1887.] Professor Fraser on Chemistry of Strophanthin. 371 
tion of the results of this examination, I propose now to mention 
only a few of these results in a brief form. 
The active principle, to which I have given the name Strophan- 
thin, occurs most abundantly in the seeds. By a very simple 
process, consisting essentially of the separation of oil by means of 
ether from the alcoholic extract, I obtained some years ago a crys- 
talline body having great pharmacological activity, and possessing 
the characteristics of a glucoside. In subsequent experiments, 
however, although the same process was followed, a well-marked 
crystalline product was not always obtained, and it soon became 
evident that this difference was due to some difference in the con- 
dition of the seeds which had been operated with. Thus, from seeds 
collected by the late Bishop Mackenzie more than twenty years ago, 
and also from seeds sent to me by Mr Buchanan of Blantyre, East 
Africa, in 1881, I had no difficulty in separating an active principle 
in the form of well-marked minute crystals ; but from seeds ob- 
tained from Mr Buchanan in 1885, and also from seeds liberally 
placed at my disposal by Mr Moir and by Messrs Burroughs, Well- 
come & Co. last year, I failed to obtain an equally definite crystalline 
body. I also found that the body obtained by the process formerly 
described, whether in well-defined crystals or not, was resolvable 
by acetate of lead into at least two bodies, one of which is an 
extremely active glucoside, and the other an acid, for which I would 
suggest the name kombic acid. It having become apparent, there- 
fore, that the strophanthin first described is not a simple substance, 
attempts were made to improve the process so as to separate 
strophanthin in a more pure form than I had originally succeeded 
in doing. The result of these attempts has been the adoption of a 
process whose essential steps are the following : — 
Starting with the product obtained by the earlier process, it is 
dissolved in water, tannic acid is added to the solution, the tannate 
is digested with recently precipitated oxide of lead, and then 
extracted with rectified and proof spirit. This extract is dissolved 
in a small quantity of rectified spirit, and the solution is pre- 
cipitated by ether. The precipitate is finally dissolved in weak 
alcohol, and through this solution carbonic acid is passed for several 
hours, by which means lead is completely got rid of. After filtra- 
tion the solution is evaporated at a low temperature, and the 
