348 C H E M 
till all the alcohol is extracted ; the laft produfft is the 
fveakeft of cotirfe. By diftiilin'g this alcohol over again, 
and reducing it to about two-thirds of the quantity, it 
becomes very pure, and then is called r edified alcohol. 
.Lowitz fucceeded in depriving alcohol of all the water 
not neceflary to its compofition, by diddling it with a 
large quantity of alkali. To leparate this water, hr ft 
fhake the alcohol in a bottle together with dry potafh ; 
then pour as much of this alcohol over potafti ftrongly 
calcined, and ftill warm, as the fait will abforb ; it will 
take in general half its own weight. Adapt a receiver 
to the retort, and after twenty-four hours proceed to 
diftillation with fo gentle a heat, that the drops may fall 
only at an interval of two feconds. When the diftilla¬ 
tion ftackens, unlute the apparatus, and preferve the al¬ 
cohol which has pafled over; it is generally about two- 
thirds of the original quantity; that which comes over 
afterwards is Weaker, and at laft a pure phelgm. The 
fpecific weight of the alcohol thus obtained, is leflened 
from 815 to 791, at a temperature of 16 0 of Reaumur. 
The refiduum in the retort may ferve for frelh experi¬ 
ments, as long as any freftv portions of alcohol can be ab- 
forbed. There remains in the alembic a thick fluid, 
Which precipitates brown flocks, ariflng from fome drops 
of oil feparated in. the diftillation. 
Hence it may be obferved, that the purity and ftrength 
of alcohol muft differ according to the procefles ufed in 
obtaining it. A method of difcovering its parity has 
long been fought after.—It was formerly fuppofed that 
alcohol, which readily catches fire, and leaves no refidue, 
is very pure ; but it is at prefent well known, that the 
heat excited by its combuftion is fufliciently ftrong to dif- 
fipate all the phlegm it might contain.—Another proof 
has been propofed, by means of gunpowder: when al¬ 
cohol, fet on fire in a fpoon-upon gunpowder, does not 
inflame it, it is confidered as bad ; if, on the contrary, it 
fets it on fire, it is judged to be excellent. But this proof 
is very fallacious ; for, when a large quantity of the beft 
alcohol is burned on a fmall quantity of gunpowder, the 
water it affords during its combuftion moiftens the pow¬ 
der, and prevents its taking fire ; whereas it may be in¬ 
flamed by burning a very lmall quantity of phlegmatic 
alcohol on its furface. This method is therefore no more 
to be depended on than the former.—Boerhaave has de¬ 
ferred a very good procefs for afcertaining the purity of 
this fluid : it conflfts in throwing the very dry powder of 
carbonat of potafh into alcohol; this unites with the fu- 
perfluous water of the alcohol, and forms a more ponder¬ 
ous and coloured fluid than the alcohol, with which it 
does not mix, but falls to the bottom. Baume, on the 
consideration that alcohol is lighter the purer it is, has 
contrived an aerometer, by which the degree of purity 
of this fluid, and of all volatile liquors, may be accurately 
afeertained. When the inftrument is plunged in alcohol, 
it links deeper, in proportion as the fluid is purer. The 
method of conftru&ing this inftrument, as well as the 
refults afforded by different quantities of alcohol, may be 
feen in his Elements of Pharmacy, and may be applied 
to determine the ftrength of alcohol by the hydrometer. 
Rories’s aerometer is reckoned by Chaptal to be more 
correct than that of Baume, becaufe a thermometer is 
adapted to it. Perfectly rectified alcohol, according to 
Baume, fhould weigh butfixteen pennyweights ten grains 
in a bottle containing one ounce of water ; the tempe¬ 
rature is ro° above freezing. La Grange fays, that, when 
rubbed in the hands, it fhould evaporate quickly, leaving 
neither moifture nor fmell; if otherwife, it is badly rec¬ 
tified, and not pure. 
Having given the proceffes for obtaining it, we are now 
to examine the fubftance itfelf. 
Alcohol is a perfectly tranfparent fluid, much (harper 
and hotter than brandy, and much lighter ; the ftrongeft 
is from 38 to 40 0 . Its principal chemical property is it 
extreme volatility : it boils at 64°, and rifes in vapourss 
Heated with the contact of air, it boon takes fire, an 
3 
: S T R Y. 
exhibits a light flame, white m the 'middle, and blue at 
the fides ; it completely burns away, when pure. Many 
chemifts have attempted to difcov.erthe produft afforded 
by alcohol in burning. They found tluft its flame is ac¬ 
companied with neither foot nor fmoke; and that the 
volatilized matters when condenfed, are pure water, with¬ 
out tafte or fmell, abfolutely in the ftate of diftilied wa¬ 
ter. Boerhaave, from this phenomenon, fuppofed that 
the flame is produced by the water; and this opinion is 
confirmed by the knowledge we at prefent poffefs, re- 
fpefting hydrogen gas obtained by the de'compofition of 
water, and the water obtained by burning hydrogen gas 
with oxygen gas. Lavoifier dilcovered, that, when al¬ 
cohol is burned in a chimney adapted to receive the va¬ 
pours, a larger quantity of water is obtained than the 
whole of the fpirit made ufe of amounts to; whence it 
follows, that this liquor contains a large quantity of hy¬ 
drogen. 
If alcohol be pafled through a very hot porcelain tube, 
water is precipitated in the bottle adapted to the tube, 
and a very fmall quantity of carbonic acid is difengaged, 
and a little carbonated hydrogen gas ; a little naked car¬ 
bon remains in the tube. To perform this experiment, 
lay the porcelain tube through a furnace; to the upper 
extremity adapt a fyphon-tube, ending in a funnel; the 
lower extremity is to receive a recurved tube, which goes 
into a doubly-tubulated bottle, whence goes another tube 
which runs under a bell-glafs in the pneumatic-chemical 
apparatus. Make the porcelain tube red-hot, and pour 
in the alcohol by little and little through the funnel. 
This experiment proves that alcohol confifts of hydro¬ 
gen, carbon, and a fmall quantity of oxygen. 
Alcohol, expofed to the air, evaporates at a tempera¬ 
ture of io° above frezing. If water be poured over rec¬ 
tified alcohol, there is an increafe of heat, which arifes 
from the reciprocal adlion of the two fubftances upon each 
other. Thisfolution produces fpirits, whofe ftrengths are 
greater in proportion as the quantity of alcohol is greater. 
If fnow or ice be ufed inftead of water, its mixture with 
alcohol makes the thermometer fall 17 0 which, accord¬ 
ing to Baume, arifes from the great tendency of that 
fluid to evaporate. 
Alcohol combines in general with Ample combuftible 
bodies, but with different degrees of facility. 
Sulphur readily unites with alcohol. Phofphorus 
digefted with alcohol, changes into a kind of white 
tranfparent oil, remaining at the bottom of the vef- 
fel undiflblved. This oil does not congeal but in a 
great degree of cold ; but, by frequent wafhings, the 
phofphorus recovers its confiftence; after which it takes 
fire more readily by heat, but no longer fhines in the 
dark, and lofes its yellow colour; though the liquor 
drawn off from this oil fmells ftrongly of phofphorus, it 
has but a flight luminous power, which it ftievvs the mo¬ 
ment it is mixed with water. If the combination of 
phofphorus and alcohol be diftilied in a gentle heat, and 
the diftillation be flopped in time, phofphorus in cryftals 
may be obtained by cooling. This combination, with the 
addition of water, precipitates phofphorus. The ftrong 
acids and alcohol adl very ftrongly upon each other; and 
by this reciprocal adtion ether is produced. From the 
mixture of an acid with alcohol in certain proportions, 
arife the preparations called dulcified adds. 
Three parts of alcohol mixed with one part of fulphu- 
ric acid, produce a liquor which retains the name of Ra¬ 
id's water, though the inventor’s procefs was very dif¬ 
ferent and very complicated, like molt of the receipts 
of the old chemifts. Dulcified fpirit of nitre, now called 
nitric alcohol , is made alfo with great facility. Put two 
parts of alcohol over one of nitric acid, 'and leave them 
to digeft in the cold for twelve days: the acid will be 
confiderably foftened; it is now only an aperitive, or 
diuretic. 
Two parts of alcohol and one of muriatic acid digefted 
together, yield what is called fweet ffirit of fait. This 
is- 
