1909.] 



Hcem-agglutinim, etc., in the Blood. 



69 



unwashed red cells were poundcHl in a mortar with fine glass and then 

 allowed to stand all night. The red fluid ohtained after eentrif'ugalisation 

 was completed was then tested on samples of red cells which the untreated 

 serum had failed to agglutinate, but negative results occurred in every 

 instance. 



Specific Agglutinins. 



The technique adopted for these investigations has been similar to that 

 referred to in detail in the previous reports. The experiments connected 

 with specificity have so far been of a confirmatory nature, that is, if a serum 

 is saturated with suitable red cells, the agglutinative property of the serum 

 is removed for those red cells, but remains for other red cells which were 

 agglutinated by the serum })revious to saturation, although exceptions very 

 occasionally occur. Th(^ following experiment well illustrates this true 

 specific action. 



Immune serum (pneumonia) + normal red cells = marked agglutination. 

 Immune serum (pneumonia) + immune red cells (pernicious anaemia) = 

 nuirked agglutination. 

 The immune serum was then saturated with normal red cells for two and 

 a quarter hours at 37° C. and then centrifugalised at high speed. 



Resulting clear fluid + normal red cells = no agglutination. 

 Eesulting clear fluid + immune red cells (pernicious aiijemia) = marked 

 agglutination (as before). 



It is interesting to note here that in the series of experiments with normal 

 blood, when marked agglutination of the red cells 'occurred with the serum 

 of another normal person, similar speciflcity could definitely be demonstrated. 



Heated Red Cells. — In the ' Proceedings of the Royal Society '* a few 

 observations were made as to whether heated red blood corpuscles still 

 retained their specific properties. In these experiments it was found that 

 thoroughly washed red cells heated at 60° C. for one hour were still capable 

 of removing the agglutinative properties of a serum, as was the case with the 

 uuheated cells. The technique adopted in these experiments has already 

 been given in detail. In those examples about to be referred to varying 

 ranges of temperature have been employed from 66° C. up to boiling point. 



We have found that red cells heated to a temperature of 66° C. for 

 one hour, or at 100° C. for half an hour, are still able to render a suitable 

 serum inactive when carried to the point of saturation. 



The following experiment will serve as an illustration : — • 

 * ' Roy. Soc. Proc.,' B, vol. 81, p. 214. 



