1010 DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 



in order to remove traces of lead. The solution was then evaporated to dryness, and the 

 residue dissolved in rectified spirit, and, after filtration, ether was added to the solution 

 to precipitate the active principle. The precipitate was dissolved in absolute alcohol, which 

 usually left a further slight sediment, and the clear alcoholic solution was finally dried by 

 spontaneous evaporation, and by being placed in a partial vacuum over sulphuric acid. 



By this process, about 65 per cent, of the active principle, strophanthin, was usually 

 obtained from the extract. This quantity, undoubtedly, does not represent the whole of 

 the active principle present in the extract ; but the result otherwise is satisfactory, in so 

 far as the quality of the product is concerned. 



Characters. — Strophanthin thus obtained is a colourless, opaque, and brittle sub- 

 stance, having an appearance suggestive of a crystalline body, but exhibiting no crystals 

 to the naked eye. Under the microscope, however, it is found to consist of minute 

 irregular crystalline plates, whose appearance is illustrated in Plate VII. fig. 9. 



When ether is added to very dilute alcoholic solutions of it, and the faintly turbid 

 mixture is put aside in a stoppered bottle for a few days, beautiful stellar groups of 

 colourless and transparent crystals frequently form on the sides and at the bottom of 

 the bottle. Some of these groups, as seen with a lens magnifying about six times, have 

 been represented in Plate VII. fig. 7. 



Strophanthin is very freely soluble in water and in rectified spirit, losing its opacity 

 when a very small quantity of either solvent is added to it, and becoming a viscous, 

 clear, and faintly yellow solution on further minute additions. It is soluble in 55 parts 

 of absolute alcohol (sp. gr. 796), in 300 parts of acetone, and in 1000 parts of amyl 

 alcohol (sp. gr. *820). It is almost insoluble in chloroform (sp. gr. 1'497), in absolute 

 (sp. gr. '723) and common (sp. gr. 730) ethyl ether, in petroleum ether boiling below 

 120° F., and in bisulphide of carbon.* Glycerine (sp. gr. 1*26) dissolves it freely; but 

 when small quantities are placed in strophanthus oil and in olive oil, respectively, they 

 remain unchanged for several months, although, afterwards, the particles appear to dis- 

 solve very slowly. 



Solutions in rectified spirit and in amyl alcohol are precipitated by the addition of 

 chloroform, absolute or common ethyl ether, petroleum ether, and bisulphide of carbon. 

 A solution in absolute alcohol is precipitated by ethyl and by petroleum ether, and is 

 rendered slightly turbid by bisulphide of carbon ; but neither chloroform nor acetone 

 produce any change in the appearance of the solution. A solution in acetone is precipi- 

 tated by ethyl ether, petroleum ether, chloroform, and bisulphide of carbon, but not by 

 absolute alcohol nor by amyl alcohol. 



Strophanthin is intensely bitter. When dissolved in distilled water, the bitterness is 

 slightly appreciable in a solution of 1 part in 300,000. Its solution in water or rectified 

 spirit is acid in reaction. When a dilute solution in water is shaken, a persistent froth 

 is produced. Solutions in ordinary or in distilled water soon lose their perfect trans- 



* In the experiments that were made, chloroform dissolved 1 part in 10,000, and absolute and common ethyl ether, 

 petroleum ether, and bisulphide of carbon about 1 part in 20,000. 



