THE BLOOD 



247 



drop by drop until the color of the diluted blood is exactly that of the stand- 

 ard. The division of the scale reached by the dilution will represent the 





FIG. 97. HALDANE'S MODIFICATION OF GOWERS' APPARATUS. 



relative percentage of hemoglobin. If this tint is not obtained until the 

 dilution reaches 100 divisions, the quantity of hemoglobin is normal. If 



FIG. 98. 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. Pinion to move K. S. Mirror of plaster-of-Paris. 



more water must be added, it is in excess; if less, it is diminished. If, for 

 example, the 20 cubic millimeters of blood from an anemic patient gave the 

 standard tint at 60 divisions, the blood contained but 60 per cent, of the 

 normal amount of hemoglobin. 



