118 



ESSENTIALS OF CHEMICAL PHYSIOLOGY 



thick band overlapping both D and E, and a stronger solution only 

 lets the red light through between C and D. A solution which gives 



Fin. 35. Stand for direct-vision spectroscope : S, spectroscope : T, test-tube for coloured 

 substance under investigation. 



the two characteristic bands must therefore be a very dilute one. 

 The one band (y band) of haemoglobin (fig. 37, spectrum 3) is not so 



ABO 



Pro. 36. Graphic representations of the amount of absorption of light by solution (I) of oxyhaemo- 

 globin, (IT) of hemoglobin, of different striMiL'tlis. The shading indicates the amount of 

 absorption of the spectrum ; the figures on the right border express percentages. (Rollett.) 



well defined as the a and ft bands. On dilution it fades rapidly, so 

 that in a solution of such strength that both bands of oxyhaemoglobin 



