DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 1003 



7. Platinic chloride failed to produce any change within several hours, but on the 

 following day a slight brownish opalescence had occurred. 



8. Phospho-molybdic acid produced a very pale greenish-yellow precipitate, permanent 

 only with a considerable quantity of reagent. When the precipitate had subsided, the 

 supernatant fluid was seen to be emerald-green ; and the precipitate dissolved on boiling, 

 and reappeared on cooling. 



9. Molybdate of ammonium produced a faint yellow tint, and, after several hours, a 

 considerable yellowish-white precipitate, the supernatant fluid continuing to be yellow. 

 The precipitate dissolved on boiling, and appeared again on cooling. 



10. Tannic acid produced a copious white precipitate. 



11. Solution of potash, soda, ammonia, lime, and baryta, and of carbonate of potash and 

 carbonate of soda, each produced a bright orange-yellow colour. Carbonate of ammonium, 

 carbonate of baryta, and bicarbonate of potash produced a less marked yellow. In each case, 

 the yellow colour was immediately discharged by dilute acetic acid. The alkaline yellow 

 fluids did not reduce Fehling's solution when boiled with it. 



12. Sulphuric acid (10 per cent.), dilute hydrochloric acid (Ph. Br.), dilute nitric acid 

 (Ph. Br.), and dilute phosphoric acid (Ph. Br.) each rendered the solution paler, and slowly 

 produced a slight flocculence, which disappeared in great part on boiling. When 

 afterwards neutralised and tested with Fehling's solution, a well-marked reduction 

 occurred. 



13. Dilute acetic acid (Ph. Br.) produced no obvious change; and after boiling for a 

 few seconds, and neutralising with sodium carbonate, only a slight reduction of Fehling's 

 solution was obtained. 



No obvious change was produced by picric acid, carbonateof b aryta, phosphate of sodium, 

 chloride of gold, mercuric chloride, potassio-mercuric iodide, metatungstate of sodium, tri-iodide of 

 potassium, potassio-bismuthic iodide, nor potassio-cadmic iodide. 



Absence of any Alkaloid from the Extract. 



The failure, already described, of many reagents for alkaloids to produce change in the 

 watery solution of the extract, although it is naturally acid in reaction, affords sufficient 

 evidence of the absence from the seeds of any alkaloidal principle. 



In addition to this negative evidence, ten grains of the extract were treated according to 

 Stas' method for separating alkaloids, ether and chloroform being used as the separating 

 solvents; but the result was also entirely negative, only 0'035 grain of total product 

 ( = 0"35 per cent.) having been obtained, which with sulphuric acid and heat gave 

 merely colour changes characteristic of strophanthin. 



At the same time, the extract contains nitrogen in small quantity, but this is by no 

 means remarkable when its composition is borne in recollection. 



Further, when the extract is made alkaline by solution of potash and then heated, 

 alkaline vapours, having a distinctly ammoniacal or, rather, methylamine odour, are 

 evolved. 



VOL. XXXV. PART IV. (NO. 21). 7 N 



