BACTERIOPHAGOUS ANTISERUM 135 



of Bordet and Gengou, can not be made. In effect, the culture 

 of the anti-dysentery bacteriophage is only a suspension of ul- 

 tramicrobes in a liquid containing the dissolved substance of the 

 dysentery bacilli, so that the antibacteriophage-Shiga serum con- 

 tains two amboceptors, one specific for the dissolved substance, 

 the other for the ultramicrobe, and it is impossible to separate 

 the two actions. A fixation of complement would always be 

 obtained without the possibility of knowing with which of the 

 two antigens it had been effected. However, the question can 

 be solved in another manner; a manner which is very conclusive. 



We have considered in the preceding chapters the experiments 

 which demonstrate the unicity of the bacteriophage. If the 

 hypothesis based on these experiments is true the amboceptor 

 present in the antibacteriophage-Shiga serum ought to fix comple- 

 ment with all ultramicrobes and the detection of an amboceptor 

 ought to be possible, for working with a culture of bacteriophage 

 other than the antidysenteric there would be nothing to inter- 

 fere with the reaction. A culture of antiplague bacteriophage, 

 for example, is a suspension of ultramicrobes in a fluid containing 

 the substance of B. pestis. The only possible common element 

 in a culture of antidysentery bacteriophage and in a culture 

 of antiplague bacteriophage is the bacteriophagous ultramicrobe. 

 And the single "anti" element contained in an antibacterio- 

 phage-Shiga serum capable of exercising an action toward such a 

 plague culture can only be an amboceptor for the single element 

 common to all cultures of the bacteriophage; the bacteriophagous 

 ultramicrobes themselves. 



The complement fixation reaction has been conducted utiliz- 

 ing as antibody the antibacteriophagous-Shiga serum; as anti- 

 gens, cultures of bacteriophage for dysentery, plague of human 

 origin, an anti-plague strain from rats, and an anti-barbone 

 strain from the buffalo. 



Experiment XLVI. Fixation of complement. 



Antigen: culture of anti-Shiga bacteriophage containing 2,000,000,000 

 ultramicrobes per cubic centimeter. 



Antibody: antibacteriophage-Shiga serum. 



With the antigen in an amount of 1 cc. and antibody in quantities of 0.2 

 and 0.1 cc. fixation is positive. 



