VII.] 



WAVE-LENGTHS. 



55 



ha'.matin precipitate. Dissolve the hnematin in water containing a trace of 

 HC1. It will give the spectrum of acid hnematin. To one portion add some 

 of the decanted fluid and a few drops Am 2 S, to.another add Am 2 S only. In 

 the former case the haemochromogen formed will gradually become partially 

 converted into Hb (prove by shaking with air and obtaining spectrum of 

 Hb0. 2 ), in the latter case the hsemochromogen will remain unaltered. 



LESSON VII. 



WAVE-LENGTHS DERIVATIVES OF HAEMO- 

 GLOBINESTIMATION OP HAEMOGLOBIN. 



Spectroscopic Determination of Wave-Lengths. Use Zeiss's 

 spectroscope, which is provided with an illuminated scale for this 

 purpose. 



1. W.L. of Absorption-Bands of Oxy-Haemoglobin. 



(a.) Arrange the apparatus as shown in fig. 31. A is the 



FIG. 31. Arrangement of the Spectroscope for Determining Wave-Lengths. A. Tele- 

 scope; B. Collimntor tube ; C. Scale tube ; D. Hsematinometer. 



telescope through which the observer looks at the spectrum 

 obtained by the light passing th rough P>, and dispersed by the 



