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X. 



'I'HE TAXTNE IN IRISH YEW, 

 TAXUS BACCATA var. FASTIGIATA. 



By RTCHAED J. MOSS, F.I.C., F.C.S. 



Read February 23. Ordered for Publication March 9. Published April 30, 1909. 



Though the poisonous nature of Yew has been known for many centuries, 

 it is only quite recently that the extraction of the supposed poisonous principle 

 taxine has been carefully studied. 



In a paper on taxine, by T. E. Thorpe, c.b., f.r.s., and George Stubbs,' 

 the literature of the subject is reviewed ; and a simple method for the extraction 

 of taxine from the leaves is described. The authors show that taxine readily 

 undergoes change when warmed on the water-bath with dilute acid. All 

 tlie earlier investigations involving the evaporation of acid- solutions in the 

 water-bath must have yielded erroneous results. 



In the method of Thorpe and Stubbs the air-dried leaves are powdered, 

 and then extracted at the ordinary temperature with 1 per cent, sulphuric 

 acid. The extract is rendered alkaline with ammonia, and shaken with 

 ether. The ethereal solution is then shaken with dilute hydrochloric acid; and 

 this operation is repeated until a colourless ethereal solution is obtained. 

 From this the taxine is finally extracted with dilute hydrochloric acid, and 

 precipitated by ammonia. The taxine is next dissolved in ether, the ether 

 is evaporated, and the residue dried over sulphuric acid and weighed. The 

 quantitj' of alkaloid obtained in this way corresponded to 0'18 per cent, 

 of the green leaves of the male tree. Other experiments led to the separa- 

 tion of 0'12 per cent, of tlie green leaves of the female tree. As no particular 

 variety of Yew is mentioned, I presume the kind used was the common 

 Yew. 



I have applied the method to the leaves and fruit of the Irish Yew, 

 known to botanists as the Florence Court Yew, Taxus haccata var. fastlgiata; 

 and, as I obtained a much larger yield of taxine, I thought the results worth 

 placing on record. 



'Journal of the Chemical Society, Transactions, 1902, p. 874. 



