PREFACE TO THE SECOND EDITION. 



THE fact of the necessity for a second edition of this manual of lab- 

 oratory and clinical diagnosis in a little more than a year would indicate 

 that the original arrangement of material should be adhered to. 



Each section of the book had been carefully revised and much new 

 matter added. In particular has that part of the book relating to ani- 

 mal parasitology been rewritten and almost doubled in extent, and a 

 chapter on Poisonous Snakes added. In the chapter on " Practical 

 Methods in Immunity" the most recent advances in the Wassermann 

 test and practical agglutination methods have been incorporated as well 

 as a brief discussion of the question of Anaphylaxis. 



The section on " Clinical Bacteriology and Animal Parasitology of 

 the Various Body Fluids and Organs" has been revised to meet the most 

 recent advances in clinical diagnosis. This section not only answers 

 as a cross index to the importance of the various bacteria and animal 

 parasites in practical clinical work, but gives a concise, practical state- 

 ment as to how to proceed in the examination of various secretions and 

 excretions. This information is difficult to obtain in the larger works 

 on clinical diagnosis by reason of its being taken up under many different 

 headings. 



A method is given for the making of differential counts in the same 

 preparation as that for making the leukocyte count which has the advan- 

 tages of accuracy and the saving of time. 



Several new illustrations have been added the one of poisonous 

 snakes has been taken from Stejneger's report. 



The plan of making this little volume a practical one has been con- 

 tinued in the second edition; theoretical considerations have been 

 brought out only when necessary to a proper understanding of some 

 recent or difficult laboratory method. 



The very elementary considerations and definitions have not been 

 given because in order to present a compact and at the same time a 

 practical working guide it has been necessary to eliminate that which 



vii 



