406 



Messrs. Dudgeon, Pantoii, and Wilson. [Apr. 26, 



The quantities of homologous protein sufficient to neutralise the 

 precipitin in varying amounts of the same antiserum show some relationship 

 to the amount of antiserum. The quantities of homologous protein augment 

 with an increase in the amounts of antiserum, but whether the quantities of 

 homologous protein are directly proportional to the amounts of antiserum is 

 not ascertainable from the present data. The weights of the precipitates 

 formed when increasing amounts of antiserum interact with a constant 

 quantity of homologous protein insufficient to neutralise the whole of the 

 precipitin in the antiserum augment with the amounts of antiserum, but the 

 weights of the precipitates from each unit of antiserum diminish as the 

 amounts of antiserum increase (Table III, tubes Nos. 10, 11, 12, and 13). 



The weights of the precipitates from 1 c.c. of different antisera are of value 

 in showing the order of magnitude of the weights of precipitin taking part in 

 precipitin interactions. 



In conclusion, I beg to express my indebtedness to Prof. Anderson Stuart, 

 in whose laboratory this research was carried out. 



The Injiuence of Bacterial Endotoxins on Phagocytosis. 

 (Preliminary Keport.) 



By Leonard S. Dudgeon, P. N. Panton and H. A. F. Wilson. 



(Communicated by Dr. F. W. Mott, F.R.S. Received April 26,— Read 



June 2, 1910.) 



(From tlie Pathological Ijaboratories, St. Thomas's Hospital.) 



These investigations were undertaken for tlie purpose of determining the 

 ■effect of endotoxic substances on phagocytosis,'as tested in vitro. Experiments 

 were made to determine whether these substances, when added to a phagocytic 

 mixture, would cause an increase or a decrease in the phagocytic activity ; 

 whether such action would be general or specific ; whether the action would 

 he affected by subjecting the endotoxins to varying degrees of temperature, 

 .;uid whether the toxins would act directly on the bacteria, the serum, or the 

 leucocytes. 



The present communication is intended only for the purpose of introducing 

 our preliminary results, which are derived from a considerable amount of 

 experimental enquiry. The explanation of the mode by which the effects to 

 be described are produced is now under investigation. 



