278 



THE BLOOD. 



of which corresponds to a known percentage of hemoglobin. 

 The one that corresponds to the color of the sample of blood 

 determines the percentage of hemoglobin in the blood under ex- 

 amination. 



Gowers' Hemoglobinometer (Fig. 148). This apparatus consists 

 of two glass tubes having the same diameter, d contains glycerin- 

 jelly colored with carmine, so that the color represents that of 

 blood diluted one hundred times with water. The finger is pricked 

 with the needle/, and the blood is sucked up into the pipet b to 

 the 20 cu.mm. mark, and then blown out into the tube c ? distilled 

 water being added in drops from a until the color of the diluted 

 blood corresponds with the color in d. The tube c is so graduated 

 that when filled to 100 with diluted blood its color corresponds to 



FIG. 148. Gowers' hemoglobinometer : a, pipet bottle for distilled water; 6, 

 capillary pipet ; c, graduated tube ; d, tube with standard dilution ; /, lancet for 

 pricking the finger. 



that of d, which would consequently represent the color of normal 

 blood. If, therefore, in order to produce a color corresponding to 

 that in d, water must be added to fill the tube to a higher level 

 than 100, the hemoglobin is above normal; while if, on the other 

 hand, the color is produced below 100, then the graduation at 

 that point represents the percentage of the normal. Thus if at 

 75 the corresponding color is reached, only 75 per cent, of the 

 normal amount is present. 



Von FleiscMs Hemometer (Fig. 149). This consists of a stand 

 carrying a white reflecting surface, e, and having a platform below 

 upon which slides a glass wedge colored red, b. On the platform 

 is a compartment, d, divided into two by a vertical partition. The 

 one which is directly above the colored wedge is filled with distilled 

 water. Into the other, a small amount of distilled water is placed. 



