August 11, 1922] 



SCIENCE 



157 



the investigation of the biological stains pro- 

 duced in this country. This committee is work- 

 ing in cooperation with the Society of Amer- 

 ican Bacteriologists, the Botanical Society of 

 America and the American Society of Zoolo- 

 gists. Through the cooperation of these dif- 

 ferent organizations stains are being tested in 

 their bacteriological applications, and in their 

 histological and cytological uses, bo4:h in con- 

 nection with zoology and botany. The field is 

 a very large one and in some lines the work is 

 only just barely started; but enough informa- 

 tion has been obtained in connection with cer- 

 tain uses of some of the stains so that a pre- 

 liminary report is justified at the present time. 



The most important conclusion reached in 

 this work is that in general as good stains can 

 be obtained in this country now as were avail- 

 able before the war. In some eases the Amer- 

 ican products are distinctly better than were 

 the Griibler stains. The only important stains 

 we have so far failed to find in satisfactory 

 quality in this country are methyl green and 

 safranin. In regard to these it must be men- 

 tioned that not all Griibler samples were satis- 

 factory, some of the samples we have tested 

 which were of unquestionable Griibler origin 

 proving as unsatisfactory as the poorest Amer- 

 ican samples. It must be remembered that 

 Griibler did not manufacture stains, but bought 

 from other concerns in large quantities, and 

 the constancy of his stains was due wholly to 

 the large bulk he was able to buy at once, on 

 account of the large market which he supplied. 

 In general his stains were in no sense pure, 

 and one of the greatest difficulties in this coun- 

 try at present is that as soon as a biologist 

 obtains poor results with a stain he immedi- 

 ately cSUs for a purer product, which the man- 

 ufacturer tries to supply, often obtaining 

 stains that are too pure to be used by the same 

 formuliB originally used with Griibler stains. 

 It is not purity so much as agreement with the 

 Griibler products in staining properties that 

 should be desired. 



It is hoped that eventually one line of stains 

 may come to have official approval in this 

 country, not necessarily all manufactured by 

 the same house but the production of each 

 stain limited to one concern, so that responsi- 



bDity of its manufacture can be definitely fised. 

 Arrangements for this have not yet been made 

 and can not be until more preliminary inves- 

 tigation has been can-ied on, but at the present 

 time it is possible to recommend certain brands 

 of the most common stains for certain par- 

 ticular purposes. 



METHYLEN BLUE 



There are various grades of methylen blue 

 on the market, but so far as we have been able 

 to find out, one grade, namely, the medicinal 

 grade generally designated as methylen blue 

 U.S. P., seems to be satisfactory for all pur- 

 poses. This is the purest grade of methylen 

 blue on the market and, although there ai-e 

 other grades of slightly less purity, designated 

 by such terms as "BX" or "rectified for blood 

 stains," which are perfectly satisfactory for 

 staining purposes, nevertheless the difference 

 in price between them and the medicinal grade 

 is insignificant. It is the committee's recom- 

 mendation, therefore, that methylen blue 

 U.S.P. be regularly specified. The following 

 brands have been very carefully tested for bac- 

 teriological purposes and prove to be very sat- 

 isfactory. Indications are that they can be 

 used equally well in histological work, although 

 for this pui-pose they have not been so fully 

 tested. These 'brands are: Coleman and Bell 

 Company, National Aniline and Chemical 

 Company and Providence Chemical Company. 



Of these three brands, the first and last men- 

 tioned have been tested in vital staining of 

 shrimps and sea worms. In this work quite 

 a large number of other methylen blues were 

 run for comparison. Of those tested, the sam- 

 ple of medicinal methylen blue from the Provi- 

 dence Chemical Company was the only Amer- 

 ican sample of known manufacture to compare 

 with Griibler's methylen blue for bacilli when 

 used for this purpose. Only one report on 

 the stains used in this way has been received, 

 but as it is by a specialist in this line of work 

 the results are regarded as quite conclusive. 



PUCHSIN, BASIC 



This stain has been tested for two different 

 purposes: (1) Staining bacteria, primarily the 

 tubercle organism; and (2) for use in the Endo 

 medium for differentiating the colon and 



