* 
New Heliometer. 463 
that we may separate the effects-which belong to the liquid and 
to its envelepe, and appreciate their influence with sufficient ac- 
curacy to recovery, by calculation alone all the results observed ; 
so that calculators may in future dispense, in an infinite number 
of cases, with immediate observation, and we may introduce 
with confidence its data into the elements of phenomena. This 
is an advantage of the more consequence, as these kinds of re- 
searches are extremely delicate ; and if we do not pay the great- - 
est attention to them, a multitude of trifling causes will disturb 
the observer. “fe 
A dispute has long existed among chemists, as to the precise’ 
moment at which alcohol was formed.in wine. The greater num- 
ber formerly thought that alcohol, or spirits of wine, was an essen- 
tial product of fermentation; but M. Fabroni has maintained a 
contrary opinion. According to him, it is only accidentally, and 
when it excites too much heat, that fermentation engenders alco- 
hol ; but in common wines, the alcohol is produced merely by 
the heat applied for their distillation ; and the chief proof which 
he gives of this is, that we cannot extract it from these wines hy 
potash, although the latter exposes the slightest particle of al- 
cohol which we introduce on purpose. . M. Gay-Lussac has ad- 
hered to the old opinion, by showing that potash also demon- 
states the alcohol which is natural to wine, when we previously 
cleanse it by litharge from the principles which surrounded it 
and opposed its separation ; and that we may obtain this spiri- 
tuous liquor by distilling wine at a temperature of 15 degrees, 
which is far inferior to that of the common fermentation. M. 
Gay-Lussac, to avoid all adulteration, made the wine himself 
upon which he made his experiments, and found alcohol in it as 
well as in the other kinds. He has also shown that we may ob- 
tain the pure alcohol of Richter by employing quicklime, or ra- 
ther barytes, instead of muriate of lime. 
[ Yo be continued. | 
XCIX. Intelligence and Miscellaneous Articles. 
O; the 13th of June 1814, the first Class of the French In- 
stitute (being that for the encouragement of mathematics and 
the physical sciences) held a meeting, when a paper was read 
with the following title: “ Account of a new Heliometer, in- 
tended to give the precise measurement of the diameter of the 
Sun, by Alexis Rochon, member of the Institute, and of the 
Academy of St. Petersburgh.” After stating that the subject 
had been propounded as a prize dissertation by the Petersburgh 
Academy for last year, M. Rochon proceeds; ¢ In the Moniteur 
for, 
