— 163 — 



Thymus Serpyllum (thyme) has two varieties, one of which forms thymol, 

 and possesses the odour of that body, while the other contains citral and 

 possesses a corresponding odour of lemon. 



According to a communication by E. Fickenday 1 ), free hydrocyanic 

 acid to the extent of from 0,064 to 0,092% occurs in the stem of Ophio- 

 caulon cissampeloides, Hook. f. (N. O. Passifloraceae), a creeper which is common 

 and widely distributed in the virgin forests of tropical Africa. The author 

 has not been successful in isolating from the creeper a glucoside from 

 which hydrocyanic acid could be split off. 



The plant is used by the natives in fishing, in a manner similar to that 

 in which Cocculus Indicus (from Menispermum Cocculus), is used in Europe. 



Peckolt 2 ) gives particulars concerning Eriobotyra japonica, Lindl. 

 (N. O. Rosacea?) 3 ), a plant containing hydrocyanic acid, which is known in 

 Brazil as the "Canadian plum-tree". The species flourishes excellently in 

 Brazil, invariably yielding heavy crops. The fruit is very popular for eating. 

 When distilled the kernels of the new fruit were found to contain 0,016% 

 hydrocyanic acid. The flowers yielded an oil (sp. gr. 0,9998) with an odour 

 of heliotrope and parsley, and a bitter taste. The leaves contained neither 

 hydrocyanic acid nor essential oil. 



In an article on the generation of hydrocyanic acid in plants, A. Jorissen 4 ) 

 refers to the surmise expressed by Treub that hydrocyanic acid is formed 

 within the plant-organism by the assimilation of nitric acid. The probability 

 that Treub's hypothesis was correct was increased by the experiments of 

 Seyewetz and Poizat, who noticed that a large number of organic compounds 

 are oxidisable with nitric acid under formation of hydrocyanic acid. In this 

 process nitrous acid plays a leading part; for when urea (which, as is well 

 known, decomposes nitrous acid) is added, there is no formation of 

 hydrocyanic acid. These experiments were carried out under the appli- 

 cation of heat, but Jorissen found that certain bodies which occur in the 

 Vegetable Kingdom yield hydrocyanic acid with nitric acid without applied 

 heat. For instance, if morphia is dissolved in a somewhat large quantity 

 of standard nitric acid, and the solution is allowed to stand for a few days 

 at room-temperature, hydrocyanic acid is formed and can be distilled off, 

 after neutralising the nitric acid with carbonate of calcium. Its presence 

 can be shown by the ferrocyanide test. The same observation applies 

 to brucine, and especially to vanillin. In all these experiments the addition of 

 urea prevents the generation of hydrocyanic acid. Asparagin does no harm. 



*) Zeitschr. f. angew. Chem. 23 (1910), 2167. 



2 ) Berichte der deutsch. pharm. Ges. 20 (1910), 599. 



3 ) Gildemeister and Hoffmann, Die atherischen Ole, 2 nd Ed., Vol. I., p. 550. 



*) Bull, de l'Acad. roy. de Belgique 1910, No. 4, p. 224. Quoted from Journ. de pharm. 

 et chim. VII. 2 (1910), 358. 



11* 



