Uses and Standardization of Stains 11 



then to Hill (1770); while now Lewis (I.e.) quotes from a letter 

 written by Leeuwenhoek to the Royal Society in 1714 (published 

 1719) in which he mentions staining sections of muscle fibers in 

 saffron to increase the visibility of the particles as viewed under 

 one of his high power lenses. 



One can never be certain how long any particular individual will 

 remain credited with being the "first" to do something; but it is 

 difficult to see how the use of dyes in microscopy can precede the 

 invention of Leeuwenhoek's microscopes. 



Following the work of the pioneers in staining the development 

 of the subject was rapid, particularly after hematoxylin had been 

 introduced by Waldeyer (1863) and more successfully by Bohmer 

 (1865), anilin dyes by Beneke (186i2) and alcohol differentiation 

 by Bcittcher (1869). 



Gierke (1884), in his historical discussion of staining, says that 

 the history up to his day was divided into three periods, each 

 occupying a decade. The first decade, the fifties, was char- 

 acterized by a few important but unrelated discoveries which 

 ended in the work of Gerlach — each investigator following up 

 accidental observations on the staining powers of carmine and the 

 other well known dyes of those days. After Gerlach's work, the 

 development of the technic in the sixties was more rapid and de- 

 pended less upon chance success by the individual investigator; 

 the effort was made to use similarly all the dyes and metallic colors 

 then available. The next decade would have had much less left 

 to develop in this line if it had not been that by this time the great 

 variety of anilin dyes were available and microscopists were con- 

 stantly finding new uses for them. Gierke wondered if there 

 would be any opportunity for equal development during the ten 

 years to follow his paper. 



That development did not stop in his day is well known. 

 Scarcely a year has passed without the introduction of some new 

 staining technic of considerable importance. Sometimes dyes 

 hitherto unknown to the biologist have been shown to be valuable 

 in bringing out some particular structure; at other times new com- 

 binations of dyes have proved of special value for other purposes; 

 while by other investigators it has been shown that old methods 

 used with modern refinements of apparatus and technic, may 

 bring out details not dreamed of by the early histologists. 



USES OF STAINS 



Only a brief summary of the uses of stains is given here. More 

 detailed citations are given under the discussion of the individual 

 dyes throughout this book. Certain very general texts of the sub- 

 ject are also useful; among those which have proved most valuable 

 sources of the information given in these pages are: Mann (1902), 



