48 Society for Experimental Biology and Medicine. 



Like the soap fraction of blood or organs, all these soaps be- 

 come inactive when mixed with a certain amount of serum. This 

 inactivation is again an apparent one, because the presence of suit- 

 able immune bodies hinders the paralyzing action of the serum to 

 a great extent, or such mixture may be inactive upon normal cor- 

 puscles, but active upon those which have been sensitized properly. 

 This complementary action of the mixture of soap and serum is 

 absent at 0° C. and disappears at 56 0 C, or with age. Chlorides, 

 sulphates or acetates of calcium or barium inactivate the mixture, 

 just as in the case of serum complement or " extract complements." 

 This inactivation cannot be anything more than the formation of the 

 insoluble, inactive soaps. The action of various acids and alkalies 

 is exactly the same as in the cases of complement and " ex- 

 tract complements." 



In this place I must not omit reference to certain interesting 

 phenomena which I met with during the experiments on soaps as 

 venom activators. As we have shown elsewhere, venom is inac- 

 tive without the aid of a second substance. We found that this sec- 

 ond substance can be the complement of serum. Kyes discovered 

 later that lecithin is activating for venom, and thinks this is the 

 only class of bodies which is responsible for venom hemolysis. 

 Complement has been placed in a doubtful position as a venom 

 activator. My present work, however, again upholds our previous 

 view that complement is a very important venom activator of serum. 

 Certain fresh serums contain venom activator. If we add to such 

 serums certain amounts of calcium chloride, their activating property 

 is easily destroyed. Complement also disappears in these instances. 

 But if we heat the inactivated serums to 75 0 C. or higher, then they 

 acquire a new, powerful, venom activating property, which cannot 

 be removed by calcium chloride. On the other hand, ox serum 

 contains almost no venom activator in the fresh state, but acquires 

 one when heated to 75 0 C. or higher, and this acquired activator 

 cannot be inactivated by calcium chloride. If we take two tubes 

 of fresh ox serum and add soap to one and lecithin to the other, 

 we get venom hemolysis in both tubes. But if, before we add 

 venom, we introduce a certain amount of calcium chloride into 

 each tube, and then venom, venom hemolysis will occur in the 

 tube with lecithin, but not in the tube with soap. It would be 



