XIV PREFACE 



In July, 1908, I obtained the appointment of Patho- 

 logist to the Royal Southern Hospital at Liverpool, 

 which I held for eight months, during which I was 

 able to investigate further the laws of the diffusion of 

 substances into living cells and to devise the technics 

 for the determination of the "coefficient of diffusion." 

 In the meantime I published the results of work done 

 while I was in Egypt. This could not be done before, 

 because Mr. Graham would not permit me to publish 

 scientific work. Two papers appeared in The Journal 

 of Physiology in September, 1908, four in The Lancet 

 in January and February, 1909, and that on the " Co- 

 efficient of Diffusion" in the Proceedings of the Royal 

 Society in April, 1909. 



In August, 1908, I was demonstrating the excita- 

 tion of amoeboid movements caused by atropine to 

 Dr. Macalister, when he suggested to me that possibly 

 there might be some alkaloid-like excitant in the blood 

 of cancer patients; and this important suggestion was 

 the starting-point of the investigation of cancer by this 

 in-vitro method. Dr. Macalister and I read a paper 

 before the Royal Society of Medicine in November, 

 1909, on the researches which immediately followed his 

 suggestion. 



In March, 1909, Professor Harvey Gibson also sug- 

 gested the important point, based on an observation 

 made by Professor Farmer, that nuclein might have 

 some influence on cell-division. I must acknowledge 

 the great assistance which I have received from Pro- 

 fessor Harvey Gibson on many occasions, as well as 

 the loan of a well-equipped laboratory in the Hartley 



