( 338 ) 



grow wild in the environs of Nijmegen) appears, however, to be 

 comparatively rich in HCN-yielding material. 



If tlie leaves of this Rannncnlacens are crushed and digested with 

 water for 12 hours at 30^ — 36° a hydrogen cyanide-containing 

 distillate will be obtained on distillation. 



The distillate from 100 grams of fresh leaves collected on Sept. 11 

 in the botanical garden of the Veterinary School yielded 248,8 

 milligrs. of AgCN = 50,2 milligrs. of HCN = 0,05 per cent. A 

 volumetric experiment which show^ed 53 milligrs. of HCN confirmed 

 this result. 



A third experiment made ^vitll leaves, kindly forwarded to me 

 from the Botanical Gardens at Groningen, gave 0,06 per cent of 

 HCN in the distillate obtained from the same quantity of leaves. 



I failed to obtain any HCN from the root of the plant and 142 

 grams of the fresh stem only yielded 4,4 milligrs. of HCN. 



The leaves of Thalictrum aquilegifolium are therefore, compara- 

 tively rich in HCN-yielding material 



No HCN-containing distillate could be obtained from Thalictrum 

 flavum, Thalictrum minus and Thalictrum glaucura. 



Hydrogen cyanide could not be detected in the leaves in the free 

 slate. When fresh leaves were immersed in hot alcohol no HCN 

 could be detected in the alcoholic distillate. 



The hydrogen cyanide is formed during the digestion and is, there- 

 fore, most probably liberated from a glucoside by the action of an 

 enzyme. 



This enzyme is prol)ably closely related to emulsin. I have obtained 

 it, in an impure condition, by extracting the fi-esh, crushed leaves 

 with water, and adding to the filtrate a large amount of alcohol. 

 The precipitate so obtained was carefully dried ; it very readily 

 resolved amygdalin. 



The glucoside present in Thalictrum aquilegifolium is not identical 

 with amygdalin but is probably so with phaseolunatin isolated from 

 Phaseolus lunatus by Dunstan and Henry (Proc. Royal Soc. LXXH^ 

 482, 1903), because in the hydrogen cyanide-containing dislillate acetone 

 can be detected, but no benzaldehyde. The presence of the former was 

 shown from the iodoform-reaction with ammonia and tincture of 

 iodine and the solubility of freshly precipitated mercuric oxide in the 

 distillate. 



Owing to the small quantity of leaves at my disposal it was 

 useless to attempt the isolation of the glucoside in the pure state. I 

 intend doing so next year, and also to w^atch the development of the 

 glucoside in the plant. 



