114 Wsivden Sd Fedler— On the Nature of the [No. 1, 



applied to the mucous membrane of the lips or tongue, the dried tubers 

 were practically inert. The alcoholic extract, as well as the extract 

 obtained by Stas's process, were without the least action on the tongue. 

 We also tried the effect of an extract obtained by cold alcohol, and in 

 which the alcohol had been driven off by spontaneous evaporation, on a 

 mouse without producing any symptoms. This extract was also without 

 physiological action on the tongue. A glycerin and an ethereal ex- 

 tract, prepared by macerating the fresh tubers in the cold with those 

 menstrua, also yielded negative results. 



We now tried the effect of distilling the fresh tubers with water. 

 The distillate had no acrid taste : it contained only traces of hydrocyanic 

 acid. The symptoms produced by the introduction of the commoner 

 varieties of arum tubers into the stomach cannot be explained by the 

 presence of hydrocyanic acid. The production of hydrocyanic acid on the 

 distillation of organic vegetable matter with water is by no means rare : 

 ordinary linseed meal indeed yields traces of that acid on distillation 

 with water. It is possible, however, that certain varieties of arum may 

 contain a large amount of prussic acid, as for example the A. seguinum 

 of the West Indies, which is stated to furnish a juice, two drachms of 

 which has proved fatal in a few hours.* The tubers left in the retort 

 after distillation with water were still physiologically active, indicating 

 that the active principle was not dissipated by mere boiling with Avater. 

 Natives in using arum for culinary purposes frequently add an acid 

 vegetable, or fruit, such as tamarind. We tried the action of certain 

 acids on the fresh tubers, and ascertained that boiling with water 

 acidulated with hydrochloric acid for a very short period rendered the 

 tubers quite inert, when a fragment was applied to the tongue. Dilute 

 nitric acid also acted in a similar manner. The action of acetic acid on 

 the other hand was very much feebler, and the acid had to be stronger in 

 order to produce any decided diminution in activity. So far, our experi- 

 ments had been in the highest degree unsatisfactory ; as far as we were 

 able to jndge from the evidence at our disposal, there could be no reason 

 to doubt that the arums as a family did contain a principle capable of 

 inducing toxic symptoms when introduced into the system. Most of 

 the works we had consulted ascribed the poisonous effects to a volatile 

 principle. Our experiments indicated that, while drying the tubers 

 without artificial heat deprived them practically of all activity, exposing 

 them to the temperature of boiling water for at least half an hour 

 at the most only very slightly diminished their activity. As far as we 

 were aware, there was no toxic principle known which exhibited similar 

 reactions with reagents. We again tried the effect of the fresh tubers 

 * Woodman and Tidy's "Forensic Medicine." 



