COMPOUNDS OF HEMOGLOBIN. 



(Fraunhofer's lines) which occupy definite positions in the coloured spectrum. These lines are 

 indicated by the letters A, B, C, D, &c, a, b, c, &c. (fig. 17). 



15 COMPOUNDS OF HB WITH ; OXYHEMOGLOBIN AND METHE- 

 MOGLOBIN. 1. Oxyhemoglobin (0.,Hb) behaves as a weak acid, and occurs to 

 the extent of 86*78 to 94 30 per cent, in dry human red corpuscles (Judell). It is 

 formed very readily whenever Hb comes into contact with O or atmospheric air. 

 According to Bohr, 1 gramme Hb unites with 1 -56 cubic centimetre of O at and 

 760 mm. Hg pressure, the union being stronger in weak than in concentrated 

 solutions. OxyhaMnoglobin is a very loose chemical compound, and is slightly 

 less soluble than Hb ; its spectrum shows in the yellow and the green two dark 



Bed. Orange. Yellow. 



Cyan blue. 



A a B C D 



4o 60 bo 7o 



,M l,M.1....l...|l ,.,.I..LlWklll] 



Oxy.= 



Iliimoglobin 



0-8% 



Oxy.= 



lliimoRlobin 



0-18 % , 



Carbonic 



Oxide 



Hiimogiobin. 



6b 



D E F 



Fig. 17. 



Spectra of hemoglobin and its compounds. 



absorption-bands, whose length and breadth in a 0*18 per cent, solution are given 

 in fig. 17 (2). - 



It occurs in the blood-corpuscles circulating in arteries and capillaries, as can be 

 shown by the spectroscopic examination of the ear of a rabbit, of the prepuce, and 

 the web of the fingers (Vierorrft). 



[Spectrum of Oxyhemoglobin. In the spectrum of a dilute solution of haemo- 

 globin crystals or arterial blood, part of the red and violet rays are absorbed, 



