CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 



No. 3094. 



NO. 3098. 



Nos. 3100-4 



No. 3102. 



3094. COLORIMETER, Schreiner's, as used in the Laboratory of the Bureau of Soils, United States 



Department of Agriculture. All parts of the instrument which come in contact with the solu- 

 tions are of glass. The Colorimeter consists essentially of two graduated glass tubes which 

 contain the standard and the unknown colorimetric solutions, with two smaller glass immersion 

 tubes by means of which the length of the column of liquid in the graduated tubes may be 

 changed. These tubes are mounted on the colorimeter stand by an improved method which 

 makes their adjustment exceedingly simple and permits a rapid and easy setting while the 

 comparisons are being made. Complete with graduated and plain tubes. (For full description 

 see Journal of the American Chemical Society, Volume XXVII, September 9, 1905, and Bul- 

 letin Xo. 31, United States Department of Agriculture, Bureau of Soils) $20.00 



3095. TUBES, Graduated, for No. 3094, with 100 scale divisions, 2 mm apart per pair 5.00 



3096. TUBES, Immersion, for Xo. 3094, 26 cm long with polished bottoms per pair .90 



3098. COLORIMETER, Ukena's Comparator, widely used in determining carbon and manganese in iron 



and steel by the Eggertz method. Complete with stand, ground glass plate, and 10 Eggertz 

 carbon tubes with ground stoppers, graduated to 30 cc in i{ cc divisions 35.00 



3100. COLORIMETER, United States Geological Survey Standard Outfit, for determining color in watel 

 analysis. The method consists in comparing the color of the water under examination with 

 that of a series of glass disks, rated in color values according to the platinum-cobalt scale of 

 parts of platinum per million. Colorimeter complete with 4 aluminum tubes, one with clips for 

 holding disks, and others respectively 50, 100 and 200 mm long, for holding water to be tested; 

 six standard disks of amber colored glass mounted in aluminum; in compact morocco covered 

 case. (See Bulletin 151 of the United States Geological Survey) 38.50 



3102. TURBIDITY SCALE, United States Geological Survey Standard, made of aluminum, 8 inches 

 long and graduated in parts per million. To one end is attached a tape 4 feet long, similarly 

 graduated. Into the other end is fastened a nickel-plated brass screw eye containing a piece of 

 rolled platinum wire to be viewed. The depth of its disappearance to the eye indicates the 

 turbidity. Complete in case. 7.50 



3104. COLOR AND TURBIDITY OUTFIT, consisting of Nos. 3100 and 3102, combined in morocco cov- 

 ered case . 45.00 



