ON ARNICINA. 
16 ? 
investigations in every direction, hoping thereby to obtain 
similar results from other bodies whose activity on the animal 
economy had been clearly ascertained. After a time, richly re- 
warded were their foresight and zeal ; for Gomes discovered 
cinchonine in 1811 ; Pelletier and Caventou isolated emetine 
in 1817, and quinine in 1820; Meissner obtained veratrine in 
1818 ; and Pelletier and Caventou discovered strychnine in the 
same year. Several other organic bases were discovered by 
these and other pharmaceutists about and during the same 
periods. 
After this time the progress of the discovery of the alkaloids 
comparatively ceased, — for the simple reason, that the methods by 
which the above bases were eliminated failed when applied to 
the extraction of similar bodies from such plants as conium, 
tobacco, hyoscyamus, &c. Pharmaceutists then properly turned 
their attention to devising new methods for the separation of 
organic bases, reasoning correctly that the plants from which 
they failed to obtain them might, nevertheless, contain them ; 
but that the alkaloids sought for might possess such different 
properties from those already known as to render their elimi- 
nation by the usual methods impossible. 
They succeeded in devising new methods, and these new 
methods were eminently prolific in important results; for we are 
indebted to them for a number of alkaloids possessing such 
active powers on the animal economy as to be unsurpassed by 
any substances before known, either of organic or inorganic 
origin. 
It is customary with the authors of works on systematic 
chemistry to divide the alkaloids into two classes, the non- 
volatile and the volatile, and, in pursuance of this arrangement, 
to give two general methods for extracting them. The first 
consists in treating the substance containing an organic base 
with a dilute mineral acid, for the purpose of dissolving it there- 
out; the base is then precipitated from this solution by a caustic 
alkali. This process is suitable when the base is not decom- 
posable by alkalies or not very soluble in water, and is best 
adapted for those which are non-volatile. The second method 
directs the substance to be distilled with a weak solution of a 
caustic alkali, and is available when the base is volatile and not 
readily decomposable by caustic alkalies. 
In confining themselves to this limited classification, these 
writers have left unprovided for a great number of alkaloids, 
which admit, and are perhaps not unworthy, of forming a class, 
and consequently a method indicated by which they may be, in 
general, recognized and eliminated. 
The alkaloids alluded to are those which are destroyed by the 
