PHYSIOLOGICAL PHYSICS. [Chap. xxvi. 



been used. Each condition has a spectrum of its 

 own. Tlie ACID H^MATIN (Stokes) gives one absorp- 

 tion band in the red in close proximity to the dark 

 band c of the solar spectrum. The spectrum of 

 ALKALI H^EMATIN consists of one dark band to the red 

 side of the D line. 



REDUCED H^MATHST gives two faint bands, one 

 broad, and immediately to the violet side of D, the 

 other narrower, and a little to the red side of the E 

 line, the violet end of the spectrum being less ab- 

 sorbed than with unreduced hsematin. 



Fig. 151. Blood Spectra. 



Fig. 151 shows several of these characters, i being 

 the spectrum of oxyhsemoglobin, n of reduced hsema- 

 globin, v of reduced hsematin, vi and vn of hsematin 

 in alkaline and acid solutions, in and iv of methse- 

 moglobin in alkaline and acid solutions respectively. 

 Methsemoglobin is obtained by exposure of a solu- 

 tion of hsemaglobin for a long time to the air, or by 

 the use of oxydising agents. The letters mark the 



