Seeds of the Croton Tiglium. 65 



Having weighed a quantity of the seeds, and separated the 

 kernel from the shells, I found 100 parts contained 64 of the 

 former and 36 of the latter. Digesting a quantity of the latter 

 with alcohol a sufficient length of time, though a dark-coloured 

 tincture was obtained, on tasting it, it was possessed of no 

 acrimony whatever. It is stated, indeed, that they possess in 

 a considerable degree the peculiar property of the seeds, but in 

 the present case no such acrimony existed. The attention was 

 consequently directed solely to the kernel of the seeds. 



Taking 40 grains of the kernel, they were first reduced to a 

 paste by bruising them in a mortar, upon which alcohol being 

 poured, they were digested with a moderate heat several days. 

 The whole being poured upon a filter, the fluid parts passed 

 through, and upon the insoluble part more alcohol was poured, 

 until every thing which was soluble in that fluid was washed 

 away. The residuum was dried, and weighed 29 parts, 1 1 had 

 been dissolved ; the former tasteless, the latter resembling the 

 alcoholic solution obtained from the entire oil. The undis- 

 solved residuary matter showed evidently that it contained a 

 fixed oil, which tinged the paper in which it was dried by 

 heat. To discover the proportion in which this oil existed in 

 the kernels not soluble in alcohol, it was treated with purified 

 oil of turpentine, a substance which has not been employed 

 in chemical analysis of vegetable substances, but which in some 

 instances may be found advantageous. 



Before, however, going on to detail the action of the puri- 

 fied oil of turpentine, it is necessary to remark that, in its ordi- 

 nary state, it is not sufficiently pure to be employed for this or 

 similar purposes ; for even when recently distilled, it contains 

 a substance which, when the oil is evaporated, remains behind, 

 and would in the present instance have led to a false estimate 

 by the addition of weight to the residuary undissolved sub- 

 stance. To remove the whole of this, 1 have employed alcohol 

 to purify the oil of turpentine for medicinal use, without dimi- 

 nishing its efficacy, but greatly lessening its disagreeable taste, 

 and its injurious action upon the kidneys, as well as for chemi- 

 cal purposes. To eight parts of the oil add one part of tlie 



Vol. XIH. F 



