DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 1017 



Still, these experiments, and indeed all the experiments in which strophanthin was 

 shown to be decomposed by acids, render it not only of interest but probably of practical 

 importance to determine, as I propose on some early occasion to do, the pharmacological 

 action of strophanthidin itself. 



Strophanthidin. 



In the meantime, in addition to those physical and chemical characters of crystalline 

 strophanthidin that have incidentally been mentioned, it may be added that it has an 

 intensely bitter taste and a neutral reaction ; that it is slightly soluble in cold water, 

 moderately soluble in cold rectified spirit, chloroform, and amyl alcohol, and freely soluble 

 in warm rectified spirit ; that it becomes of a green colour when heated with 2 per cent, 

 sulphuric acid ; that it does not give a glucose reaction with the phenylhydrazin test, 

 nor with Fehling's solution, either before or after prolonged digestion with 2 per cent, 

 sulphuric acid between 200° and 212° F. ; and that it is extremely active as a pharma- 

 cological agent, 00025 and 000 125 grain producing death in frogs weighing 350 grains 

 and 345 grains, respectively, with symptoms closely resembling those produced by 

 strophanthin. Further, it can readily be obtained in colourless crystals by the spon- 

 taneous evaporation of a solution in rectified spirit. 



As a solution of recrystallised strophanthidin, produced by the decomposition of 

 strophanthin by sulphuric acid, remained unchanged when solution of chloride of barium 

 was added to it, strophanthidin cannot be regarded as a combination of some substance 

 present in strophanthin with the acid employed in decomposing it. 



The amorphous brown substance obtained by boiling strophanthin with moderately 

 strong acids has not been examined further than to determine that it is much less bitter 

 than either strophanthin or strophanthidin, and that it is insoluble or nearly so in water 

 and acids, and soluble in alkalies and rectified spirit. 



Kombic Acid. 



Basic and neutral acetate of lead have been enumerated among the reagents which 

 produce precipitates in solutions of the extract in water. The precipitate obtained by 

 the former reagent has not been examined. That produced by neutral acetate of lead, 

 after having been carefully washed with distilled water, was decomposed by sulphuretted 

 hydrogen, and the filtrate from lead sulphide was concentrated by evaporation at a 

 low temperature, and then dried in vacuo over sulphuric acid. There was thus obtained 

 a scaly brownish-yellow substance, representing 1*6 per cent, of the extract, of strongly 

 acid reaction, and freely soluble in water. For this acid, the name Kombic acid is 

 suggested. 



