70 Messrs. Dudgeon and Wilson. On the Presence of [Sept. 11, 



Immune pneumonic serum when added to normal red cells produced 

 marked agglutination, but when added to the auto-red cells no effect was 

 produced. Two samples of each type of red cell were placed in suitable 

 sealed glass tubes and heated (i) at 95° C. for .30 minutes, (ii) at 63° C. for 

 one hour. The same immune serum was then saturated with these red cells 

 for 12 hours at 37° C, the clear fluid obtained from each mixture after 

 ceutrifugalisation had been completed was added to normal red cells and 

 the pneumonic red cells as in the experiments previous to saturation ; it was 

 now found that the clear fluid obtained after tlie immune serum had been 

 saturated with the normal red cells at both ranges of temperature failed to 

 agglutinate normal red cells. In another instance red cells which had been 

 exposed to a temperature of 100° C. for 30 minutes were capable of 

 removing the specific agglutinative action of a certain serum, and this result 

 could be shown to be strictly specific. 



Dried Red Cells. — It was thought possible that, as red cells which had been 

 exposed to high temperature were still capable of exerting their specific 

 action, similar results might be obtained with dried red cells. The tetihnique 

 adopted in these experiments was as follows : — 



Various samples of citrated red blood corpuscles were thoroughly washed 

 in normal saline, and then freed as far as possible from saline. The thick 

 suspensions of the various red cells were placed in watch-glasses and dried in 

 a partial vacuum over chloride of calcium, tlie entire process of drying 

 lasting some 12 to 24 hours. The dried blood was then pounded in an agate 

 mortar to a fine brick-chist powder ; samples of sei-a were then saturated with 

 these dried and pounded red cells. The technique for tlie experiments on 

 saturation was similar to' that already referred to with the heated red cells, 

 and the results were likewise similar, that is to say, red cells thoroughly 

 dried and pounded were still capable of preserving their specific functions, as 

 this experiment will server to illustrate. 



A mixture of normal serum and jaundiced red cells gave rise to marked 

 agglutination ; this S(num, wlum saturated with th(!se dried and pounded red 

 cells, was no hmger capal)l(^ of agglutinating them, but it was still abh^ to 

 agglutinate other saiiii)l(is oi' red cells which it hiui been a,hl(i to do pnwious 

 to saturation. 



S'f/id. — Since r(!(l cells which ha,v(; luien exposed lo tli(\s(' high l,(Mn])ei'atures 

 althougli so })hysi('.ally alU!r(Ml ani still caj^alilc of <'xerting a specific 

 agglutinative action, it was thought thul^ saiul heated to a siniilai' l(;niperaLure 

 might give ris<! to icUiUtiral results, but it Wiis found IVoni (>xpeiiniental 

 observations to lie inert. 



