PREFACE. 



THE exigencies of tropical practice require most 

 medical men to be practical sanitarians as well as 

 clinicians. 



It is with this in view that in the present work, while 

 due attention has been paid to the clinical features, treat- 

 ment and nursing of tropical diseases, speciaj prominence 

 has been given to their etiology and prevention. 



Owing to the recent advances in the knowledge of the 

 etiology of many tropical diseases the subject of their 

 prophylaxis is a very promising one, since the general 

 principles on which efficient and economical preventive 

 measures should be based are now well understood. 



In the application of such general principles local 

 conditions must be carefully considered, and thus in 

 describing the various methods to be adopted those 

 suitable for certain localities have been given as types. 



In the spread of many tropical diseases intermediate 

 hosts play an important part, and the life-history of such 

 hosts, often insects, has been considered at some length, 

 as a knowledge of this subject is essential to the proper 

 understanding of the rationale of the preventive measures 

 proposed. 



An attempt has been made to group the diseases treated 

 of according to their known or probable causation. 

 Thus, in the first part those diseases are dealt with which, 

 like Malaria, are known to be due to Protozoa, and others, 

 such as Yellow Fever, which are probably due to such 

 organisms. 



In the second part diseases due to the higher forms 

 of animal life are considered. 



