature of 15-6° C. = 60° F. 
One pint of this alcohol, officinal “alcohol fortius,” 
at 10 - 6° C. = 51° F. weighs 387"72 gram. = 5983 grains, 
at 30-6° C. = 87° F. 379-87 „ = 5862 „ 
20° C. = 36° F. 7-85 „ = 121 „ 
Alcohol of specific gravity -82154 at 15-6° C. = 60° F. 
■when weighed at 25° C. = 77° F. has an apparent specific 
gravity of -81342, and at 30-6° C. = 87° F., -80889, or 
about "000843 for each Centigrade degree of temperature. 
One pint of this alcohol, which is about the common 
commercial strength, 
at 15-6° C. = 60° F. weighs 388-05 gram. = 5988 grains, 
at 25-6° C. = 78° F. 384-15 „ =5928 „ 
10° C. = 18°F. 3-90 „ = 60 „ 
The next alcoholic menstruum which the writer has 
bound necessary thus far, is a mixture of equal parts, by 
weight, of stronger alcohol and water. This mixture 
-rejects much more of the troublesome mucilaginous por¬ 
tions of such drugs as dandelion than the diluted alcohol 
•does. 
Equal weights of alcohol specific gravity -81953 at 
15-6° C. = 60° F., and water, give a mixture having a 
specific gravity 
at 15-6° C. = 60° F. -92858. 
at 25° = 77° F. -92003. Difference, -00089 for 
each 1° C. 
One pint of this mixture 
at 10-6° C. = 51° F. weighs 439-93 grm. = 6789 grains, 
at 30-6° C. = 87° F. „ 433-03 ‘ „ = 6682 „ 
20° C. = 36° F. 6-9 „ = 107 „ 
[To be continued.) 
DUST AND SMOKE. 
BY PROFESSOR TYNDALL. 
[Concluded from page 28.) 
"We have thus been led by our first unpractical experi¬ 
ments into a thicket of practical considerations. In 
taking the next step, a personal peculiarity had some in¬ 
fluence upon me. The only kind of fighting in which 
I take the least delight is the conflict of man with 
nature. I like to see a man conquer a peak or quench 
a conflagration. I remember clearly the interest I took 
twenty years ago in seeing the firemen of Berlin con¬ 
tending for mastery with a fire which had burst out 
somewhere near the Brandenburger Thor; and I have 
often experienced the same interest in the streets of 
London. Admiring as I do the energy and bravery of 
our firemen, and having heard that smoke was a greater 
enemy to them than flame itself, the desire arose of de¬ 
vising a fireman’s respirator. But before I describe what 
has been done in this direction, let me draw your atten¬ 
tion to the means hitherto employed to enable a man to 
live in dense smoke. Thanks to the courtesy of Captain 
Shaw, I am enabled to show you the action of the 
“ smoke-jacket,” known abroad as the “ Appareil Paulin,” 
from its supposed inventor. The jacket is of pliable 
cowhide. It has arms and a hood, with eye-glasses. 
With straps and buckles the jacket is tied round the 
wrists and waist, and a strap which passes between the 
legs prevents it from rising. On the left side of the 
jacket is fixed a screw, to which the ordinary hose of the 
fire-engine is attached, and through the hose air instead 
of water is urged into the space between the fireman’s 
body and the jacket. It becomes partially inflated, but 
no pressure of any amount is attainable, because the air, 
though somewhat retarded, escapes with tolerable free¬ 
dom from the wrists and waist. Hence the fireman, 
when his hose is long enough, can deliberately walk 
into the densest smoke or foulest air. But you see the 
use of the smoke-jacket necessitates the presence of 
several men; it also implies the presence of an engine. 
A single man could make no use of it, nor indeed 
any number of men without a pumping engine. Its 
uses are thus summed up in a communication addressed 
to me by Captain Shaw:— 
“ This smoke-jacket is very useful for extinguishing 
fires in vaults, stopping conflagrations in the holds of 
ships, and penetrating wells, quarries, mines, cesspools, 
etc.—any places, in short, where the air has become un¬ 
fit for respiration. 
“The special advantages of this jacket are its great 
simplicity, its facility for use, and the rapidity with 
which it can be carried about and put on; but its draw¬ 
back is, that it requires the use of an engine or air- 
pump, and, consequently, is of no service to one man 
alone. For this latter reason smoke-jackets, although 
very effective for enabling us to get into convenient 
places for extinguishing fires, have very rarely proved 
of any avail for saving life.” 
Now it is that very want that I thought ought to be 
supplied by a suitable respirator. Our fire-escapes are 
each in charge of a single man, and I wished to be able 
to place it in the power of each of those men to penetrate 
through the densest smoke into the recesses of a house, 
and there to rescue those who would otherwise be suf¬ 
focated or burnt. I thought that cotton-wool, which so 
effectually arrested dust, might also be influential in 
