160 APPLICATION TO CANCER RESEARCH 



similarly tested, and it was found that the leucocytes 

 of healthy people bathed in the plasmata of cancer 

 patients undoubtedly showed amoeboid movements 

 which were exaggerated and different in character from 

 those which were observed in the corpuscles suspended 

 in the plasmata of normal persons, or of persons 

 suffering from a number of other diseases. The differ- 

 ence was one of degree, however, for leucocytes fre- 

 quently under these conditions showed some amoeboid 

 movements; but we were quite satisfied that there w T as 

 a distinct difference, although the test could not be 

 considered a very delicate one. 1 



This series of experiments made us consider that 

 there probably is some agent in the body fluids 

 of cancer patients which causes excitation of cells, 

 and one of us was charged with the task of further 

 confirming the correctness of this observation, and 

 of finding out what the substance is and how it is 

 produced. It was appreciated that this substance 

 could only be present in the blood in small concen- 

 tration, and that to isolate it from serum would prove a 

 very difficult task. 



As a preliminary to this part of the research, it 

 was considered advisable to review the known facts 

 concerning cancer to see whether they harmonised 

 with the possibility of the disease being associated 

 with an excitation of cells by chemical agents. After- 

 wards we proceeded, by means of the new jelly method, 

 to try the effects of different substances either taken 



1 A paper by Dr. Macalister and myself describing these experiments was 

 read before the Royal Society of Medicine in November, 1908. 



