284 



SCIENCE 



[Vol. LV, No. 1420 



newspaper clippings, magazine articles, articles 

 from technical periodicals, etc. Priority 

 throughout is given to original sources of in- 

 formation, including any and all official re- 

 ports, documents, etc., of value. Aside from 

 the foregoing, there is a section on Graphics, 

 which is becoming a matter entitled to 

 separate consideration, on account of the 

 growing demand for graphic publicity of social, 

 medical and economic experience. As thus con- 

 ceived, the organization of knowledge can be 

 brought within the compass of six general divi- 

 sions, which can easily be memorized and into 

 which numerous special sub-divisions fit auto- 

 matically on the principle of associated ideas. 



Feedeeick L. Hoffman 

 Prudential Insurance Company 

 OP America 



Newark, N. J. 



AMERICAN BIOLOGICAL STAINS 



COMPARED WITH THOSE OF 



GRUBLER 



In a recent article^ the writer called atten- 

 tion to the need of standardizing biological 

 stains now that those of American manufac- 

 turers are on the market. In this article men- 

 tion was made of the fact that the American 

 stains had a rather bad reputation among bio- 

 logists not necessarily because of their actual 

 poor qualities, but merely because they are dif- 

 ferent from the Griibler stains which were 

 standard before the war. It was stated at this 

 time that the Society of American Bacteriolo- 

 gists was beginning an investigation of the 

 American stains, and the cooperation of other 

 scientific bodies was urged. Since the article 

 in question was wi'itten much cooperation of 

 this kind has been secured and the work has 

 been put on a much broader basis. For this 

 reason it seems well at the present time to in- 

 sert in these pages a brief report on progi'ess, 

 particularly since many interesting results have 

 already been obtained in comparing the various 

 brands of stains. 



Still more recently there appeared in this 



1 H. J. Conn, The Production of Biological 

 Stains in America, Science, N. S., 53: 289-290. 



journal^ a statement as to a project of the 

 National Research Council on the standardiza- 

 tion of biological stains. This work of the 

 National Council is the out-growth of the in- 

 vestigations already made by the bacterio- 

 logical society. Several of the national scien- 

 tific organizations, notably the Botanical So- 

 ciety of America and the American Society of 

 Zoologists, are already taking active part in the 

 work. As a result there are now some forty 

 bacteriologists who have taken part ^ in the 

 bacteriological tests of the stains, about fifteen 

 zoologists who are examining certain stains for 

 eytological and other histological work, and it 

 is expected shortly to have a similar group of 

 botanists taking part in the work. The hearty 

 cooperation of all of these investigators, lo- 

 cated in many different institutions all over the 

 country, is one of the most pleasant sui'prises 

 the work has brought out. The tests involved 

 are often quite time-consuming and the willing- 

 ness of the collaborators to carry them out 

 without question of remuneration or credit for 

 the work is felt to show that biologists in gen- 

 eral are keenly interested in the subject. With- 

 out their eager cooperation the work would have 

 been impossible, and much credit is due to all 

 of them. 



The work has brought out quite plainly that 

 three series of tests are necessary in standardiz- 

 ing any particular stain : first it must be tested 

 for bacteriological staining; second for histo- 

 logical staining; and third its chemical com- 

 position must be determined so far as the pres- 

 ent status of dye chemistry makes this pos- 

 sible. At present three stains or groups of 

 stains have been tested from the bacteriologi- 

 cal standpoint : f uchsin, methylene blue, and 

 the gentian and methyl violets. Of these, 

 methylene blue and gentian violet are now be- 

 ing tested in histological work. In addition 

 to these, histological tests are being made of 

 safranin, hasmatoxylin, orange G and eosine. 

 Chemical work, through the cooperation of the 

 Department of Agriculture in the Color Labora- 

 tory, under Dr. Ambler, has been done on 

 methylene blue, and similar tests are shortly 



- The Standardization of Biological Stains, 

 Science, N. S., 53: 2S9-290, 1921. 



