24 g TEXT-BOOK OF PHYSIOLOGY. 



the scale corresponds to that of normal blood. If, therefore, the 

 colors are identical at 75 divisions, the blood contains but 75 per 

 cent, of hemoglobin. 



Very frequently the diminution of corpuscles and hemoglobin 



FIG. 103. VON FLEISCHL'S HEMOMETER. K. Red colored wedge of glass moved 

 by R. G. Mixing vessel with two compartments, a and a'. M. Table with 

 hole to read off the percentage of hemoglobin on the scale P. T. To move K. 

 S. Mirror of plaster-of-Paris. 



proceeds along parallel lines, in which case the amount of hemoglobin 

 per corpuscle is supposed to be normal and the color-index = i. 

 If the hemoglobin diminution is greater than the corpuscles, as is 

 the case in many pathologic conditions, the color-index is less than 

 unity. If the percentage of corpuscles is determined by the method 



of counting to be 80 per cent. 

 (4,000,000 per cubic milli- 

 meter) and the percentage of 

 hemoglobin 60, the color- 

 index is obtained by dividing 

 the latter by the former; e. g., 

 f-g- = 0.75. In other words, 

 each corpuscle has but 0.75 

 per cent, of the normal 

 amount of hemoglobin. 



Absorption Spectra. Both oxyhemoglobin and reduced hemo- 

 globin, like other soluble pigments, have an absorbing influence on 

 certain waves of light, and hence give rise to absorption bands which 



FIG. 104. TINTED GLASS WEDGE OF THE 

 VON FLEISCHL HEMOMETER. (Da 

 Cosla's Hematology) 



