BLOOD. 



into relation with the blood specimen being examined. Trans- 

 mitted candle light is used for illumination. This instrument is 

 more accurate than the Talqvist device, but is much less convenient 

 and more expensive. 



3. Haemometer of v. Fleischl. In this instrument the 

 amount of haemoglobin in a specimen of blood is estimated by 

 comparing a stratum of diluted blood with a standard glass wedge 



FIG. 25. V. Fleischl's Haemometer (modified by Miescher). 



of uniform tint spectroscopically similar to that of the blood. This 

 instrument has been recently modified and made more accurate 

 by Miescher. 



This modification of the instrument consists of a stand with a 

 metal plate having a circular opening and a plaster mirror below 

 (see Fig. 25), which serves to reflect the light through the colored 

 wedge and diluted blood. Beneath the metal plate is a metal 

 frame carrying the colored wedge alongside of which is a scale in- 

 dicating the different percentages of haemoglobin corresponding 

 to the varying thicknesses of the wedge. This framework is 



