140 PROPERTIES OF ANTI-SERUM TO SERUM 



With 0-001 c.c. of serum six haemolytic doses of complement 

 produce only a trace of lysis. It is also to be noted that if 

 we take the first tube in the series where any lysis is present, 

 much more than a dose of complement must be added before 

 lysis is complete : for example, with 0-000,1 c.c. of serum two 

 doses must be added in order that lysis may be complete. 

 If we suppose that a new body is formed by the union of a 

 molecule in the serum with one in the anti-serum, then the 

 combination of this new body with complement presents 

 phenomena well recognized to obtain in the case of the 

 union of toxin and anti- toxin the so-called ' Ehrlich's 

 phenomenon ', and also described above (p. 32) in connexion 

 with the absorption of complement by sensitized red cor- 

 puscles. 



The table also shows that increasing amounts of serum 

 lead to the taking up of more complement, though this does 

 not occur in arithmetical proportion. This point will, 

 however, be referred to below. 



The following table shows the result of a similar experi- 

 ment with anti-human serum. 



Anti-serum rabbit v. man, 0-05 c.c. to each tube. 



Test for complement = 0-5 c.c. suspension of ox's corpuscles treated with 

 immune-body. 



TABLE 2 



From the above it will be seen that 0-000,01 c.c. human 

 serum produces distinct deviation. Precipitin tests were 

 carried out at the same time with the result that 0-000,1 c.c. 



