8 Preface to First Edition 



mittee representing the American Chemical Society, the American 

 Society of Bacteriologists, the Society of American Zoologists, the 

 Botanical Society of America, the American Association of Pathol- 

 ogists and Bacteriologists and the American Association of 

 Anatomists. It has a membership of about sixty biologists, 

 members of the various societies just mentioned, who assist in the 

 examination and testing of stains, each in those particular lines 

 of technic with which he is especially familiar. It has secured the 

 cooperation of chemists, dye manufacturers and stain dealers, so 

 as to be sure that the needs of biologists can be immediately re- 

 flected in the supply of stains on the market. Its affairs are man- 

 aged by an executive committee of five members, the present 

 members of which represent bacteriology, botany, dye chemistry, 

 pathology and zoology, respectively. This executive committee 

 has undertaken the preparation of this book. The authorship of 

 the book has been assumed by the chairman of the committee, 

 however, in order to fix the responsibility and to make bibliogra- 

 phic references to it simpler than in the case of plural authorship; 

 but the assistance of the other committee members in the work 

 has been so great that they may be practically considered co- 

 authors of the book. The chairman of the committee, therefore, 

 wishes to take this occasion to acknowledge the invaluable assist- 

 ance given by these other members. Without their cooperation 

 such an undertaking would have been impossible. 



The chief object of the book is to present in logical form the 

 information which has been accumulating in the hands of the Com- 

 mission since it was organized. It is neither a treatise on dye 

 chemistry nor one on microscopy; although it contains information 

 in both fields. It is an effort to present in a form acceptable to 

 biologists the principles of dye chemistry so far as they have a 

 bearing on biological stains; and to discuss the suitability of the 

 different dyes for various biological purposes, presenting data 

 partly original and partly drawn from the literature. The sub- 

 ject matter is realized to be incomplete, particularly that part of 

 it which deals with the biological uses of dyes. An effort has been 

 made to list the most important present uses of stains, and of the 

 obsolete uses to mention those of historical significance; but it is 

 realized that there must be many omissions. It is hoped that 

 readers of the book will cooperate by calling to the author's at- 

 tention places where the treatment of any subject seems in- 

 adequate. 



H. J. Conn, Chairman, 

 Commission on Standardization 

 of Biological Stains. 

 Geneva, N. Y., 1925 



