THE COMPOUND H.EMOLYSINS 239 



consumed to a sensible degree in the formation of the 

 haemolysin. Therefore in the formulae x is always sub- 

 tracted from the equivalent quantity of immune-body and 

 alexin. In another simikr case, namely, the formation of 

 the haemolytic substance cobra-lecithid from cobra-poison 

 and lecithin, the quantity of haemolysin seems always to 

 be so small that it makes no difference if it be subtracted 

 from the quantities of cobra-poison and lecithin or not. 

 The experiments were carried out with a o. i per cent solu- 

 tion of cobra-poison (i c.c. = 10,000 units) and a i per cent 

 solution of lecithin (i c.c. = 1000 units). The arrange- 

 ment of the table is the same as in the foregoing. 



The calculated values were obtained with the aid of the 

 formula : 



C (L- i. 5)1 = 6.67*2 = 6.67/2, 



where C represents the quantity of cobra-poison added, L 

 the corresponding quantity of lecithin, x the quantity of 

 haemolysin formed, and h the observed quantity of haemo- 

 lysis tabulated above. As will be seen from the equation, 

 no haemolysis occurs until 1.5 units of lecithin have been 

 added. This quantity was determined by special experi- 

 ments. The experiments with cobra-lecithid indicate that 

 this poison behaves a little differently than the other 

 haemolysins. With these a limit of the reaction was prac- 

 tically reached on standing for two hours in an incubator 

 at 37 C., and afterwards for seventeen hours in a refrig- 

 erator. But in the case of cobralysin, haemolysis continued 

 in the sedimented blood-corpuscles after the observations 

 cited above were ended, so that the result was wholly dif- 

 ferent after an additional twenty-four hours, during the 



