372 Proceedings of Royal Society of Edinburgh. [july 15 , 
product is dried in vacuo over sulphuric acid. In the process of 
drying, it first assumes a translucent, gummy appearance, and then 
becomes opaque and white. 
Strophanthin thus obtained is imperfectly crystalline, neutral or 
faintly acid in reaction, intensely hitter, freely soluble in water, less 
so in rectified spirit, and practically insoluble in ether and chloro- 
form. It hums without residue, and it does not contain nitrogen. 
When subjected to ultimate analysis its percentage composition, 
taking, for the sake of brevity, the average of several closely 
agreeing combustions, was found to he — 
Carbon, 55 ’976. 
Hydrogen, 7 ‘75 4. 
Oxygen, 36 ‘283. 
This percentage composition fairly corresponds with the formula, 
The effects of a number of reagents upon it have been deter- 
mined. In the meantime the following may be stated : — Strong 
sulphuric acid produces a bright green colour, which soon becomes 
greenish yellow and brown ; sulphuric acid and bichromate of 
potash, in addition to the changes produced by sulphuric acid, a 
blue colour ; phospho-molybdic acid, after contact for a few hours, 
a bluish green, which, on the addition of a few drops of water, 
becomes pure blue ; * nitric or hydrochloric acid, a yellowish brown ; 
and caustic potash, ammonia, and other alkalies a faint yellow. 
With a 1 per cent, solution in water, phospho-molybdic acid causes, 
somewhat slowly, a bright green colour, which after prolonged con- 
tact becomes greenish blue ; * nitrate of silver, a reddish brown 
colour, and a slight dark precipitate ; caustic potash and other 
alkalies, a very faint yellow ; dilute sulphuric acid, a faint white 
opalescence ; and tannic acid, an abundant white precipitate, soluble 
in excess both _ of strophanthin and of tannic acid. The solution, 
tested at the ordinary temperature, is not changed in appearance by 
acetate or subacetate of lead, perchloride of platinum, chloride of 
gold, perchloride of iron, perchloride of iron and sulphuric acid, 
perchloride of mercury, sulphate of copper, bichromate of potassium, 
* Since this paper was communicated, I have found that the blue colour 
may he almost instantaneously produced by adding an alkali, such as solution 
of potash, after the addition of the phospho-molybdic acid. 
