508 
SECOND REPORT — 1832 . 
At the head of this list I have placed four acids,—the croconic, 
mellitic, chloroxalic, and formic,—which are not properly of 
vegetable origin, but which, from their analogous composition, 
seem naturally to belong to this class. 
The list might have been much swelled out by inserting the 
numerous resinous substances which Unverdorben has shown 
to possess electro-negative properties ; but it would extend the 
term ‘Acid’ too widely to rank all such bodies among the acids 
properly so called. Other acid substances have also been met 
with, to which no names have yet been given: among these is 
one obtained in a crystalline form, by the action of nitric acid 
on meconine, and which, according to Pelletier, is composed of 
carbon 49*76, nitrogen 9*50, hydrogen 4*78, oxygen 85*96, or 
18 C+ 100 + 21H + 3N. 
Vegetable alkalies .—Duflos has published a series of in¬ 
teresting researches on several of the vegetable alkalies. He 
has observed that bicarbonate of potash precipitates* narcotin, 
but not morphine, and upon this property has founded a pro¬ 
cess for preparing them. He has also increased our knowledge 
regarding brucine and strychnine, and improved the process 
for extracting them from the nux vomica. He separates the 
two alkalies by digestion in absolute alcohol, which takes up 
most of the brucine, and afterwards boiling in water as long 
as a brown colour is imparted to the cold solution by a few* 
drops of fuming nitric acid. This test is so sensible, that 
water is tinged when it contains only j-gbo o^h of its weight of 
brucine f. Quinine he finds to fuse at 248° F., losing 4§ per 
cent, of water, while cinchonine requires a temperature of 329° 
F., loses nothing, and is partly sublimed into crystals resem¬ 
bling benzoic acid. 
Mode of testing Peruvian bark .—The following method for 
testing Peruvian bark, given by Duflos, is highly deserving of 
attention. A dram of the bark finely powdered is boiled for a 
few minutes with an ounce of water and half a dram of con¬ 
centrated acetic acid, the whole thrown on a filter, the residue 
washed with water, and the whole evaporated to dryness on a 
water-bath. If the mass be still acid, it is dissolved again and 
evaporated to drive off all the acetic acid, the dry mass is 
digested in absolute alcohol, the solution freed from colouring 
matter by animal charcoal, and precipitated by bichloride of 
platinum added drop by drop as long as any deposit takes 
place. The precipitate washed, dried in the air, and weighed, 
corresponds to half its weight of the vegetable alkali. The 
* Schweigger, N. Jahrbuch, i. 105—217. f Ibid. ii. p. 304. 
