1000 DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 



the latter become much darker in colour, they lose their opacity and brittleness, and 

 acquire a plastic amorphous character and a dark reddish-brown colour. These changes 

 occur independently of exposure, as they have been observed with extracts protected 

 from the effects of exposure by being placed as soon as dried in well-stoppered bottles. 



The impure strophanthin, precipitated by ether from an alcoholic solution of extract, is 

 also a much purer substance when it is derived from the first percolate than when it is 

 derived from subsequent percolates. In the former case, it is pale, brittle, crystalline, and 

 opaque, and it retains these characters for an indefinite period ; while in the latter case, it 

 is, from the first, translucent and of a brownish-yellow colour, and if dried so as to 

 admit of being reduced to a powder, it soon afterwards becomes an adherent homogeneous 

 mass of dark colour. 



Analyses of the Testa and of the Cotyledons and Embryos of the Seeds. 



The next analyses were made in order to ascertain the quantity of each of the above 

 ingredients present in the testa and in the combined cotyledons and embryos, respectively, 

 and especially to ascertain whether the former or the latter contains the largest quantity 

 of active principle. When the testa was carefully separated from the rest of the seeds 

 it was found, in 119 "48 grains of seeds, that the testa weighed 52*6 grains, or 44 per cent., 

 and the combined cotyledons and embryos, 66*88 grains, or 55*97 per cent., of the seeds. 



Analysis No. 13. 



52*6 grains of testa yielded — 



Anhydrous ether extract (28 : 1) 9-58 grains = 18*212 per cent, of testa, or 8 - 016 per cent, of seeds. 

 Rectified spirit extract (20 : 1) 4-58 grains = 8-707 „ „ or 4-873 „ „ 



66*75 grains of cotyledons and embryos yielded — 



Anhydrous ether extract (26 : 1) 31 - 15 grains = 46 - 666 per cent, of cotyledons and embryos, or 26-118 



per cent, of seeds. 

 Rectified spirit extract (20:1) 4-865 grains = 7*288 per cent, of cotyledons and embryos, or 4 - 07 



per cent, of seeds. „ 



The testa therefore yielded a much smaller quantity of ether extract, but a somewhat 

 larger quantity of spirit extract, than the combined cotyledons and embryos. The ether 

 extract derived from the testa was, however, a very different substance from that derived 

 from the cotyledons and embryos. The former was of a dark greenish-brown colour, 

 and not quite clear ; the latter was of a very pale yellow colour, with a tinge of green, 

 and at a temperature of 60° F., the greater part of it was perfectly clear and translucent, 

 there being only a small whitish sediment. 



The alcohol extracts also possessed marked differences in character and composition. 

 That from the testa, when perfectly dry, was yellowish-brown in colour, semi-translucent, 

 only partly brittle, and faintly aromatic ; but in a short time, even in a stoppered bottle, 

 it became dark reddish-brown, adhesive, and soft. The alcohol extract from the coty- 



