BACTERIOLYSIS AND ALLIED PHENOMENA 171 



complement, is injected into a rabbit. This is supposed to develop 

 an anticomplement in virtue of the complementoids it contains ; 

 we know that it also develops a precipitin which combines 

 with the proteids of goat serum, and in doing so entangles any 

 complement which may be present. Now the complement of 

 goat serum can dissolve ox corpuscles when sensitized by a 

 suitable amboceptor (e.g., serum of a rabbit which has been 

 injected with ox corpuscles). When, however, the serum of the 

 normal goat is mixed with that of the rabbit which has been 

 injected with rabbit serum and used in this way, no haemolysis 

 occurs. This Ehrlich explains on the supposition that the rabbit 

 serum contains anticomplement, but it is also explicable, as 

 Moreschi and Gay have shown, on the supposition that the com- 

 plements are all absorbed in the precipitate (perhaps an invisible 

 one) formed in the mixture. 



It is obvious that either interpretation may be the correct one, 

 or that both processes may come into play. Moreschi has 

 investigated the process further, and his results tend to show that 

 the experiment is best explained on the absorption of complement 

 theory, and not by the presence of anticomplement. One of his 

 experiments, and that very ingenious, will be described. He 

 injected a rabbit with hen's egg albumin, and obtained a precipitin 

 to that substance ; this he found to act as an anticomplement 

 to fowl serum, but not to that of the rabbit, guinea-pig, or goat, 

 to which, of course, it was not a precipitin. He found, however, 

 that if he added to any of these latter sera a minute trace (^^^ 

 of its volume) of egg-albumin, it appeared to become so, the 

 explanation being that a precipitate was formed, and that the 

 complements were entangled in it. 



The phenomenon has also been invoked to explain some extremely 

 interesting researches of Pfeiffer and Friedberger, who thought 

 they had demonstrated the presence of antibacteriolytic substances 

 in normal serum. They prepared a mixture of cholera vibrios 

 and normal serum, which they allowed to stand for some time, and 

 then removed the bacteria by centrifugalization. This would 

 remove any amboceptor which the serum might contain, and they 

 thought that they could demonstrate that an anti-amboceptor 

 still remained. They added to the serum thus prepared some 

 anticholera serum in suitable amount and a lethal dose of cholera 

 vibrios, and injected the whole into an animal, which invariably 

 died ; the amount of antiserum was sufficient to protect it if no 



