1004 DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 



Some interest is attached to the circumstance that when the extract has been in con- 

 tact with a dilute acid for a short time, slight and inconclusive alkaloidal reactions may- 

 be obtained with it. Thus, in a 2 per cent, watery solution, acidulated with weak 

 sulphuric acid, potassio-mercuric iodide, platinic chloride, auric chloride, and tri-iodide 

 of potassium, each produced a slight haze, becoming in a few hours a faint precipitate, 

 and metatungstate of sodium produced in a few minutes a scanty, but well-marked 

 precipitate. The solution was originally free from glucose, but was found to contain it 

 soon after the addition of the acid, and before the above reactions were obtained. 



Presence of a Glucoside in the Extract. 



The reduction of Fehling's reagent by solutions of the extract in dilute acids having 

 indicated the presence of glucose in these solutions, it became of importance to determine 

 if this glucose is usually and normally present in the extract, or is produced in it by the 

 decomposition of one or more of its constituents. 



Some alcoholic extract, prepared by percolating the seeds with ethyl ether and then 

 with rectified spirit, was dissolved in distilled water so as to constitute a 2 per cent, 

 solution. When heated with Fehling's reagent it failed to give any evidence of reduc- 

 tion. A portion of the same solution of extract was then acidified with sulphuric acid, 

 and left at the ordinary temperature. After three days, the now slightly turbid solution 

 was filtered, and after having been neutralised with carbonate of sodium it also was 

 tested with Fehling's solution, when it immediately produced a copious reduction. 



Evidence was thus obtained in an extract originally free from glucose, of a decom- 

 position having been caused by dilute acid, of which one of the products is glucose, and 

 the presence of a glucoside in the extract was accordingly indicated. 



Similar evidence was also obtained in one of the dark extracts derived from late per- 

 colates of the seeds. When dissolved in water, it failed to reduce Fehling's solution, but 

 it did so after it had been acidulated with weak sulphuric acid. 



The production of this decomposition in the cold by the action of dilute acids was 

 further examined. 



It was found that when a 3 or 4 per cent, solution of alcoholic extract in water is 

 acidified with sulphuric acid, so that the acid is present as a 0'3 to 2 per cent, solution, 

 the mixture in a short time becomes turbid, an apparently amorphous deposit forms 

 in it, and in from two to four days the solution becomes clear and less coloured, and 

 small crystalline tufts appear at the bottom and sides of the vessel, which increase in 

 size until a considerable crystallisation has been produced. To this crystalline substance 

 I have given the name Strophanthidin. On examining the solution in which the crystals 

 have appeared, it is now found to contain much glucose. 



When a minute quantity of the extract dissolved in a drop of water is placed on a 

 microscope slide provided with a shallow cup, and a drop of 2 per cent, sulphuric acid is 

 added to it before the cover-glass has been applied, in one or two days a large number of 

 small and translucent globular bodies make their appearance, and in three or four days a 



