GENERAL PROPERTIES! THE CORPUSCLES. 



433 



used (see Fig. 184) or, if the concentration remains the same, 

 with the width of the stratum of liquid through which the light 

 passes. With a certain minimal percentage of oxy hemoglobin 

 (less than 0.01 per cent.) the /5-band is lost and the a-band is very 

 faint in layers 1 centimeter thick. With stronger solutions the 

 bands become darker and wider and finally fuse, while some of the 

 extreme red end and a great deal of the violet end of the spectrum 

 are also absorbed. The variations in the absorption spectrum, 

 with differences in concentration, are clearly shown in the accom- 

 panying illustration from Rollett * (Fig. 184) ; the thickness of the 

 layer of liquid is supposed to be one centimeter. The numbers 

 on the right indicate the percentage strength of the oxyhemoglobin 

 solutions. It will be noticed that the absorption which takes 



L..I,...L.bJl.,fl U .,lmli.J Ll,,ll LllniL.lllll LlllU Hill 



Fig. 183. Table of absorption spectra (Ziemke and Muller) : 1, Absorption spectrum 

 of oxyhemoglobin, dilute solution; 2, absorption spectrum of reduced hemoglobin ; 3, ab- 

 sorption spectrum of methemoglobin, neutral solution; 4, absorption spectrum of met- 

 hemoglobin, alkaline solution ; 5, absorption spectrum of hematin, acid solution ; 6, ab- 

 sorption spectrum of hematin, alkaline solution. 



place as the concentration of the solution increases affects the 

 red-orange end of the spectrum last of all. 



* Hermann's "Handbuch der Physiologie," vol. iv., 1880. 



28 



