$10 Alcohol.—Mr. Dalton on the Constitution of the Atmosphere. 
ACTION OF LIME ON ALCOHOL. 
It was known that when alcohol and lime are kept in con- 
tact, during a length of time, the alcohol becomes pale yellow *, 
Dr. Menici introduced into a vessel, three ounces of alcohol, 
of 35 degrees (B), and a similar quantity at 28, into another ; 
each vessel containing also an equal quantity of lime; and 
they were all exposed to the ordinary temperature, being 
previously well closed. At the end of four months, the liquor 
in the second vessel had become sensibly yellow, which soon 
became deeper, and in six months it was reddish. The alco- 
hol now restored reddened litmus, owing to the solution of 
lime. Submitted to distillation it afforded unaltered alcohol. 
The residual liquor, evaporated to dryness, afforded a sub- 
stance analogous to our black resin [colofonia rossastra],which, 
when kindled, burned brilliantly, with much smoke+. But 
the strong alcohol contained in the first bottle seemed not to 
have been, in any manner, affected; unless that it feebly re- 
stored the colour of reddened litmus.—( Giornale di Fisica.) 
Dublin Phil. Journ. —— : 
MR. DALTON ON THE CONSTITUTION OF THE ATMOSPHERE. 
The following is an abstract of Mr. Dalton’s paper on the 
constitution of the atmosphere, read before the Royal Society 
on the 23d of February last. 
After some preliminary remarks, the author observes, that 
whatever may be thought of Newton’s hypothesis as to elastic 
fluids, as far as the mechanical effects of such fluids are objects 
of inquiry, we may safely adopt it; namely, that each fluid zs 
constituted of particles repelling one another by forces inversely 
as their central distances, at least within ordinary limits of con- 
densation and rarefaction. - 
After adverting to the fact that mixtures of various elastic 
fluids, such as is the atmosphere, composed of atoms of dif- 
ferent volumes and elasticities, do notwithstanding observe the 
same laws of condensation and rarefaction as simple elastic 
fluids, and to the difficulties which this fact throws in the way - 
* Gay-Lussac first noticed this change of colour, while engaged in di- 
stilling alcohol off lime, which he proposed as a better method of obtaining 
alcohol than by means of muriate of lime. [Memoires d’ Arcueil, tome iil. 
.104.] But this method had been practised long before. See Hlémens 
de Pharmacie, par Baumé, 1770, p. 474.—Dus.tn Epi. 
+ When sulphuric acid and alcohol are distilled, as in the preparation 
of ether, towards the end of the process the mixture becomes black, and 
a black matter collects (if the quantity operated on be large) into a mass. 
This black mass is brittle; it may be melted; it solidifies on cooling: it is 
combustible, and burns with a smoky flame. It is, in fact, a kind of pitchy. 
matter, which seems very much to resemble this resin noticed by Dr. Me- 
nici.—Dvustiw Ent. 
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