DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 995 



Analysis No. 7 . 



8000 grains of seeds from Buchanan, 1885 — 



Rectified spirit extract (12 of rectified spirit to 1 of seeds), 70T655 grains, = 8-77 per cent. 

 Ethyl ether extract, 1013-416 grains, =12-667 „ 



In this analysis the extraction of the seeds by rectified spirit had been effected by two 



successive percolations. The first percolate of 1*3 of rectified spirit to 1 of seeds yielded — 



Rectified spirit extract, 388-755 grains, ..... = 4"859 per cent, of seeds. 

 Ethyl ether extract, 260-65 grains, = 3'258 „ 



The second percolate of 10*7 of rectified spirit to 1 of seeds yielded — 



Rectified spirit extract, 312-9 grains, ...... = 3-911 per cent, of seeds. 



Ethyl ether extract, 752-765 grains, ...... =9*409 „ 



Analysis No. 8. 



1500 grains of seeds from Buchanan, 1885 — 



Rectified spirit extract (8 of rectified spirit to 1 of seeds), 114-66 grains, = 7 - 664 per cent. 



Ethyl ether extract, 499 grains, = 33-266 „ 



In analyses 3, 4, and 5 the extraction with ether was continued until a colourless 

 percolate had been obtained, and the subsequent extraction with spirit was continued 

 until the percolate was free, or almost free, from bitterness. In analyses 6, 7, and 8, the 

 percolation with spirit was continued until the tinctures were colourless and free, or almost 

 free, from bitterness. 



In the analyses in which extraction with ether preceded extraction with rectified spirit, 

 the results were fairly concordant. They show that the ether extract, consisting mainly 

 of fat, with a small quantity of chlorophyll and of resin, amounts to about 34 per cent., 

 and that the alcohol extract, containing the active principle, amounts to about 9 '5 per 

 cent, of the seeds. 



When the seeds were first extracted with rectified spirit, and the substances in the 

 extract soluble in ether then removed from it, the results varied considerably. This was 

 specially apparent in the case of the ether product, but it was also observed in the alcohol 

 extract from which the substances soluble in ether had been removed. As will, however, 

 be pointed out, in so far as the latter product is concerned, these differences are of com- 

 paratively little importance as indications of corresponding variations in the actual 

 quantities of active principle present in the seeds. 



Ether Extract. 



The ether extract, whether obtained with ethyl or petroleum ether, consists mainly 

 of a liquid fat or oil containing chlorophyll and other colouring matters ; and when 

 obtained with ethyl ether, of a small quantity also of resin. It gives a permanent 

 translucent stain to paper. Its colour varies considerably, the lightest coloured specimens 



VOL. XXXV. PART IV. (NO. 21). 7 M 



