CHEMICAL PHYSIOLOGY. 



globin, a blue colour results. Or the reaction may be done on 

 filter paper. 



5. Spectroscopic Examination of Blood. Use a small Browning's 

 straight-vision spectroscope (Fig. 3). 



Fig. 3. Browning's Straight Vision Spectroscope. 



Preliminary. Observe the solar spectrum by placing the 

 spectroscope before the eye, and directing it to the bright day- 

 light. Note the spectrum from the red to the violet end, with 

 the intermediate colours, and particularly the dark Frauenhofer's 

 lines, known as D, E, b, and F, their position and relation to the 

 colours. Make a diagram of the colours, and the dark lines, 

 indicating the latter by their appropriate letters. 



(a.) Fix the spectroscope in a suitable holder, and direct 

 it to a gas-flame, the edge of the flame being towards the slit 

 in the spectroscope, noting that the spectrum shows no dark 

 lines. 



(b.) Fuse a piece of platinum wire in a glass tube, and 

 make a loop at the free end of the platinum wire. Dip the 

 platinum wire in water and then into common salt, and burn 

 the salt in the gas-flame, having previously directed the 

 spectroscope towards the gas-flame, and so arranged the 

 latter that it is seen edge-on. Note the position of the 

 bright yellow sodium line D. 



6. I. Spectrum of Oxy-hgemoglobin. 



(a.) Begin with a strong solution, and gradually dilute it. 

 Place some defibrinated blood in a test-tube, and observe its 

 opacity and bright scarlet colour. 



(b.) Adjust the spectroscope as follows : Light a fan-tailed 

 gas-burner, fix the spectroscope in a suitable holder, and 



