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INFECTION AND RESISTANCE 



tered bacteria, and, on the other, to bacteria which had absorbed 

 agglutinin. It is seen that, with some salts, agglutination of the 

 unaltered bacteria did not occur at all, whereas agglutination was 

 brought about in the treated bacteria with comparatively small 

 amounts ; in other cases the difference is a quantitative one only : 



Protocol constructed from the tables of Neisser and Friedemann, loc. cit. 



The analogy between the experiment tabulated in the preceding 

 protocol and the following from the work of the same writers is self- 

 evident. Just as the absorption of agglutinin by bacteria rendered 

 these more amenable to precipitation by salts, so the addition of 

 minute quantities of gelatin to mastic emulsions had a similar sensi- 

 tizing effect upon these. 



Finally, one of the most important analogies yielded by the work 

 of the above investigators is illustrated in the following protocol : 



