BLOOD. 79 



broader, and more sharply defined. This spectrum is very 

 characteristic. 



(/) Carbon Monoxide Hcemoglobin. Carbon monoxide 

 haemoglobin may be easily prepared by passing ordinary coal- 

 gas through defibrinated blood until the latter assumes a 

 carmine or cherry-red color characteristic of the combination 

 of CO with haemoglobin. Examined spectroscopically such a 

 solution shows two bands similar to oxyhaemoglobin except 

 that the bands of the C0-ha3moglobin spectrum are nearer to 

 the violet end. Add Stokes' reagent to the solution; the 

 spectrum remains unchanged. 



Make the following tests, first with diluted blood (oxy- 

 haemoglobin) and then with diluted CO-hsemoglobin; note the 

 differences carefully: 



(a) Add to 5 c.c. of the blood 3 c.c. (NH 4 ) 2 S. 



(6) 5 10 c.c. of Stokes' reagent. 



(c) Shake with air. 



What is characteristic and important in the combination of 

 CO with haemoglobin as shown by the above experiments? 

 Make drawings of all the spectra seen and compare them with. 

 those in the text-books. 



