﻿320 Transactions — Chemistry. 



of the bitter part of it, being thus shown, it naturally occurred to me that 

 this bitter might be the poisonous part of the nut. I therefore made the 

 isolation of this principle for the present my first object. 



The bitter part in question was soon found to be capable of absorption by 

 animal charcoal, and of removal therefrom by hot alcohol. I therefore took 

 advantage of this deportment to obtain it in a pure state for examination. 

 The details of this process are as follows : — 



The kernels are well crushed and triturated with successive quantities of 

 water (cold) till their bitter taste is gone. The solutions thus obtained are 

 rendered distinctly acid to the taste by acetic acid, by which the casein 

 and emulsin present are precipitated, and the filtrate therefrom agitated with 

 animal charcoal till the bitter substance is removed. The charcoal is then 

 collected and mixed with boiling alcohol, and the pure alcoholic solution of 

 the bitter substance thus obtained is allowed to remain for two or three days 

 at common temperatures, when the bitter part crystallizes out in beautifully 

 radiating acicular forms. 



The characters of these crystals are as follows : — -Intensely bitter; colour 

 white; lustre pearly; feebly acid; at 212° Pahr. melts ; gives a dark rose 

 colouration with warm sulphuric acid ; soluble in hot water, and feebly so in 

 cold water ; soluble in alcohol, also in hydrochloric and acetic acids ; soluble in 

 ammonia and potash ; insoluble in ether and chloroform ; does not give any 

 precipitate with tannic acid, nor with potasso-iodide of mercury, nor potasso- 

 sulpho-cyanide of zinc ; does not contain nitrogen. 



The evidence as submitted above shows that the priuciple is not of an 

 alkaloidal nature. 



Its deportment with sulphate of copper and potash is strikingly similar to 

 that of digitaline to the same tests. Both give green precipitates of a tint 

 very similar to arsenite of copper. This property of either of these vegetable 

 principles to give green precipitates with copper under these circumstances 

 seems characteristic of them, as, among the numerous substances the most likely 

 of any I know to give this reaction, not one has, on experiment, been ascertained 

 to deport itself in this manner. Thus either of these principles is readily 

 distinguishable in this way from picrotoxia, i-esins generally (including common 

 resin), soaps, gums, and the bitter principle of Phormiimn tenax. 



The green precipitates formed in this way by the bitter of the karaka and 

 digitaline respectively are, however, readily distinguished from each other by 

 subjecting them to a rise of temperature (120° Fahr. to 212° Fahr.) ; that 

 containing the digitaline is unaffected, while the other precijjitate speedily 

 changes its colour to yellow, the copper being reduced to the sub-oxide, as if 

 grape sugar were present. Further _, if the proportion of the karaka bitter to 

 the copper and potash is not properly adjusted, reduction commences at once. 



