216 



Mr. L. S. Dudgeon. On the Presence of [Feb. 18, 



only, is it possible for the cells to reach the temperature indicated by the 

 thermometer. We know that it is stated that if a serum is heated to 65° C, 

 it loses certain properties which the unheated serum possesses ; as a matter of 

 fact, if human serum is kept at the temperature of 65° C. for 15 minutes in 

 the manner indicated, it is rendered useless for serum investigation owing to 

 the fact that it is coagulated. 



In the experiment about to be referred to, certain immune red cells were 

 heated at 60° C. in the manner indicated for 50 minutes, and at the end of 

 that time formed a thick dark mass. Pneumonic serum and these red cells 

 gave a high degree of agglutination before saturation, but after the serum 

 had been saturated with the heated red cells for one and a quarter hours at 

 37° C, it was rendered inactive. This shows that, although the red cells 

 were physically so altered, yet they still possessed a specific functiou. Similar 

 results were obtained in another series of experiments in which the red cells 

 were heated to 60° C. for one hour. 



The Relation of the Bacterial and Hwm-aggtviinins. 



Several series of experiments have been completed, and the results clearly 

 demonstrate that the bacterial and hasm-aggiutinins are distinct. Typhoid 

 serum, especially a serum possessing high agglutinative properties, is 

 especially suitable for the purpose. 



As will be seen from the accompanying table, the highest degree of 

 specificity exists, and every experiment gave similar results. The saturation 

 experiments were carried out in every detail in an identical manner. 



Phagocytosis. 



In summarising the technique and the results of the experiments on 

 phagocytosis in my preliminary paper, it was stated that " It is unnecessary 

 to refer at great length to the very large number of experiments made, as it 

 was only in a few instances that phagocytosis was pronounced. In quite 

 a number of instances, whether the serum was unheated, or diluted, or heated, 

 or whether normal or immune leucocytes were employed, the degree of phago- 

 cytosis was infinitesimal." There was only one instance out of the total 

 number investigated in which the phagocytosis of red blood corpuscles was 

 a conspicuous feature. In the present communication striking instances of 

 red cell phagocytosis have been recorded on several occasions, these different 

 results mainly depending upon the nature of the diseases which are now 

 being investigated. It is especially marked in such acute diseases as typhoid 

 fever, while in pernicious anaemia, where it might be expected to occur, it is 



