162 VENOMS 



on the contrary, it diminishes that of the venom of ViPERiDiE by 

 nearly one-half. 



By using a special filter at a pressure of 50 atmospheres, C. J. 

 Martin has succeeded in separating from the venom of an Australian 

 Pseudechis two substances : a non-diffasible albuminoid, coagulable 

 at 82° C, and a diffusible, non-coagulable albumose. The former 

 produces hssmorrhages ; the second attacks the nerve-cell of the 

 respiratory centres. 



All venoms exhibit most of the chemical reactions characteristic 

 of the proteids : — 



Millon's reaction. 



Xantho-proteic reaction (heating with nitric acid and subsequent 

 addition of ammonia = orange coloration). 



Biuret reaction (caustic potash and traces of sulphate of copper). 



Precipitation by picric acid, disappearing on being heated, re- 

 appearing when cooled. 



Precipitation by saturation wibh chloride of sodium. 



Precipitation by saturation with sulphate of magnesium. 



Precipitation by saturation with amtnonium sulphate. 



Precipitation by a 5 per cent, solution of sulphate of copper. 



Precipitation by alcohol. 



According to C. J. Martin and MacGarvie Smith, the albumoses 

 of the venoms of CoLUBBiDiE are hetero-albumoses, proto-albumoses, 

 and perhaps deutero-albumoses in small quantities. They can be 

 separated in the following manner: — 



The solution of venom is heated to 90° C, and filtered in order 

 to separate the albumins coagulable by heat. The filtrate, saturated 

 with sulphate of magnesium, is shaken for twelve hours. By this 

 means there is obtained a flocculent precipitate, which is placed 

 upon a filter and washed with a saturated solution of sulphate of 

 magnesium. The filtrate is dialysed for twenty- four hours in a 

 stream of distilled water, and then concentrated, likewise by dia- 

 lysis, in absolute alcohol. Thus we obtain a few cubic centimetres 



