THE RED BLOOD CORPUSCLES 



191 



colometric substitute; for example, solutions of the more stable compounds of 

 hemoglobin, solutions of picrocarmin and colored glass. 



The instruments which have been devised to permit of a comparison of this 

 kind are called hemoglobinometers, or hemo- , 

 meters. Hoppe-Seyler employed two glass 

 troughs with parallel sides, into one of 

 which he placed a standard solution of oxy- 

 hemoglobin of known strength, and in the 

 other, the blood to be tested. The pro- 

 cedure consisted in diluting the sample of 

 blood until its color corresponded precisely 

 with that of the standard solution. The 

 quantity of water necessary to attain this 

 end, enables one to calculate the propor- 

 tion of hemoglobin in the undiluted blood. 

 The procedure advocated by Tallqvist,^ 

 consists in permitting a drop of blood to 

 fall upon white filter paper. When evenly 

 diffused the color of the stain is compared 

 with similar permanent stains indicating 

 the different percentages of hemoglobin 

 from 10 to 100. The hemophotographic 

 method of Gartner^ is based upon the fact 

 that a solution of oxyhemoglobin absorbs 

 the rays of light in a steadily increasing 

 measure with its concentration. Fleischl's 



instrument^ consists of a short cylindrical receptacle which is divided into two com- 

 partments by a vertical median partition. Into one of these is placed a measured 



Fig. 105. — Hemoglobinometer. 



(Fleischl's.) 



S, stage; R, reflecting mirror; B, 

 screw for adjusting position of colori- 

 metric wedge; A, the cylindrical re- 

 ceptacle. C, contains two compart- 

 ments into one of which is placed 

 the sample of blood to be examined. 



r\/7 



100 



io 



C 



iOimn* 



B 



D 



Fig. 106. — Hemoglobinometer. (Gowers.) 

 A, tube filled with colored fluid; B, tube for mixing blood; C, receptacle for distilled 

 water with dropper; D, pipet. 



^ Berliner klin. Wochenschr., 1904. 

 2 Miinchener med. Wochenschr., 1901. 



^Wiener med. Jahresb., 1885; modified by Miescher, Korresp. f. Schweizer 

 Arzte, xxiii, 1893. 



