Foreword to Part II 



Part I of this book described the 

 methods of making microscope shdes and 

 contained specific information as to tech- 

 nicjues and formukis onh' in the typical 

 preparations which were appended to each 



tains specific information both as to tech- 

 niciues and formnkis, but does not give 

 general instructions as to the preparation 

 of the sUdes except in a few typical prepa- 

 rations inserted into Chapters 20, 21, and 



chapter. This second part of the book con- 23, which deal with staining. 



Classification 



The 3500 specific formulas and methods 

 which follow have been arranged accord- 

 ing to a system of classification designed 

 to bring similar methods and formulas to- 

 gether, and to make it easy for the worker 

 to find that which he requires. 



The primary division of this mass of 

 material has' been into chapters; within 

 each chapter there is a decimal division of 

 the contents. Each chapter is designated 

 by one, two, or three letters which indi- 

 cate the nature of the formulas and tech- 

 niques contained in it. Thus, DS stands 

 for dye stains, ADS for accessory dye 

 stains, and so on. The complete decimal 

 classification emploj'ed in each chapter is 

 given at the beginning of each chapter, 



and, for purposes of cross reference, each 

 formula or method is assigned the letter 

 of its chapter and its own decimal designa- 

 tion. Thus a reference to DS 11.41 indi- 

 cates division 11.41 of Chapter 20. The 

 addition of the author's name and date 

 to the decimal classification renders clear 

 the identity of the method referred to, and 

 permits it to be given in the least possible 

 space. By this method it has been possible 

 to ensure that no formula for a solution is 

 given more than once, and that each solu- 

 tion is placed with other solutions of 

 similar composition or properties. The 

 method by which journal references have 

 been added to these designations is ex- 

 plained in the Introduction. 



Measurements and Units Employed 



With the exception of the fixatives 

 (Chapter 18) all formulas for solutions 

 have been adjusted to give approximately 

 100 parts. The fixatives have been ar- 

 ranged to give either 250 parts when pre- 

 pared from pure reagents, or 100 parts 

 when prepared from the stock solutions 

 described in the second part of Chapter 

 18. This exception, in the case of the fixa- 

 tives, has been made since the writer has 

 convinced himself, by inquiring among 

 numerous workers, that 250 milliliters is 

 the quantity of fixative most frequenth' 

 prepared. 



It is to be presumed, in the preparation 

 of all the solutions, that fluids ai'e meas- 

 ured by volume and solids by weight. The 



words milliliter and gram have, therefore, 

 l:)een omitted since their inclusion would 

 have added 30 or 40 pages to the total 

 length of the book. In a few cases where 

 the context does not make it entirely 

 clear that fluids are to be measured in 

 volumes and solids by weight, the ap- 

 propriate units have been given. 



Saturated solutions are assumed to mean 

 saturated solutions at room temperature, 

 unless otherwise specified. It is also to be 

 understood that the solvent of a saturated 

 solution is water unless a specific state- 

 ment to the contrary is made. In a few 

 cases which might cause confusion, as in 

 the case of dyes which are equally fre- 

 cjuently dissolved in alcohol or water, the 



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