128 H. J. CONN 



In order to survey the field it seemed necessary to test products 

 from as many sources as possible. As the whole field is a large 

 one, the attention of the committee at first was given to but 

 three stains or groups of stains; fuchsin, methylen blue, and 

 gentian violet. About thirty members of the Society, — to whom 

 much credit is due,^ — volimteered to assist. Their names are 

 given at the end of this paper; and without their hearty co- 

 operation, the work would have been impossible. Our study is 

 not complete yet, but a fairly satisfactory survey of the field has 

 been made, so far as concerns fuchsin and methylen blue. The 

 gentian violet situation is more complicated and further in- 

 vestigation is necessary. 



Upon looking into the commercial situation, it proved necessary 

 to obtain samples of the dyes from two different classes of dealers : 

 the basic dye manufacturers and the so-called "manufacturers 

 and standardizers " of biological stains. The former group are 

 the manufacturers of general textile dyes, and embrace such 

 concerns as the National Anilin Company, the duPont Com- 

 pany, the Calco Chemical Company, and Dicks, David and 

 Company. The latter group generally buy their dyes from the 

 former, make certain tests of them and put them on the market 

 as biological stains, with or -ftdthout modification; their chief 

 function is standardization rather than manufacture. Repre- 

 sentatives of the latter group are the Providence Chemical 

 Laboratories, the H. S. Laboratories, the Coleman and Bell 

 Company (formerly the National Stain and Reagent Company), 

 and the Heyl Chemical Company. Samples from these various 

 concerns were obtained through a jobber who had consented to 

 cooperate in the work. This was done so that no concern would 

 know the reason for which the samples were bought. To make 

 unbiased opinions still more certain, the samples were dis- 

 tributed among the various investigators bj'^ number only, 

 without reference to the names of the dealers. 



Throughout this work, the conunittee has been in corre- 

 spondence with all of the second group of dealers mentioned 

 above, and with the Calco Chemical Companj' as well. There 

 has seemed no purpose in getting in touch with the other basic 



