50 



Dr. H. M. Kyle. On the Action of the [June 25, 



analysis of the former given by Fliickiger no mention is made of 

 tannic acid, which in the latter is present in considerable quantity. 

 This constituent has, however, been found in other species of Euphor- 

 biacese — e.g., E. lathyris, L.,* a native of Southern Europe but natural- 

 ised in England and Scotland. The following preliminary chemical 

 examination of the Spurge was made by G. D. Lander, D.Sc, late of 

 St. Andrews University : — 



" The root-bark and stem contain a milky latex of acid reaction. 

 The root-bark is particularly rich in latex. On standing, the ex- 

 pressed latex speedily solidifies to a gum-resin. 



" Cold water forms a light-brown emulsion of characteristic odour. 

 On boiling the bark with water, a more concentrated extract, darker 

 in colour, may be got. A small quantity of a solid volatile with 

 steam was separated. This appears to be the odoriferous body. The 

 liquid condensed from the boiling water is neutral, indicating the 

 absence of volatile organic acids or alkaloids. No indication of the 

 presence of alkaloids could be got in a hydrochloric acid extract. On 

 distilling with alkali, an alkaline distillate is obtained, but this is prob- 

 ably due to ammonia. 



" The liquid obtained by extraction of the root-bark with hot water 

 was an acid emulsion of resin, in a solution containing starch, and prob- 

 ably also dextrin and gum. Much resin is left unemulsified in the 

 bark when the extraction is effected by hot water. 



" The concentrated extract gave a copious precipitate when mixed 

 with 10 volumes of absolute alcohol. This precipitate indicates the 

 presence in the extract of dissolved starch, and possibly also dextrin 

 and gum, which are probably innocuous. The alcoholic solution con- 

 tains resin associated with some gum. The water extract of stem and 

 leaves possessed the same properties." 



Inasmuch as it was found by experiments on trout that the volatile 

 substance could not account for the fatal action of the Spurge, but 

 that the acid emulsion of resin did, Dr. Lander prepared a quantity 

 of this by the alcoholic method, carefully removing the alcohol by 

 evaporation after the emulsion had been formed. This emulsion so 

 prepared had precisely the same fatal effects on trout as the freshly 

 prepared aqueous extract of the Spurge. 



Indications were obtained, however, at a later stage of the work, 

 that the Spurge-extract might still further be resolved into its com- 

 ponents, and the following examination was thereupon carried out at 

 the physiological laboratory. 



The emulsion formed by cold water is of a dirty-grey or light-brown 

 colour, with a small quantity of a powdery solid in suspension. By 

 repeated filtration this emulsion is broken up, and a clear brownish 

 solution is obtained. If the emulsion is retained in a tightly stop- 

 * Hooker, 'Flora' (1870), p. 329. 



