182 BACTEftlAL POlSOlfS. 



acid by sulphuric acid, the same reactions were obtained as 

 with the original extract. 



With phosphomolybdic acid, phosphotuugstic acid, potas- 

 sio-bismuthic iodide, potassio-mercuric iodide, iodine in 

 potassium iodide, tannic acid and gold chloride, this sub- 

 stance gave the same reactions which were obtained by 

 parallel experiments with genuine colchicine; thus, the 

 tannic acid precipitates were both soluble in alcohol, and. 

 the precipitates with phosphomolybdic- acid in both cases 

 became blue on the addition of ammonium hydrate. 



Concentrated sulphuric and dilute nitric and hydrochloric 

 acids dissolved the supposed colchicine with yellow colora- 

 tion. Strong nitric acid (1.4 sp. gr.) colored the substance 

 dirty red, scarcely to be called a violet. When the sub- 

 stance was purified as much as possible, this color became 

 a beautiful carmine-red. The addition of water changed 

 the red into yellow, and caustic soda produced a dark, dirty 

 orange. 



In general, in the above-mentioned reactions, the putre- 

 factive product agreed with the real colchicine, but the 

 former gave precipitates with picric acid and platinum 

 chloride, while the latter gives no precipitates with these 

 reagents. 



In 1886, Zeisel proposed the following test for colchi- 

 cine : When a hydrochloric acid solution of the aliialoid is 

 boiled with ferric chloride, it becomes green, sometimes 

 dark-green and cloudy. Now, if the fluid be agitated with 

 chloroform, the chloroform will sink, taking up the coloring 

 matter, and appearing brownish, granite-red or dark, and 

 the supernatant fluid clears up without becoming wholly 

 colorless. 



Batjmeet applied this test to both colchicine and the 

 putrefactive product. To from two to five cubic centi- 

 metres of the suspected solution in a test-tube, he added 

 from five to ten drops of strong hydrochloric acid and 

 from four to six drops of a ten per cent, solution of ferric 

 chloride, then heated the mixture directly over a small 

 flame until it was evaporated to half its volume or less. In 

 the presence of one milligramme of colchicine the originally 



