SUBSTANCES WHICH ACTIVATE COBRA VENOM 



457 



tween amboceptor and complement would be very similar in this 

 case. In our studies in haemolysis due to cobra- venom-lecithin we 

 have therefore been able to observe the same mutual dependence 

 between amount of amboceptor present and the complement re- 

 quired which the researches of von Dungern, 1 Gruber 2 and Morgen- 

 roth and Sachs 3 showed to exist in their experiments. The rela- 

 tion between these amounts is such that when large amounts of 

 amboceptor are present, smaller doses of complement suffice for 

 haemolysis. 



To be sure, when an inordinately large amount ot cobra venom 

 is added the amount of lecithin required for complete solution is 

 also larger, as has already been mentioned by Kyes. This is evi- 

 dently explained by assuming that when the amount of amboceptor 

 is excessive the distribution of the lecithin is such that part of the 

 amboceptor loaded with lecithin is deflected and does not come 

 into action. If, however, the amount of cobra venom is decreased^ 

 results will be obtained which, within wide limits, agree with those 

 observed by Morgenroth and Sachs (1. c.) with serum haemolysins- 

 The more cobra venom one adds the less lecithin will be needed to effect 

 complete haemolysis, and, conversely, in adding larger amounts of 

 lecithin the minimal complete solvent dose of the cobra venom is 

 constantly decreased. This is well shown by Table XII. 



TABLE XII. 



1 cc. 5% Ox Blood. 



B. 



1 cc 5% Ox Blood. 



From these experiments we see that the quantitative relations 

 which exist between cobra venom and lecithin furnish an additional 



1 von Dungern, page 36. 



2 Gruber, Wiener klin. Wochensch. 1902, No. 15. 



3 Morgenroth and Sachs, pages 233 and 250. 



