Serum Conij^lemeiif 29 



like body, or complement, is not specific, for the reason that complement can be 

 supplied from another animal which has not been treated. (The toxophorous group 

 of the toxin molecule is also regarded as non-specific by Ehrlich.) Some authors 

 consider that there is but one complement in cytolytic sera, this being the alexin 

 of some writers, whereas Ehrlich and his school claim that any serum contains a 

 multiplicity of complements. A number of points in connection with complements 

 have been considered in the preceding pages, and it is not my object to enter 

 at all fully into a consideration of them here. It will suffice to mention a few facts 

 indicative of their importance. 



The amount of complement in serum appears to vary considerably. Thus 

 Weichardt (25, xi. 1901, p. 834), using normal rabbit sera to reactivate spermotoxic 

 guinea-pig serum, found that only 5 out of 11 rabbits' sera contained complement 

 suitable for reactivation. Serum obtained from a man contained complement at 

 one time, none when tested after a period of 8 weeks. Sweet (xii. 1902) has 

 collected the data contained in the literature relating to the variation in the 

 complement-content of cytolytic sera. A decrease in complement was observed by 

 Abbott and Bergey (1902) in the serum of rabbits treated with ox corpuscles, the 

 animals also receiving alcohol. Ehrlich and Morgenroth (1900) found a decrease 

 in complement in rabbits which had received a dose of phosphorus sufficient to 

 kill them after the lapse of 3 days ; the haemolytic power of their serum had 

 disappeared on the second day in a manner corresponding to what is seen in sera 

 inactivated by heat. Metalnikoff (1900) observed a decrease of complement in a 

 rabbit treated with guinea-pig spermatozoa, an enormous abscess having formed, 

 which subsequently burst and healed. When fresh guinea-pig serum was added to 

 this rabbit's serum it was spermotoxic, not otherwise. On the other hand, Nolf 

 (1900) claimed to observe an increase in complement in animals treated with fowl 

 serum ; Miiller (1901) made observations which show that the complement-content 

 may be increased by injecting peptone solution, bouillon, aleuronat solution, in 

 other words indifferent fluids. Sweet, from whom I have made these citations, 

 studied the question in rabbits immunified with ox corpuscles. He found that he 

 could increase the complement-content by the injection of substances having a 

 positive chemotactic action on leucocytes, using Staphylococcus pyogenes aureus, 

 sterile oil of turpentiiie, sterile aleuronat suspension. He found the haemolytic 

 complement in a free state in the blood plasma, and in the serous part of an 

 exudate, not being contained in leucocytes, nor being set free by the process of 

 coagulation. 



The relation of complement in a serum containing blood corpuscles subject 

 to the action of snake venom has been very clearly brought out by Flexner and 

 Noguchi (1902). These authors experimented with the haemolysins contained in 

 the venoms of Crotalus adamanteus (rattlesnake), Ancistrodon piscivorus (water- 

 moccasin), Naja tripudians (cobra), and Ancistrodon contortrix (copperhead). They 

 found that when they had thoroughly washed the blood corpuscles of the dog, 

 sheep, ox, pig, rabbit, and guinea-pig, that the corpuscles were unaffected by 

 contact with these venoms. On the other hand if the corpuscles were bathed 

 in their respective complement-containing sera, haemolysis took place promptly 

 upon the addition of the venoms. An excess of serum increased the haemolytic 

 power. They found : 



