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TEXT-BOOK OF PHYSIOLOGY. 



Cowers' hemoglobinometer consists of two glass tubes of exactly the 

 same size and similar to those shown in Fig. 106. One y A, contains glycerin 

 jelly colored with picro-carmine the shade of which corresponds to that of 

 normal blood diluted 100 times (20 c.mm. in 2000 c.mm. of water), repre- 

 senting a i per cent, solution. The other tube, B, is ascendingly graduated 

 with 120 divisions, each one of which corresponds to 20 c.mm. With a 

 graduated pipette, D, 20 cubic millimeters of blood are accurately measured 

 and dropped into the bottom of the tube B, in which a few drops of distilled 

 water have been placed so as to prevent coagulation. Water is then added 

 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 

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

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



FIG. 106. HALDANE'S MODIFICATION OF GOWERS' APPARATUS. 



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. 



Haldane's Modification of Gowers* Method. Haldane's hemoglobin- 

 ometer, Fig. 106, is a modification of that of Gowers. The tube A contains 

 also a i per cent, solution of blood having the normal percentage of hemo- 

 globin saturated with carbon monoxid. With the graduated capillary 

 pipette, D, 20 cubic millimeters of blood are then obtained from a slight 

 wound in the ringer or elsewhere and then dropped into the tube B, in which 

 a small quantity of distilled water from E was previously placed to prevent 

 coagulation. The cap of G is then attached to a gas burner, through which 

 flows either pure CO or a gas containing CO and the rubber tube inserted 

 into D to the level of the water. After the gas has been flowing for a few 



