218 



Dr. A. E. Wright and Staff- Surgeon S. T. Eeid. [Oct. 21, 



Dilutions in which .Che serum wets tested. 



Curve 3. 



Fallacy which may be introduced by the exposure of the Serum for a different 

 period to different degrees of Temperature. 



In view of the research of Dreyer,* which brought out the fact that the 

 agglutinating power of a serum may, as progressively higher temperatures, or 

 as the case may be progressively longer exposures are employed, be first lost 

 and afterwards recovered, it suggested itself that an analogous effect might 

 possibly be exerted upon the incitor element of an immune serum when 

 exposed for different periods to different temperatures. 



The results of a typical experiment carried out with such a serum are 

 embodied iu the Curve 4 below. 



It will be seen that while the incitor power of the immune serum was in 

 each case preserved, a very different phagocytic count was obtained according 

 as the serum was exposed to temperatures of 50°, 55° and 60° for a shorter 

 or longer time. 



It will be manifest, in view of these results, that where experiments are 

 conducted with heated sera care must be taken to see that in every case 

 the same conditions are observed in the matter of the heating of the serum. 

 * ' Brit. Med. Journ.,' September 10, 1904. 



