BLOOD. 



81 



dilution tile latter is seen to consist of two absorption 

 bands, one, situated towards the red, close upon the 

 D line, is narrower, darker, and better defined, while 



AaBC D 



HH' 



Spectrum of Blood. 



the second one situated towards the green on the 

 side of the E line, which is towards D, is wider and 

 paler. Dilute the solution gradually and observe how 

 the bands become paler. Study these phenomena 

 upon all kinds of red blood and red muscular tissue. 



7. Treat a solution of blood which exhibits the two 

 absorption bands with hydrogen or arseniuretted 

 hydrogen gas, or with a solution of ferrous sulphate 

 containing tartaric acid and excess of ammonia, the 

 air being in each case excluded from contact with the 

 mixture, and observe that the colour of the solution 

 alters to purple^ and that before the spectroscope only 

 one broad band is seen in the place of the former two. 



AaBC D 



Eb 



HH' 



Spectrum of reduced Hematocrystalline. 



8. Shake up the solution prepared according to the 



6 



