PREFACE TO FIRST EDITION 



When microscopists first began, 'in the sixties and seventies, to 

 use stains, the demand for dyes for this purpose was naturally too 

 small to justify a special source of supply. They therefore had to 

 make use of textile dyes, which were then very crude and were 

 not constant in their composition. After a number of years, 

 however, the demand for biological stains grew and a special com- 

 mercial source of supply for them first appeared in Germany. 

 This was the Dr. G. Grubler and Co. This company did not 

 manufacture the dyes, as used commonly to be thought in other 

 countries; but on the other hand it cannot be denied that its 

 founder made a distinct contribution to science in making the 

 first effort to secure constancy and reliability in dyes intended 

 solely for the use of the microscopist. It is supposed that he 

 tested dyes under the microscope himself, and if a batch proved 

 satisfactory in his experience bought a supply large enough for a 

 number of years, bottled it under his own label and sold it to 

 biologists. There is no question but that in this way the biologist 

 was furnished with a much more reliable line of stains than if he 

 had been obliged to buy directly from the dye manufacturers; but 

 it was an empirical method of standardization and there was 

 nothing to prevent different batches of some dye secured by this 

 company from varying considerably in their composition. Such 

 upon investigation has proved to be the case. 



Although a great service was done to biologists by this company 

 in the latter part of the nineteenth century, such methods of 

 standardization are not in keeping with modern scientific knowl- 

 edge. A recent cooperative undertaking has therefore been or- 

 ganized in America to put the standardization of stains upon a 

 scientific basis. This undertaking started after the war had 

 caused a shortage of stains, with the object of securing a reliable 

 supply when the foreign sources were unavailable. It has since 

 then been widened in its scope; and now that the foreign products 

 are again available, the purpose of the work is to effect a scientific 

 standardization of stains whether derived from foreign or domestic 

 sources. As a matter of fact, so far only domestic samples have 

 been considered. This has not been because of any prejudice 

 against foreign stains, but because of practical diflSculties; it is, in 

 brief, difiicult to test each batch before it is put on the market 

 when the concern handling it is in Europe. 



The organization through which this work is being carried on is 

 known as the Commission on Standardization of Biological Stains. 

 It was organized in 1922 under the auspices of the National Re- 

 search Council and is still affiliated with it, although now no longer 

 a part of the larger body. It is in effect a coordinating com- 



