CONSTITUENTS OF THE FRUIT OF ANACARDIUM. 1 37 
temperature, and forms about 10 per cent, of the mixture, 
the greater part of which consists of n crystalline substance 
which has no effect upon the skin. This latter body- 
belongs to the fatty acids, but it is not combined either with 
the oxide of lipyle or any other body occupying its place. 
I propose for this fatty acid the name of anacaj^dic acid, 
and for the active constituent that of cardol. The balsam, 
moreover, contains a small quantity of some colouring sub- 
stances, which appear to result from the decomposition of 
the cardol, and will be treated of when that substance is 
described. 
Anacardic acid. — To separate the anacardic acid from 
the cardol, the mixture, extracted with ether and washed 
with water, is dissolved in from 15 to 20 parts of alcohol, 
and the solution digested Avith recently precipitated hy- 
drated oxide of lead, which combines with the acid and the 
products of decomposition of cardol, which also appear to 
possess acid properties ; the Hquid loses its reaction upon 
blue test-paper and retains the cardol in solution. The 
precipitate is collected on a filter, and washed with strong 
alcohol until the drops falling into \vater no longer produce 
any turbidness. The le^^l salt is then mixed with water, 
decomposed with sulphuret of ammonium, and the solution 
of anacardate of ammonia decanted from the sediment of 
sulphuret of lead. The latter is washed once or twice with 
a little water, and the united liquids decomposed with 
dilute sulphuric acid, when the anarcadic acid separates in 
soft adherent masses, which soon solidify in the cold. They 
are repeatedly washed by decantation with cold water and 
dissolved in alcohol, when in general a little sulphur and 
sulphuret of lead remain. The moderately concentrated 
solution, which is still coloured, is mixed with water until 
a slight permanent turbidness is perceptible, upon which it 
is heated to boiling, 'and basic acetate of lead added by 
drops to it until the colouring substance, along with a con- 
siderable quantity of anacardic acid, subsides in the form of 
