338 y^"^^ OLEAGINOUS COMFOUNB. 



which was separated in small flakes on the addition of water; 

 while the acid remained in the retort, and precipitated on 

 cooling in a crystallized state. 

 Properties of Properties of the lower stratum, or oleaginous com- 

 the lower. pound. — It was of a bright yellow colour, depending, as I 

 have before remarked, on a quantity of resin, which th« 

 acid contained. It is strongly acid, and has a pleasant aro- 

 matic smell. When a few drops were put upon a spatula, 

 and exposed to the heat of about 250", it Avas rapidly vola- 

 talized ; and on taking it away, the remaining portion crys- 

 talized upon the spatula, like rays diverging from a centre. 

 These crystals were dissolved in alcohol, which then red- 

 dened vegetable blues. When this peculiar compound wai 

 immersed in cold water, it was immediately decomposed, th« 

 alcohol entered into chemical combination with the water; 

 the benzoic acid was precipitated in small shining crystals, 

 and the camphor remained on the surface of the fluid. This 

 then is sufiiciently evident, to elucidate that water, although 

 necessary to its formation, will not preserve it when formed, 

 without the necessary admixture of a definite quantity of 

 alcohol. 



Boiling water readily dissolves it, and precipitates on 

 cooling about — 1*^^ of the acid, in small flaky crystals ; 

 ' while the camphor is principally separated, and rises to the 

 surface of the fluid, leaving, however, a small portion in 

 solution. It is very soluble in alcohol , and, if dissolved in 

 lufficient quantity, may be recondensed into the original 

 compound. When mixed with a solution of the sub- 

 carbonate of potash it was decomposed, a benzoate of pot- 

 ash was formed, and a quantity of carbonic acid gas was 

 evolved; while the camphor, the other constituent, was 

 liberated, and floated on the surface of the fluid. In order, 

 therefore, to obtain a quantity of the benzoic acid in a pure 

 state, the camphor was separated from this solution by 

 passing it through a filter, and obtaining the solution of 

 benzoate of potash in the receiver. To a portion of the 

 solution thus collected, sulphuric acid was added to satura- 

 tion, which, from its greater affinity, formed a sulphate of 

 potash, to the exclusion of the benzoic acid, both of which, 

 - iiowever, wer« mechanically combined, and formed a white 

 u; preci;?itate : 



