998 DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 



analysis also shows that the quantity of non-crystalline substances varies in different 

 extracts, and that one important cause of this variation is the amount of spirit percolated 

 through the seeds in the preparation of the extract. 



Composition of the Alcoholic Extract. — On adding to the dried alcohol extract a 

 small quantity of rectified spirit, the extract does not entirely dissolve, but a residue 

 remains, which is insoluble in a moderate quantity of rectified spirit. When the clear 

 alcohol solution thus obtained is mixed with ether, it becomes densely opalescent, but in 

 a short time the opalescence clears away, and a translucent amorphous and intensely 

 bitter deposit occurs. The decanted and usually clear alcohol-ether solution also yields 

 a residue when distilled and evaporated. 



The first of these products is freely soluble in water, forming a mucilaginous solution, 

 which reduces Fehling's solution after it has been digested for some hours with a little 

 dilute sulphuric acid. The second product agrees with the active principle, for which I 

 have proposed the name, strophanthin, in the chemical and pharmacological characters 

 afterwards described. The third product is insoluble in water and in acids, soluble in 

 rectified spirit and in dilute alkalis, and precipitated from the latter solution by acids, and 

 it is, therefore, a resin. 



The quantity of each of these products, in two out of several extracts that have been 

 analysed, is stated in Analysis 9 and 11 below — 



Analysis No. 9. 



Alcohol Extract of Analysis No. 1 (p. 993). — Total alcohol extract, 8'94 per cent, of 



seeds. 



Impure strophanthin, ....... 63-367 per cent, of alcohol extract. 



Mucilage, 16-275 „ 



Resin, 14542 „ „ 



94-184 



The total extract (8'94 per cent, of seeds) was, however, the sum total of the extracts 

 of three successive percolations of the same seeds ; the first having been obtained by a 

 percolation of 10 parts of rectified spirit to 1 part of seeds, the second by a subsequent 

 percolation of 5 parts of rectified spirit to 1 of the same seeds, and the third by a 

 subsequent percolation of 5 of spirit to 1 of seeds. It is interesting to note the total 

 quantity of alcoholic extract obtained from each of these percolates, and the composition 

 of each extract. 



Analysis No. 10. 





1st Percolate, 10 : 1. 



2nd Percolate, 



5 :1. 



3rd Percolate, 



5:1. 











Total Extract, 7 "9 



Total Extract, 



674 



Total Extract, 



0-37 











per cent, of Seeds. 



per cent, of Seeds. 



per cent, of Seeds. 









Impure strophanthin, 



68-16 



27-44 





25-67 





pel 



cent. 



of extract. 



Mucilage, 



12-27 



42-28 





52-7 







)> 



>) 



Resin, 



13-79 

 94-22 



23-36 





14-18 







3) 



» 





9308 



92-12 



