168 THE AMERICAN MONTHLY [May 



and a capillary pipette for measuring the blood. The 

 blood obtained, by puncturing the finger, is drawn by 

 capillarity into the pipette, from which it is washed into 

 one of the chambers of the well. 



Here it is thoroughly mixed with the water. Both 

 compartments are then filled with water and the well is 

 covered by a glass plate. The well is placed upon the 

 stand so that the compartment filled with distilled water 

 is over the colored wedge. This is moved by a screw 

 until its color corresponds to that of the diluted blood in 

 the other compartment. The percentage of haemoglobin 

 is then read oif from the attached scale. In using the 

 Fleischl, artificial light is necessary, daylight being ex- 

 cluded. 



The hferaoglobinometer of Gowers is usually manufac- 

 tured with but one colored tube, which is for use with 

 daylight. There is another form in which there are two 

 tubes, one for use with daylight and the other for artificial 

 light. The one which we have used is of the former kind. 

 It consists of a sealed tube filled with a glycerine-jelly 

 solution of carmine and picro-carmine of the color 

 of a one-per-cent solution of normal blood; another 

 tube of the same diameter to hold the blood to be 

 tested ; a pipette graduated to 20 cu. mm. and a stand 

 to hold the two tubes, side by side. The blood measured 

 in the pipette is mixed with a small quantity of water in 

 the graduated tube ; water is then added until the dilution 

 corresponds in color to that of the standard solution in 

 the other tube. In making the comparison it is neces- 

 sary to hold the instrument against a white back ground, 

 opposite the source of light or directly between the eye 

 and the window. 



The method which we have used for determining the 

 specific gravity, and thus the hfemoglobin of the blood, 

 is not so well known as the above and will therefore 

 bear a more detailed description. It is one used by 



