212 TOXINES AND ANTITOXINES. 



In this way he obtained 42 mgrms. of a dry residue, which 

 still showed the biuret and Millon's reaction, but no other 

 proteid reactions. The poison will pass readily through a 

 Chamberland filter. 



Chemical Nature of the Toxine. After it had been found that 

 the active agent was not an alkaloid there followed the usual 

 period of toxalbumins, which to-day are practically discarded in 

 the case of bacterial poisons. It is probable that snake poisons 

 also are not proteids in the stricter sense of the word, and if 

 that is so the attempts that have been made to investigate the 

 proteids combined with them are, in the main, only interesting 

 from the historical point of view. 



WEIR MITCHELL found albumins in the poison of Crotalus durissus 

 (rattlesnake), while WOLFENDEN l isolated various proteids (globulins, 

 albumin, and albumoses), but no peptone from the venoms of the cobra and 

 Daboia. KANTHACK 2 regarded the poison as a proto-albumose. MARTIN 

 and SMITH 3 found a non-poisonous albumin, and two poisonous albumoses, 

 a hetero- and protalbumose, but no peptone in the poison of Pseudechis 

 porphyriacus and Hoplocephalus curtus. 



As regards the constitution of the toxines themselves nothing 

 is known. 



Properties of the Toxine. Snake poison shows all the proper- 

 ties characteristic of impure toxines as regards precipitability, 

 &c. Cobra poison, however, according to CALMETTE, forms an 

 exception in not being carried down by freshly precipitated cal- 

 cium phosphate, which is otherwise a general characteristic of all 

 these colloids. It is also not precipitated by magnesium sul- 

 phate, and thus contains no globulin. 



It dialyses slowly, but appreciably. Viper venom is weakened 

 by passage through a porcelain filter (PmsALix 4 ). It is much 

 less affected by heat than other haptines. Cobra poison can 

 resist a temperature of 90 C. for an hour, and of 38 C. for a 

 day ; it is only slightly injured by being kept at 97 C. for half 

 an hour, but its activity is completely destroyed after exposure 

 for the same length of time at 98 C. On the other hand, the 

 purified poison (CALMETTE, 1890) is very susceptible to a tem- 

 perature of 80 C., a solution in distilled water being more 

 affected than in that containing salt or glycerin. This is also 



1 Wolfenden, "The Venom of the Indian Cobra," Journ. of PhysioL, 

 vii., 327, 1886 ; id., "The Venom of the Indian Viper (Daboia)," ibid. 



2 Kanthack, " The Nature of Cobra Poison," Journ. of PhysioL, xiii., 272, 

 1893. 



3 Martin and Smith, " The Venom of the Australian Black Snake," Proc. 

 Roy. Soc. New South Wales, 1892, 240; Malys Jb., 1894, 404. 



4 Phisalix, Soc. BioL, xlviii., 233, 656, 1896. 



