DR THOMAS R. FRASER ON STROPHANTI! US HISPIDUS. 997 



sparingly soluble in absolute, ethyl alcohol and in amyl alcohol, and insoluble in 

 chloroform and in ethyl and petroleum ether. The watery solution has usually a 

 distinctly acid reaction. When ether or chloroform ia added to the solution of the 

 extract in ethyl or amyl alcohol, the solution immediately becomes opalescent, and an 

 amorphous deposit is by and by formed. Occasionally, when ether is added to a very 

 dilute solution in rectified spirit, the opalescence is succeeded by the formation at the 

 sides and bottom of the vessel of groups of colourless glassy crystals, which, when 

 magnified, have the appearance represented in Plate VII. fig. 7. These crystals 

 possess the chemical and pharmacological properties, afterwards described, of the active 

 principle, strophanthin. 



In several of the processes in which the seeds were extracted with rectified spirit alone, 

 after the alcoholic extract had been concentrated to a syrupy consistence, rounded tufts 

 or nodules of crystals appeared in it. Under the microscope, these tufts or nodules were 

 found to consist of long and very slender radiating crystals. Their appearance, when 

 magnified, is shown in Plate VII. fig. 8. The crystals are intensely bitter, very soluble in 

 water and in rectified spirit, but much less so in absolute alcohol, and they are insoluble 

 in petroleum and ethyl ether and in chloroform. 



In every process in which the seeds were extracted with rectified spirit, and the con- 

 centrated extract mixed with water and shaken with successive quantities of ether, the 

 dried watery solution was found to consist largely of crystals having the above appearance 

 and characters. 



In a few of the analyses where this plan of extraction was adopted, when the extract 

 was mixed with a very small quantity of water, and then shaken with ethyl 

 ether, the ether assumed a fluorescent satiny appearance, which was found to be 

 caused by the diffusion through it of an enormous number of minute particles, which, 

 when the mixture was allowed to remain at rest for a short time, formed a deposit at the 

 bottom of the ether and therefore at the surface of the underlying strong watery solution. 

 On microscopic examination, these particles were also found to consist of minute slender 

 acicular crystals, usually united together in small bundles, and having the same general 

 characters as those represented in Plate VII. fig. 8. 



When, however, the seeds were extracted with ether previously to being extracted 

 with rectified spirit, the alcohol extract, on being concentrated, in no instance exhibited 

 to the unaided eye the formation of groups of crystals in it ; and when dried, although 

 having the same general appearance and characters as extracts obtained without previous 

 percolation of the seeds with ether, this extract, when broken down and examined under 

 the microscope, was seen to consist, not of slender acicular crystals, but of irregular crys- 

 talline plates, whose appearance was similar to that represented in Plate VII. fig. 9. 



However careful may have been the extraction with ether of the seeds or of the 

 alcoholic extract, this extract does not consist of a crystalline substance alone. The 

 crystals are mixed with, or imbedded in, other substances of non-crystalline structure, 

 whose existence is rendered clear when the extract is further analysed. The further 



