PREFACE. 



My interest in an opportunity to study the subject of snake venom I owe 

 to certain peculiar and fortunate circumstances. After my graduation in 

 medicine, I was for several years connected with the Institute for Infectious 

 Diseases, in Tokio, where I came under the instruction of Professor Kitasato. 

 In the autumn of the year 1900 I became assistant in pathology at the Uni- 

 versity of Pennsylvania, where I remained until Professor Flexner resigned his 

 post to assume the directorship of the laboratories of the Rockefeller Institute. 

 It was soon after my arrival in Philadelphia that Dr. S. Weir Mitchell 

 expressed his great desire that the scientific study of snake venom should 

 be resumed and prosecuted along the Hnes of the new biological conceptions 

 of toxication and immunity, which had become at that time so promising a 

 field of pathological investigation. I had, therefore, the good fortune thus 

 early to become associated in carrying out the studies (which extended 

 over several years), relating to snake venom, which were issued from the 

 pathological laboratory of the University of Pennsylvania. The expenditure 

 involved in the execution of the researches of snake venom was met first by 

 Dr. Mitchell himself, and later, chiefly through his recommendations, by 

 means granted from the Bache Fund of the National Academy of Sciences 

 and by specific grants from the Carnegie Institution of Washington. 



During the several years of my connection with the University of Penn- 

 sylvania, I was the recipient of many courtesies from the other members of 

 the staff of the Pathological Department, and from Provost Harrison, Dr. 

 John Marshall, the professor of chemistry, and many others, to whom I wish 

 to express my appreciation. In the interval between my leaving the Uni- 

 versity of Pennsylvania and resuming my connection with Professor Flexner 

 at the Rockefeller Institute, I spent a year of study on snake venom at the 

 Statens Serum Institute, in Copenhagen. The expenses incurred were de- 

 frayed by the Carnegie Institution of Washington. For the opportunity 

 to continue my work in the Serum Institute I am indebted to Dr. Madsen, 

 who has also placed me under many obligations by his constant aid and 

 kindness. I am also indebted for many courtesies to Professor Salomonsen 

 and to Dr. Walbum of the Institute. 



The present monograph on snake venom was projected a number of years 

 ago, and at first it was intended that it should be devoted to a collection of 

 the studies on venom in which I was more or less directly concerned. The 



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