PREFACE ix 



to take part in " congresses " or to give special 

 addresses, and often stayed a day or two with me in 

 London.-^ I was with him at the DarwiQ Celebration 

 at Cambridge in 1909, and the last occasion when he 

 came was to give the Priestley Lecture of the National 

 Health Society in November 1912. At my request 

 he selected " The Warfare against Tuberculosis " as 

 his subject, and gave a most valuable account of the 

 history and actual condition of that enterprise, 

 relating the important results of his expedition to the 

 Kalmuk Tartars for the purpose of studying the 

 immunity from and the liability to infection by 

 tuberculosis among that nomad population. The 

 lecture was delivered in French, and I made a trans- 

 lation of it which appeared with numerous illustra- 

 tions in the journal called Bedrock, published by 

 Constable & Co. I mention that publication here 

 as it is the only one excepting the three lectures on 

 " The New Hygiene " (Heinemann, London, 1906) 

 originally published in an English form by Metchnikoff , 

 and deserves more attention from the English medical 

 public than it has received. 



I found Metchnikoff a delightful companion. He 

 always had something new or of special interest to 

 show to me at the laboratory — some microscopical 

 preparation, the digestive process in Protozoa, the 

 microbian parasite of a water-flea, a new method of 



^ He received an honorary degree at Cambridge in 1891, and also 

 attended the International Medical Congress in London in that year. In 

 1901 he gave a lecture at Manchester on the intestinal flora. In 1906 he 

 gave a course of three lectures in London on "The New Hygiene." I 

 translated them for him, and they were published as a little volume by 

 Heinemann. 



h 



