POISONOUS SNAKES OF NORTH AMERICA. 46 i 



other peculiarities, possessed tbe property of immediately precipitating 

 Prussian blue wlien treated successively with ferrocyauide of potassium 

 and the ferric salts. He expressly remarks, however, that these alka- 

 loids do not constitute the most dangerous part of the venom, which 

 he asserts is of a nitrogenous nature. They seem chiefly to stupify, 

 but are not necessarily fiital. In the course of the discussion he fur- 

 ther emi)hasized the fact that these leucomames in the normal state of 

 the tissues only occur in minimal proportions {toni. cif. p. 431), 



Other careful investigations simultaneous with and later than tliose 

 of Prof. Gibbs have fully substantiated the claim that theleucomaiues 

 play no role in the poisoning, and that, if present, they form no essen- 

 tial part of the venom. Dr. Wolfenden {loc. cit. p. 335) made examina- 

 tions of cobra venom by the Stas-Otto method for ptomaine, or alkaloid, 

 in three different instances, but did not succeed in linding the slightest 

 trace of any such body. There was neither trace of fixed nor volatile 

 alkaloid, the residues were noncrystalline and, moreover, nontoxic, and 

 gave none of the alkaloidal test reactions. 



Prof. Gautier, as I have already intimated, insisted that the toxic 

 constituent of the venom is of a different nature. The researches of 

 the last ten years have proved beyond a shadow of doubt their proteid 

 nature, and that Bonaparte was correct when, in 1843, he referred to it 

 as an albuminoid. 



The achievements during the last decade in the study of the chem- 

 istry of snake venoms have been of such a nature, are so recent, and 

 even now progressing, that the best way to record them is to treat them 

 historically and chronologically. 



The tirst progressive step was taken when, in 1883, Dr. S. Weir 

 Mitchell and E. T. Reichert, of Philadelphia, laid before the National 

 Academy a preliminary report on the results of studies, which, after a 

 lapse of twenty years, Dr. Mitchell had resumed. He had in some way 

 become convinced that the complexity of the symptoms in snake 

 poisoning could not be the result of a single simple constituent, but 

 that they might be explained by the assumption of a similarly complex 

 nature of the albuminoid body, the crotaline, previously thought to be 

 simple. Dr. Mitchell, in a later popular article,* has given a clear and 

 interesting insight in the mental process Avhich led to the important 

 discovery and the laboratory processes by which it was demonstrated, 

 from which vvc make the following abstracts: 



When I first studied tliis strange poison I thought of it as a single albuminous 

 body. As such it had always been regarded since it had been proved by Priuco 

 Bonaparte to belong to the albuiuens. When once I chanced to think that venom 

 might be a complex lluid, holding in solution more than one poison, reasons for such 

 a belief multiplied^ and so excited my interest that, in 1882, Avith Prof. Eeichert's 

 aid, I began to put my theory to the sharp test of experiment. To prove in the 

 outside laboratory what the inside mental laboratory has comfortably settled is not 

 always easy, and many months of careful research were reijuired before the answer 



* Century Magazine, N. York, xxxviii, Aug. 1889, pp. 503-514. 



