539 



datiscine, the numbers of which shall agree with those found by 

 analysis. When, however, the decomposition of datiscine into 

 datiscetine and sugar is taken into consideration, it seems probable 

 that the formula for datiscine is 



Datiscetine + sugar = datiscine 



C 30 H 10 12 + C 12 H 12 12 = C 42 H 22 24' 



If the formula C^ H 22 O 24 be correct, the decomposition of datis- 

 cine by dilute sulphuric acid would be analogous to that of salicine 

 when treated in the same way. 



Dilute hydrochloric acid, like dilute sulphuric acid, decomposes 

 datiscine, converting it into datiscetine and sugar. On boiling an 

 aqueous solution of pure datiscine for some hours, traces of sugar 

 could be detected, thus showing that a small portion of the datiscine 

 had been decomposed. 



It has been already shown that datiscine dissolves in cold so- 

 lutions of potash without decomposition. When boiled, however, 

 with a strong solution of potash for some time, decomposition takes 

 place, and the precipitate, thrown down by the addition of an acid, 

 has all the properties of datiscetine. In this respect, therefore, 

 datiscine agrees with tannin and similar glucosides, which yield the 

 same products when acted upon by acids and alkalies. Yeast and 

 emulsine appeared to exert no action on solutions of datiscine. 



Action of Nitric Acid on Datiscine and Datiscetine. Cold nitric 

 acid of the ordinary strength acts violently upon datiscetine, brown 

 vapours are disengaged, and a resinous substance is produced, 

 which is ultimately dissolved, forming a dark red liquid, which, 

 when evaporated, yields crystals of nitropicric acid. 



Datiscine treated in the same way yields nitropicric and oxalic 

 acids. 



When datiscine is boiled with dilute nitric acid it dissolves, and 

 the solution obtained, when cooled, deposits pale yellow crystals, 

 which agree in every way with the properties ascribed to nitrosali- 

 cylic acid. 



On allowing datiscine to stand in contact with dilute nitric acid 

 in the cold it gradually dissolves, the solution, when left to eva- 

 porate in vacua, depositing a mixture of oxalic and nitropicric 

 acids. 



VOL. VII. 3 B 



