INVESTIGATION OF AMERICAN STAINS 



133 



When used in the endo medium, the samples were reported 

 quite differently. The result plainly depends on the technic, 

 some methods calling for too concentrated a solution of the dye 

 to be decolorized by the amoimt of svdfite ordinarily used. The 

 following formulae were used : 



Meyers: 0.5 cc. of 10 per cent alcoholic fiiclisiii added to 10 oc. of 2.5 per cent 

 sodium sulfite solution. Tlli^^ quantity added to 100 cc. of the agar. (Stand- 

 ard method of .Vmerican Public Health .Vssnciation.) 



TABLE 2 

 Summorii of reports onfuchsin; samples arranged in order of excellence 



Castlemaii, first test: 1 cc. of saturated alcoholic fuchsin added to enough 10 



per cent sodium sulfite solution to decolorize. One cubic centimeter added 



to 100 cc. of agar. 

 Casileman, second test: 0.5 cc. of 1 per cent alcoholic fuchsin added to 1.5 cc. of 



2.5 per cent sodium sulfite solution. One cubic centimeter added to 100 cc. 



of the agar. 



The only sample giving universallj' satisfactory results in 

 these tests is that of the Coleman and Bell Company. This 

 finding has been corroborated by other results not included in 

 the present series of tests. By using the proper technic, how- 

 ever, i.e., either the first or the third formula above, good results 



