234 Mr. Frost on the Oil of Croton Tiglium. 



lowing manner, viz. : Having saturated a given quantity of alcohol 

 of the spec. grav. of S40, distilled water being 1000, 1 digested in 

 it 100 grains of the tiglium seed oil ; and then, after having shaken 

 the mixture, and allowed it to rest for a time, so that the tiglium 

 seed oil might precipitate, the supernatant liquor was poured off, 

 and the oil remaining weighed : the loss of weight, which was 

 21.5 grains, of course gives the rate per cent, of active matter to 

 a great nicety*. 



It may now be stated, that out of nearly ninety species of the 

 genus croton only one species is purgative, which is that in ques- 

 tion. I have examined the expressed oil of the seed of three 

 species of Jatropha, viz. : J. multifida, J. curcas, and J. pandurae- 

 folia; all these possess strong cathartic properties which I have no 

 doubt pervade the whole family. The fixed oil of the seed of 

 these species had nearly the same chemical habitudes as that of 

 the seed of croton tiglium. I have also found a similar principle 

 existing in the seed of several species of ricinus. The term 

 tigline has been assigned by Dr. Paris to the active principle of 

 the expressed oil of the seed of croton tiglium. 



I beg to add that the plate accompanying this paper is the only 

 correct one of the plant ever published, and which is taken from a 

 drawing in the possession of the Medico-Botanical Society. 



London, Nov. 13, 1825. 



Description of the Plate. 



a. The leaves, which are ovate, pointed, and serrate. 



b. The petioles, or leaf stalks. 



c. The glands, situated at the bases of the petioles. 



d. Spikes of female flowers. 



e. The capsule. 



/. An enlarged drawing of a male flower. 



g. The stamina detached, shewing their union by their filaments. 

 h. A female floret, shewing the calyx, germen, and three-bifid styles. 

 it An outline of the capsule, with the calyx remaining. 

 k. A tranverse section of the capsule, shewing its three cells. 

 /. A seed, shewing its form. 

 *». A section of a seed, shewing its thickness. 

 «. A seed divided longitudinally, to shew the embryo. 



* I have never been able to obtain more than 32 per cent, of active principle 

 in the best sample of the oil which I could procure. 



