d Home to the use of the drug in gout.

For medical purposes the corm should be collected in the early summer
and, after the outer coat has been removed, should be sliced and dried
at a temperature of 130 deg. to 150 deg. F.

The chief constituents of colchicum are two alkaloids, _colchicine_ and
_veratrine_. Colchicine is the active principle and may be given in full
form in doses of 1/32 to 1/16 grain. It is a yellow, micro-crystalline
powder, soluble in water, alcohol and chloroform, and forming readily
decomposed salts with acids. It is the methyl ester of a neutral body
_colchicein_, which may be obtained in white acicular crystals.

The official dose of powdered colchicum is 2 to 5 grains, which may be
given in a cachet. The British Pharmacopoeia contains (1) an extract of
the fresh corm, having doses of 1/4 to 1 grain, and (2) the _Vinum
Colchici_, made by treating the dried corm with sherry and given in
doses of 10 to 30 minims. This latter is the preparation still most
generally used, though the presence of veratrine both in the corm and
the seeds renders the use of colchicine itself theoretically preferable.
The dried ripe seeds of this plant are also used in medicine. They are
exceedingly hard and difficult to pulverize, odourless, bitter and
readily confused with black mustard seeds. They contain a volatile oil
which does not occur in the corm, and their proportion of colchicine is
higher, for which reason the _Tinctura Colchici Seminum_--dose 5 to 15
minims--is preferable to the wine prepared from the corm. At present
this otherwise excellent preparation is not standardized, but the
suggestion has been made that it should be standardized to contain 0.1%
of colchicine. The salicylate of colchicine is stable in water and may
be given in doses of about one-thirtieth of a grain. It is often known
as Colchi-Sal.

_Pharmacology._--Colchicum or colchicine, when applied to the skin, acts
as a powerful irritant, causing local pain and congestion. When inhaled,
the powder causes violent sneezing, similar to that produced by
veratrine itself, which is, as already stated, a constituent of the
corm. Taken internally, colchicum or colchicine markedly increases the
amount of bile poured into the alimentary canal, being amongst the most
powerful of known cholagogues. Though this action doubtless contributes
to its remarkable therapeutic power, it is very far from being an
adequate explanation of the virtues of the drug