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



of the suspension of red blood corpuscles had taken place in any of the 

 individual sera before pooling, no effect was noted when the pooled serum was 

 added to the red cells. In a certain proportion of the samples of normal 

 blood examined for agglutinative properties a negative result was obtained ; 

 but some specimens, while not exhibiting true agglutination of the individual 

 chromocytes, showed a definite clumping of rouleaux. The appearance of 

 this type of agglutination was extremely rapid, and could be watched under 

 the microscope immediately after the specimen had been prepared. 



In another series of experiments the mixtures of the respective sera and 

 red cells were tested under special conditions of temperature; the blood was 

 collected in citrated saline at 37° C. and kept at that temperature ; tlie cells 

 were washed with saline also at 37° C, and the suspension of red cells was 

 made up in this warm saline, but these precautions did not appear to influence 

 the results in any way. 



Undiluted Bed Cells. — After the red cells had been washed in saline and 

 the supernatant fluid pipetted off, a mixture of one volume of serum and one 

 volume of undiluted red cells was made.. In one series of experiments the 

 5-per-cent. suspension of red cells gave no reaction with the appropriate 

 serum, l)ut when tested by this method perfect agglutination occurred 

 instantaneously. This experiment was the only instance in which such a 

 phenomenon was noted. In all other cases when negative results were 

 obtained by the 5-per-cent. red-cell suspension, similar results wei'e obtained 

 Ijy using the undiluted red cells. 



ffrrm-ne/glntinins. 



Tji the series of cases concerning this investigation ho instance of true 

 aut(j-agglutination has been mcit with, it lias bctni .shown that frequently 

 the serum or red cells of a patient suftering from a disease may agglutinate 

 or be agglutinate<l by the? red cells or serum of a patient sulfering from t he 

 same disease. 



Ill many instances it was f(jiiii(l that, by heating a scnim at 0()°('. I'or 

 15 minutes and thereby destroying its liniiolytic jiroixM-ty, the agglutinative 

 action was rendered mucli more obvious than previously, and this was 

 especially the case in tlios(; exani])les where the hicmolytic action was very 

 intense. In <jiie series of expeiiiiiciits (in haan-agglutiiiatioii neutral Ihiid 

 was used (0'8 per cent, sodium chlorich^ and 0-02 per cent, calcium chloride), 

 but no advantage; appeared to occur l»y eiiii)loyiiig a 5-j)(>r-ce)it. sus]»eiision of 

 red (;el]H in tliis Ihiid. 



Km tlici ati(Mn|its were niiulc to cxiiact liy|i()thetical agglutinins from the 

 red cflls 1 hcnisi'ht's. 'I'lic inntrnls nl' n - tube containing seniin and 



