‘Chemical Sciences 173 
with a dense green flame, and the production of much muriatic 
acid, it was soluble in alcohol, but insoluble in water, at the bottom 
of which it lay in drops. 
Finally, MM. Macaire and Marcet’ proceeded to analyze these 
fluids, and this they effected by oxide of copper: one hundred 
parts of the pyroxilic spirit or pyroligneous ether gave 
44.53 of carbon, or 6 atoms. 
46.61. oxygen, 4 ,, 
9.16 hydrogen, 7 ,, 
One hundred parts of the pyroacetic spirit of Chenevix gave 
55.30 of carbon, or 4 atoms, 
36.50 oxygen, 2 ,, 
8.20 hydrogen 3 ,, 
Analyzing alcohol of specific gravity .820 at the same time, one 
hundredparts gave 
48.8 of carbon, or 3 atoms. 
39.9 ., oxygen, 2 ,, 
11.3, hydrogen 5 ,, 
’ The conclusions of the mémoire are, lst. That there exist at 
least two simple vegetable fluids distinct from alcohol, but like 
that liquid, having the property of forming with acids, particular 
ethereal spirits ; 2nd. That these two fluids which may be distin- 
guished by the names pyroacetic spirit and pyroxilic spirit, differ 
from each other, both in their properties and composition. — Bib. 
Univ. xxiv. 126. 
We suspect some mistake in the printing of the figures of the 
analysis, for there is no accordance in the estimation of the weight 
of the atoms deduced from them. If the weights expressed be di- 
vided by the number of atoms assigned, and the whole be reduced 
to the atom of hydrogen, as unity it gives the weight of an atom 
of carbon 5.67 by the first analysis, 5.06 by the second, and 7.2 
by the third, and the weight of an atom of oxygen as 8.9 by the 
first analysis, 6.67 by the second, and 8,82 by the third. — Ed. 
29. Cafeine.—Cafeine is a crystallizable principle discovered in 
1821, in coffee, by M. Robiquet, whilst searching in it for quina. 
MM. Pelletier and Caventour obtained this substance at the 
same time, but did not complete their researches. M. Robiquet 
read a mémoire on this subject to the Société de Pharmacie of 
Paris, which has not been published. It is, however, known to be 
a new principle, white, crystalline, volatile, and slightly solubl—e. 
Dict, de Med. 
