146 
DK. JOHN STENHOUSE ON VEGETABLE PRODUCTS FROM INDIA. 
When the decomposition of datiscine into datiscetine and sugar is taken into con- 
sideration, it seems probable that the formula for datiscine is — 
Datiscetine+Sugar =:Datiscine 
C30H10OJ2 - 1 -Ci 2 Hj 2 Oj 2 ~C 42 H22 O24. 
That formula requires 
€ 42=252 54-08 
H 22 = 22 4-72 
024=192 41*20 
If the formula C 42 H 22 O 24 be correct, the decomposition of datiscine would be 
analogous to salicine, which, when treated with dilute acid, gives 
Salicine =Sugar -fSalicetine 
€25 Oh=C ,2 H ,2 0.2+C,4 He O 2 ; 
whilst when treated with emulsine, 
Salicine = Sugar -{-Saligenine— 2 HO. 
C 26 H,s 0,4=C,2 H 42 0.2+Ch Hs O 4 - 2 HO. 
The above formula for datiscine is confirmed by the following determinations of 
sugar formed by treating a weighed quantity of datiscine with dilute sulphuric acid. 
The quantity of sugar produced was estimated by Fehling’s method with a standard 
solution of sulphate of copper. Four determinations made in this way gave the 
following quantities of sugar for 100 parts of dry datiscine ; — 
I. 41*6 
II. 39-5 
III. 39*3 
IV. 37 * 8 . 
The calculation for the formula C 42 H 22 O 24 requires 38'6 per cent, of sugar. 
An attempt was made to confirm these determinations by the direct estimation of 
the datiscetine formed during the decomposition of a given weight of datiscine by 
dilute sulphuric acid. The numbers obtained, however, during different experiments 
did not correspond with each other, and were all much lower than theory required. 
This however is not to be wondered at, as the datiscetine, though very differently 
soluble, is by no means absolutely insoluble in water. Dilute hydrochloric acid was 
found, like sulphuric acid, to decompose the datiscine into sugar and datiscetine, 
and even 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 shown by previous experiments, and analysis No. 8, that 
datiscine may be dissolved in cold solutions of potash without decomposition. When 
boiled, however, with a concentrated potash lye for some time, decomposition takes 
place, and the precipitate, thrown down by the addition of an acid, has all the pro- 
perties of datiscetine. In this respect, therefore, datiscine agrees with tannin and 
