CIIKMICAL BASIS OF THK ANIMAL l',U>V. 



8. Haemochromogen. C 34 H,,N 4 FeO, (?). 



When (reduced) ha-moglobin is treated with acids, or, better 

 still, with alkalis in the entire absence of oxye.-n, it i.- d 

 posed into a proteid and a coloured sub-tan. .- t<. \\hi.-h 

 Euemochromogen P given by Hoppe-Seyler. 1 When alkalis 



an- u.-ed in its preparation, the solution obtained i> of a brilliant 

 purplish-red colour, ami is characterised by t\\<> marked al-s.-ij.- 

 tiuii band-, the stronger lying halfway between 1> ami /', the 

 other ;;ml fainter between E and I. These are identical with 

 tin- l>aiuls of Stokes' reduced luematin in alkaline solutioi 

 Fit,'- 37, No. 3). When exposed to the air (oxygen ) tin- solution 

 rapidly loses its brilliant colour, becomes dichioio, vi/. : red in 

 thick, and greenish in thin layers (cf. xnh ha-matin) and now 

 yields an absorption spectrum, which exhibits one not 

 strongly marked hand in the yellow, to the red side of It ami 

 touching the latter line. This is the spectrum of ha matin in an 

 alkaline solution (see Fig. 37, Nos. 1 and 2). "When the de. m 

 position of the haemoglobin is brought about by acids instead of 

 alkalis, the coloured product is similarly kuemochiomogeil, but in 

 this case, unless special precautions are taken, some of the ha nio- 

 chromo^en is itself further decomposed ami yields ha ma' 

 phyrin or iron-free ha-matin (see below). Tin- mixture thus 

 obtained probably accounts for the four-banded spectrum as thst 

 .lied by Hoppe-Seyler. 2 When a solution of ha-matin in 

 alkali is reduced with Stokes' fluid (see sub oxy-hu/moglohin) or 

 ainiii'inium sulphide the solution obtained shows U\ absorption 

 bands identical with those already described as chara -tei i-tie of 

 ha-nio.-hronio^en. l-'nun these fa<-t- it would at tiist si-lit . ; 

 that reduced ha-matin in alkaline solution and b.i-miK-hron 

 imilar solution are identical substances, and this is it 

 the view which has been most generally adopted. l-'mm a 

 Bpectroecopic ]>oint of view they do aj>])ear to be the same, but 

 Hoppe-Seyler maintain- that they are not. 8 According to him 

 h&mochromogeu i- a simple product of the decomposition of 

 ha-nio^lubjii, while ha-matin is an oxidi-d pioduct which dilleis 

 from true oxy-lia-mochrom-^en by he in;,' united to a smaller 

 amount of oxygen than is tin- former. lie has further 

 in obtaining imt only ha-mocln-omo^en in a crystalline form. 4 but 

 a l-o a compound of h.i-moehromo^.-n with carbon-iiHno\i,i 

 hibitinu' the al.-orption hand- of carbon-monoxide hemoglobin 

 ami containinu tlie same am.iunt of carb..n-monoxi.le unite.l to 



i M,,I.-.-I,.,H Pi* < lift M fisrii. S :.4o 'ine. 



<!, v,,l. i ], us. See A!M later Hopper vo/. Cktm. 



Hih i 



- 104, 



J. <'hrm. (1881), 8. 394. 

 9 t'. i>hv*il. i '! >. IM. MO 



4 H\ the aetfon of itraag CMMtii -!at 100 in tin- mire absence of oxrgea. 



