252 
ON COLCHICIA. 
■y^o cm. In making the following experiments, a sufficient amount of the reagent was 
added to enough distilled water to make 1 fluid ounce, and the solution of colchicia was 
carefully dropped in until, after stirring, a permanent turbidity was observable. Under 
these circumstances it was required of 
Mayer’s iodohydrargyrate of potassium 15 drops—turbidity quite distinct. 
Sonnenschein’s phosphomolybdic acid . 20 drops—turbidity distinct. 
Tannic acid.100 drops—turbidity scarcely observable. 
It follows from this that the following amounts of colchicia may be detected by 
Mayer’s test . . . *01645 grain, or one part in 27700 water.* 
Sonnenschein’s test . *02193 „ „ 20778 „ 
Tannic acid . . . *10965 „ „ 4156 „ 
Solutions of colchicia in water acidulated with sulphuric and with muriatic acid were 
evaporated, and three times' taken up by water and again evaporated ; the aqueous so¬ 
lutions were finally filtered from the separated resin, and the filtrate slowly evaporated 
with an excess of carbonate of lead, the residue then treated with strong alcohol and 
slowly evaporated. Colchiceine was obtained in yellowish crystals, which were free from 
acid and lead. Dissolved in water it still yields precipitates with tannin, phosphomo¬ 
lybdic acid and iodohydrargyrate of potassium ; but neither in solution nor in substance 
does it produce any reaction on red or blue litmus-paper. Rendered faintly alkaline by 
ammonia, the solution occasions precipitates with the soluble salts of barium, calcium, 
and lead, which are soluble in dilute nitric acid. Towards acids it behaves similar to 
colchicia. 
The resinous matter remaining on the filter when colchiceine is filtered off, was dis¬ 
solved in alcohol, and the solution evaporated ; an amorphous, brown-greenish mass was 
left, in which alcoholic solution has a decided acid reaction. Concentrated nitric acid 
dissolves it with an evanescent yellow colour ; on the addition of sulphuric acid the so¬ 
lution takes place with a purplish-brown, rapidly disappearing; pure sulphuric acid 
dissolves it with a brown colour. 
Having looked in vain in every portion of the decomposed colchicia for glucose, or a 
compound which would reduce an alkaline solution of copper, the observations of Ober- 
lin, Ludwig, and Hiibler, are confirmed. 
Taking all these results together, no doubt colchicia must be looked upon as an alka¬ 
loid, the salts of which are soluble in water, but decomposed with the formation of 
colchiceine, on keeping them in solution as well as on evaporating them. The crystal¬ 
line mass, obtained by Mr. Carter on evaporating sulphate of colchicia, was undoubtedly 
colchiceine. 
Aschoff and Bley observed already that colchicia combines with bases, and that when 
it is evaporated with a solution of the carbonate of an alkali, the residue contains no 
carbonic acid. Hiibler makes it probable that colchiceine is formed under these circum¬ 
stances. Colchicia is a very weak base, and colchiceine, if it can be regarded as an acid, 
is certainly a weak one, and resembles the alkaloids in its behaviour to some reagents. 
If colchicia and colchiceine have the same composition, the acid resin formed together 
with the latter can scarcely be different. 
In preparing colchicia, the action of alkalies and acids, particularly when heat is ap¬ 
plied, must be avoided. 
Regarding the officinal preparations of colchicum, requiring the application of heat, 
the two fluid extracts must contain colchicia in its natural state of combination ; ex- 
tractum colchici aceticum, however, contains colchiceine. It would be interesting to 
ascertain how long colchicia is found in the officinal wines before it is partly or entirely 
converted into colchiceine ; the similarity of their reactions will increase the difficulties 
of their separation without further decomposition of the alkaloid, while it facilitates 
the discovery of colchicum in cases of poisoning. Aschoff proved its presence in the 
stomach, heart, lungs, kidneys, and blood of a cat which had been killed by 1| grains 
of colchicia.— American Journal of Pharmacy. 
7 
* One fluid ounce of water = 455*669 grains. 
