~>0 Agglutimns find Precipitins 



anti-tetanus serum agglutinates B. tetani, but does not produce a pre- 

 cipitum in culture fluids of this micro-organism. Nolf (v. 1900) found 

 that a serum may contain a precipitin but no agglutinin, and concluded 

 therefrom that they are distinct. Radziewsky (1900, p. 434) also considers 

 the antibodies distinct. Bail (1901) found that after all the precipit- 

 able substance had been removed, by adding antiserum to a diluted 

 agglutinating serum, the latter retained its power to agglutinate 

 unimpaired, as tested on B. typltosus. Both Eisenberg (5, v. 1902) and 

 Beljajew (1902) note the parallelism between the power of agglutination 

 and precipitation possessed by antisera. The latter observed that 

 precipitins appear much more slowly during immunization than agglu- 

 tinins, and consequently they must be distinct. In both cases we 

 have to deal with substances which appear to enter into chemical 

 combination in definite proportions; both are stable bodies, and resist heat 

 more than do others. There appears to be a difference though, in this 

 resistance to heat: thus Pick (1902, in. p. 81). working with antityphoid 

 serum, which he heated to 58 60" C., found that the bacterio-precipitins 

 were inactivated ; not so the agglutinins, for which reason he considers 

 them distinct antibodies. Kraus and Eisenberg (27, n. 1902) found that 

 the precipitins acting upon their homologous blood did not carry down 

 diphtheria antitoxin, or the typhoid agglutinin they contained. They 

 were unable to obtain diphtheria anti-antitoxin, or typhoid anti- 

 agglutinin, by treating rabbits with the respective antitoxic and 

 agglutinative sera, whereas they obtained anti-lactosemm (see under 

 Lactosera), viz. antiprecipitins. The resistance of precipitins to heat, 

 as proved by a number of observers, will be referred to presently. 

 Ford (3, vil. 1902, p. 371) does not consider that the non-identity of these 

 antibodies is proved. See also Wassermann (1903). 



