THE CHEMISTRY OF VENOMS. IT 



The following are some of the reactions given by this substance (the water-venom- 

 cjlobulin suspended in distilled water): — 



Boiling — coagulates. 



Sodic chloride (0.75 per cent.)— insoluble. 



(10 " ) — soluble; boiling gives slight turbidity. 



— sodic chloride solution apparently unaffected by carbonic acid. 

 Carbonic acid — insoluble. 



Sodic carbonate — soluble, slightly turbid solution; boiling makes perfectly clear. 

 Hydrochloric acid (0.4 per cent.) — soluble. 

 Melaphosphoric acid — insoluble; boiling no appreciable effect. 

 Orthophosphoric acid — very soluble; boiling makes solution absolutely clear. 

 Sodic metaphosphate — insoluble; boiling no appreciable effect. 

 Sodic orthophosphale — somewhat soluble ; boiling renders perfectly clear. 

 Potassic sulphate — somewhat soluble. 



Calcic chloride — soluble ; opalescence of solution increased by boiling. 

 Acetic acid (5 per cent.) — soluble. 

 Acetic acid (glacial) — soluble. 



Cobra-venom-peptone. — The venom-peptone from Cobra may be prepared by 

 boiling, thus coagulating the globulin, or by dialysis. Great difficulty is expe- 

 rienced in the former process, since the coagula are so fine that it is impossible, 

 save in rare instances, to obtain a clear nitrate, and as to these we have no explana- 

 tion to offer for the exception. The peptone prepared by boiling or by dialysis 

 gives identical reactions. 



Before detailing the reactions of this body it may be well to notice a peculiar 

 property exhibited by all venom-peptones which gives them a very distinguishing 

 feature. After boiling the venom for a few minutes and then filtering, the filtrate 

 will again give further coagula by continued boiling, and so the process of boiling 

 and filtering, and reboiling the filtrate may go on repeatedly, yet the clear filtrate 

 will in every instance give fresh coagula. Indeed the boiling process may be con- 

 tinued for an hour or more, and yet at the end of that time the filtrate will still 

 yield coagula. However, after the venom solution has once been boiled, coagula- 

 tion does not recommence in the filtrate until it has been boiled for a few moments. 

 These most interesting facts suggest that the coagula formed after the first boiling 

 are due to a gradual decomposition of what is in some sense a non-coagulable pro- 

 teid, since coagulable proteids all coagulate at once and completely when a definite 

 temperature is reached ; the coagula which follow repeated or prolonged boiling 

 appear to be due to such a decomposition of proteids as violent chemical or physi- 

 cal action could alone account for. 



It seems to us perfectly clear that the body which is thus gradually broken up 

 by prolonged boiling is a peptone. Our principal reasons for this belief are that 

 the body so coagulated is very readily dialysable, is not precipitated by ferric 

 chloride, or cupric sulphate, and in the case of the Cobra is not precipitated by abso- 

 lute alcohol, or mercuric cliloride, is not coagulated below the boiling point, and in 

 fact not until boiling has gone on for a few moments. The following reactions 

 seem to be sufficiently characteristic. 



These results we obtained from a solution of the Cobra-venom-peptone obtained 



3 April, 1886. 



