xxiv - Historical Sketch of the Physical Sciences, 1818. 
acids upon the colouring matter of cochineal when at a maximum 
of oxidation, but like alkalies when at a minimum or medium 
degree ; and that this alkaline influence may be exercised in the 
midst of an acid when the oxides in question are capable of 
forming an insoluble precipitate with the colouring matter. 
Tannin, and astringent substances in general, do not precipitate 
the colouring matter of cochineal. 
Pelletier and Caventon mixed a quantity of the colouring 
matter with black oxide of copper, and subjected the mixture to 
the requisite degree of heat. The only gaseous substance 
obtained was carbonic acid. Hence it follows that carmine is 
composed of carbon, oxygen, and hydrogen, and that it contains 
no azote whatever. 
- The peculiar animal matter of cochineal has a good deal of 
resemblance to gelatine ; but it is distinguished by peculiarities 
which render it necessary to consider it as a peculiar substance. 
But fora minute account of the characters of this body, and of 
the fatty matter of cochineal, I must refer the reader to the disser- 
tation of Pelletier and Caventon itself—(See Ann. de Chim. et 
Phys. viii, 250.) 
2. White Matter deposited by the Aphis Euonymus.—M. Las- 
geigne collected a quantity of white matter deposited upon the 
leaves of the Euonymus Europea by an aphis that inhabits these 
leaves, and subjected it to the following trials : 
(1.) It was white, without smell; but having a pleasantly 
. sweet taste. Cold water dissolved it readily. Cold alcohol did 
not act upon it; but hot alcohol dissolved it, with the exception 
of some white flocks possessing the characters of albumen. On 
cooling, the alcohol allowed the substance to precipitate in small, | 
white, brilliant grains, which had a sweet taste. 
_(2.) These grains, when heated in a retort, produced a quantity 
of very acid oil. 
_(3.) The aqueous solution was not precipitated by acetate or 
subacetate. of lead, nitrate of silver, or nitrate of mercury. 
Neither was any precipitate produced by the alkalies, the infusion 
of nutgalls, or the aqueous solution of chlorine. 
'(4.) Nitric acid converted it into oxalic acid. 
{5,) When mixed with yeast, it gave no indication of fermen- 
tation, ; 
From these properties, M. Lasseigne considers it as a species 
ef manna.—(Jour. de Pharmacie, 1818, p. 526.) 
3. Gas in the Abdomen, and Intestines of an Elephant.—The 
gas in the abdomen ofthis animal after death was found to be a 
mixture of carbonic acid and azotic gas, with a little sulphuretted 
hydrogen. The gas in the intestines, on the other hand, seemed 
a mixture of carbonic acid and carburetted hydrogen,—(Vauque- 
lin, Annals of Philosophy, xii. 119.) 
4. Sinovia of the Hlephant.—This liquid was examined by 
VYauquelin, who found its nature to correspond nearly with that 
