106 



Dr. S. Martin. The Toxic Action of the [May 16, 



and the toxic principle of snake- venom. Weir Mitchell and Reicherfc* 

 have shown that in the American rattlesnakes, the venom contains two 

 poisonous proteids, globulin and a "peptone." The coagulation tem- 

 perature of the globulin described by them is between 60° and 70° C. 

 The peptone is not a true peptone, as physiological chemists now 

 understand the term ; since it is, according to Mitchell and Reichert, 

 precipitated by acetic acid and potassium ferrocyanide. Their 

 peptone, indeed, seems more allied to the albumoses. In the venom 

 of the mocassin, e.g., the "peptone" is precipitated by adding an 

 excess of NaCI to the solution, besides being thrown down by dilute 

 acetic acid. The peptone found by these observers in cobra- venom is 

 precipitated by acetic acid and potassium ferrocyanide, as well as by 

 j^TaCl added to saturation. A true peptone is not precipitated in this 

 manner, and I cannot but conclude that the body found by Mitchell 

 and Reichert is closely allied to the albumose class of proteids. 



The globulin of abrus-seed coagulates between 75° and 80° C. in 

 10 per cent, magnesium sulphate solution and between 66° and 73° C. 

 in 10 per cent. I^aCl solution.f The coagulation temperature in the 

 last solution therefore nearly corresponds to the coagulation tempera- 

 ture of the venom globulin of the rattlesnakes. Mitchell and Reichert 

 do not mention in the presence of which salt the globulin was coagu- 

 lated. Sodium chloride distinctly lowers the temperature of coagula- 

 tion. 



Abrus-albumose, moreover, closely resembles the " peptones " and 

 " peptone-like " bodies found by the observers in snake-venom. 

 Like them it is uncoagulated by heat,! it is precipitated by acetic 

 acid, and by acetic acid and potassium ferrocyanide, and also by 

 saturation with sodium chloride in an acid solution. 



Other observers have described in cobra- venom a poisonous albumin 

 and acid albumin (Wolfenden). 



Nature of Poison. — I do not propose here to discuss fully the nature 

 of snake-venom. The results of Mitchell and Reichert's researches 

 I would wish to refer to are : — (1) That both the globulin and peptone- 

 like body present in the venom of the rattlesnake are poisonous ; (2) 

 that the severe local ecchymosis produced by viperine venom is due to 

 the globulin present in it, since such local effect does not occur after 

 inoculation if the globulin be removed from venom. The third point 

 I would wish to refer to is the effect of heat on the activity of rattle- 

 snake venom. If the venom of the Diamond head (Crotalus adaman- 

 teus) be heated up to 74° C. the venom is still active ; if up to 



* 'Researches upon the Yenom of Poisonous Serpents.' Philadelphia 1885. 

 f 1 Roy. Soc. Proc.,' vol. 42, p. 333. 



X Mitchell and Reichert state that cobra-venom may be boiled and filtered ; and 

 the filtrate will after a time give a further precipitate on boiling. They explain 

 this by saying a coagulable body is formed from a non-coagulable. 



