THE EESIN OE FICUS EUBIUINOSA. 
45 
we were not successful, for reasons hereinafter mentioned, in obtaining this substance 
perfectly pure. 
Sycoretin. 
Cold alcohol of moderate strength dissolves the principal part of the original resin, 
forming a light brorvui solution, which on precipitation with water, or the separation of 
the alcohol by means of distillation, furnishes the sycoretin. The alcoholic solution of 
this resin is perfectly neutral, and scarcely any precipitate is caused in it on the addition 
of an alcoholic solution of acetate of lead or acetate of copper. This behaviour indi- 
cated at once that no acid compounds were present, and that this resin is perfectly 
neutral. The minute precipitate which formed we ascertained to be tannate of lead, 
the source of the tannic acid being probably the bark which contaminated the resin. 
This resin was purified by redissohing it in alcohol, and in order to remove the small 
amount of colour the solution was treated with animal charcoal, but this had no effect. 
No better result was obtained when a small quantity of acetate of lead was introduced 
in the solution, and a basic lead salt thrown down with ammonia. We afterwards found 
that the colour could be gradually removed by repeated precipitation of the resin from 
its alcoholic solution by means of water. 
The decolorized resin was now redissolved in a just- sufficient quantity of alcohol, and 
the solution left for some time in a cool place, when a small amount of crystalline sub- 
stance was deposited, which was filtered off. By the addition of a little water a small 
quantity of sycoretin was then thrown down, in order to carry down the last traces of 
the less soluble crystalline compound, in case any were still present. After this treat- 
ment the solution was again allowed to stand for some time, but no further precipitate 
was formed. The clear solution was now partly precipitated with water, and the pre- 
cipitate removed after it had subsided, heat being used to facilitate the subsidence of 
the sycoretin by causing the precipitate to agglutinate into one mass. That part of the 
resin remaining in solution was afterwards thrown do'wn with water and collected sepa- 
rately. 
The two different’ lots of resin thus obtained had the same appearance ; both were 
brittle, but only the last became sticky when masticated, and tasted like the original 
resin. Both products were powdered and kept for some time in vacuo over sulphuric 
acid, in order to remove all traces of any adhering Avater or alcohol. 
The analysis of the first precipitated part (A) gave the following numbers ; — 
0‘2056 grm. of substance gave 0-5625 grm. carbonic acid, and 0-1870 grm. water. 
The analysis of the portion last thrown down (B) gave the following : — 
0-1733 grm. of substance gave 0-4950 grm. carbonic acid, and 0-1550 grm. water. 
The foregoing results give the following per-centages : — 
A. 
74-65 
10-11 
MDCCCLX. 
Carbon . 
Hydrogen 
H 
B. 
77-89 
9-94 
