807 



able portion remained undissolved even when the extraction was 

 performed with a large amount of ether. In a small amount hardly 

 anything was dissolved. 



[t stands to reason that in our fuither experimentation we did 

 not attempt to prepare an ether-extract, but that the residue of the 

 alcoholic solution was only washed with a little ether. Wliat was 

 then left, was taken up in water and treated as follows: 



Sulphuric acid was added to the solution to 5 per cent, and a 

 concentrated solution of phosphotungstic acid was added, which 

 produced a large, white precipitate. This was filtered by suction, 

 washed and decomposed in the usual way with baryta water. The 

 filtrate was freed from phosphotungstic acid by baryta and the 

 solutions ihus formed, were examined for their effect upon the 

 surviving small intestine of a rabbit.') It appeared from this that, 

 when we work with concentrated solutions, about S0\/„ — 907o of 

 the active constituent had been precipitated with phosphotungstic 

 acid. Admixture of silvernitrate and silvernitrate with baryta yielded 

 in the solution, through decomposition of the phosphotungstic 

 precipitate, only inconsiderable residues, which generally contained 

 no active substance. But in the filtrate of these precipitates we have 

 not been able to find an undiminished quantity of the active sub- 

 stance. If this filtrate was evaporated down, after removal of traces 

 of silver-salt and baryta, and subsequently extracted repeatedly with 

 slight quantities of absolute alcohol, an addition of alcoholic subli- 

 mate solution gave a white precipitate, which contained the active 

 substance, though not in toto. By extracting this precipitate with 

 boiling water and concentrating this solution, we could not manage 

 to abstract a pure mercuric chloride. Just as with sublimate we also 

 obtained with platinic-chloride in alcoholic solution a precipitate that 

 principally contained the active substance. This precipitate with 

 platinic-chloride was soluble in a very small quantity of water. 

 By concenti-ating the solution or by addition of alcohol no pure 

 compound was set free. After decomposing the platinum-compound 

 with hydrogen sulphide and addition of gold-chloride solution only a 

 few crystals segregated, which melted at 215° — 222°. A repetition of 

 this experiment with a large amount of material did not enable us to 

 isolate the active substance or a compound of it in a pure condition. 

 The quantity of the gold-salt was very small and contained only a 

 portion of the active constituent of the primary intestine extract. 



1) The extracts were always examined for their effect after Magnus' method 

 with the excised small intestine of the rabbit in 50 cc. of Tyrode-fluid at 38°. 



