COLOR CHART OF INDICATORS 



REPRINTED FROM 



The Determination of Hydrogen Ions 



by 

 WM. MANSFIELD CLARK, Ph.D. 



Are Now Available as a Separate 



EXPLANATION 



The colors shown upon the chart were reproduced from tubes 16 

 mm. internal diameter containing 10 cc. standard buffer solution. The 

 quantities of indicator solution added in each case were as follows: 



Thymol blue, acid range (T.B. acid range) 1 cc. 0.04 



per cent solution 

 Brom phenol blue (B.P.B.) 0.5 cc. 0.04 



per cent solution 

 Methyl red (M.R.) 0.3 cc. 0.02 



per cent solution 

 Brom cresol purple (B.C.P.) 0.5 cc. 0.04 



per cent solution 

 Brom thymol blue (B.T.B.) 0.5 cc. 0.04 



per cent solution 

 Phenol red (P.R.) 0.5 cc. 0.02 



per cent solution 

 Cresol red (C.R.) 0.5 cc. 0.02 



per cent solution 

 Thymol blue (T.B.) 0.5 cc. 0.04 



per cent solution 



It must be remembered that the light adsorptions in the case of the 

 standard solutions and in the case of the printed colors are quantitatively 

 very different in the two cases. Therefore, the user of the chart will 

 have to use discretion and should consider the printed colors to be only 

 rough standards. 



Williams & Wilkins Company 

 Publishers of Scientific Journals and Foo'is 

 Baltimore, Md., U. S. A. 



Gentlemen: I or We enclose S for: 



One copy of the Chart $1.00 a copy 



Three copies of the Chart 90 a copy 



Five copies of the Chart 75 a copy 



Ten copies of the Chart 65 a copy 



Fifteen copies of the Chart 60 a copy 



Twenty-five copies of the Chart, or over 50 a copy 



of the Color Chart of Indicators reprinted from Clark's "The Deter- 

 mination of Hydrogen Ions." 



Signed 



Address 



