VI PREFACE. 



strength for definite times^ to enable even a beginner to arrive 

 at an average result without loss of time in experimenting. 



It is therefore hoped that the usefulness of the work as 

 a compact and inexpensive book of reference for the expe- 

 rienced worker, as well as a guide to those commencing 

 investigations, may justify its publication. 



Very few "double-stains" have been given, as even when 

 good results could be obtained by using two dyes in the same 

 solution, better and more precise staining was effected when 

 the same dyes were used separately one after the other. 



Amongst the stains but little known, which have given 

 very good results, may be mentioned Benzopurpurine as 

 a counter-stain to Hsematoxylin ; Congo Red for the central 

 nervous system ; and Rose Bengale for the detection of early 

 Amyloid. The last reaction has not been previously noticed. 



For the pathological work, the co-operation of F. J. 

 Warwick, M.B. (Cantab), a practical microscopist of much 

 experience in this subject, has been most valuable. 



Most of the methods given under Micro-organisms have 

 been translated from the original papers. Kiihne's methods 

 are taken from the translation by Dr. Vincent Harris. 



P. W. S. 



413, OXFORD STBEET. 

 April o, 1892. 



