ON THE SUBLIMATION OF THE ALKALOIDS. 
197 
brought forward as affecting the general question of the sublimates of the alka¬ 
loids. The sublimation of strychnine itself, like that of morphine, veratrine, 
aconitine, and other poisonous alkaloids, must form the subject of careful and 
multiplied experiments, not limited to the procuring of sublimates under cir¬ 
cumstances analogous to those which present themselves in actual practice, but 
identical with them. These poisons must be extracted from organic liquids, or 
from the bodies of animals ; and the precise value of the method of sublimation 
must ultimately be tested in this way. Meanwhile, this series of essays on the 
sublimation of the alkaloids as a class may now be brought to a close ; and this 
is best done by appending a series of distinct propositions founded on the facts 
already established. 
1. That the method of subliming substances in minute quantities on flat sur¬ 
faces of glass, in order to their complete examination by the microscope,—a 
method first recommended for such poisons as arsenious acid and corrosive sub¬ 
limate nearly ten years since,—may be advantageously extended to the alka¬ 
loids and other .analogous active principles, and also to many other volatile and 
decomposable matters, both vegetable and animal. 
2. That, in the case of the alkaloids and analogous active principles, the best 
form of apparatus is that which consists of a slab of white porcelain, a micro¬ 
scopic cell-glass, and a disk of window glass : the flame of the spirit-lamp to be 
cautiously applied to the porcelain, and the heat gradually increased till the 
sublimate shows itself on the disk of glass previously deprived of moisture by 
being passed through the flame. The lamp to be then withdrawn, and the pro¬ 
cess repeated, till the substance refuses to yield any further sublimate. 
3. That, in operating on deposits of the alkaloids obtained from their solu¬ 
tions, the deposits should be collected on small fragments of glass, which should 
be completely enclosed in the cell-glass, so that the deposit may be contained in 
a short, shallow tube, and be deposited on the glass disk without loss. 
4. That by this method of procedure highly characteristic results are obtain¬ 
able with a large number of substances, and notably with the alkaloids and 
analogous active principles ; these results consisting of visible changes of colour, 
consistence, and form on the heated white porcelain slab, as well as of charac¬ 
teristic microscopic appearances in the sublimate itself, both before, during, 
and after the use of reagents. 
5. That while the alkaloids, as a class, change colour, melt, fume, and deposit 
carbon, several of the most important poisonous alkaloids yield sublimates 
which are either highly characteristic in themselves, or behave characteristically 
with reagents, or possess these two properties jointly. 
6. That the salts of the alkaloids yield sublimates. 
7. That (taking strychnine as the type of the class of alkaloids) it may be in¬ 
ferred that deposits of the alkaloids from their solutions will yield sublimates of 
characteristic forms and reactions, even when the deposit itself is amorphous 
and cannot be identified. 
8. That strychnine, and probably other alkaloids, will yield sublimates prior 
to melting, or even change of colour; so that, if the process were not carried 
out to its full extent (i. e. the deposit of carbon) and the microscopic appear¬ 
ances of the sublimate were disregarded, it would be possible to confound pow¬ 
dered strychnine with arsenious acid, corrosive sublimate, or cantharidine. 
9. That characteristic results are readily obtained with such small quantities 
as the of a grain or less of strychnine, and that sublimates consisting of 
or even as little as the tuooo^ °f a grain, are found to have characteristic 
properties when examined by the microscope, and to have equally characteristic 
reactions. Similarly minute quantities are found to suffice in the case of mor¬ 
phine and of some other alkaloids. 
10. That even those sublimates which do not possess the most distinct micro- 
