SUBSTANCES WHICH ACTIVATE COBRA VENOM. 463 



in this the ratio was still 1 : 200. A lecithin obtained from E. 

 Merck behaved similarly. Nevertheless all of these preparations 

 were exactly equal in their activating power. It is hard to say whether 

 possibly the cholin radical or the fatty-acid radical represents the 

 active toxophore group of the combination formed by the union of 

 the lecithin with the cobra venom. It may be mentioned, however, 

 that neutralized cholin exerts no haemolytic effect, and that sinapin l 

 (the sinapic acid ether of cholin), despite the cholin radical which it 

 contains, possesses no activating power. We are therefore inclined 

 to believe that the toxic action is caused by the fatty-acid radical 

 in the lecithin molecule. This also agrees with the hsemolytic action 

 observed by us in neutralized stearylglycerophosphoric acid and in 

 the above-mentioned fats and fatty acids. We shall report on further 

 researches in this direction at a subsequent period. 



In conclusion we may be permitted to discuss briefly a few inci- 

 dental observations. Among these is the fact that hydrochloric acid 

 not only causes no destruction or weakening of the cobra venom, 

 but even exerts a marked protective action on the same. A venom, 

 solution which completely loses its activity by heating to 100 C. 

 for twenty minutes can be heated for half an hour to 100 C. without 

 losing its hsemolytic property if it contains l /\&n HC1. Not until 

 the poison containing the acid is heated for two hours to 100 C. 

 is destruction complete. Possibly the protection exerted by the acid 

 may indicate the basic character of those binding groups of the 

 cobra-venom molecule which are here concerned. So far as the 

 influence of other agents on the cobra venom is concerned we shall 

 only mention that all procedures which prevent the action of the 

 cobra venom in the animal body - (an action due mainly to the 

 neurotoxic components of the poison 3 ) also destroy the hsemolytic 

 action of the venom. Examples of this are powerful oxidizing sub- 

 stances (potassium permanganate, chloride of lime, chloride of gold, 

 soda lye, etc.). 



1 For this we are indebted to Geheimrath Schmidt in Marburg. 



2 See especially the detailed and excellent investigations of Calmette, Annalea 

 de 1'Inst. Pasteur, T. VIII, 1894. 



3 See Flexner and Noguchi, 1. c. 



