106 COMPOUNDS OF HAEMOGLOBIN WITH CO AND NO. [BOOK I. 



of oxy-haemoglobin a corresponds to W. L. 5830, of (3 to 5450 ; of 

 CO-Hb a corresponds to W. L. 5755 and ft to 5420. 



From our own observations we conclude in the case of the band a of oxy- 

 haemoglobin that its centre certainly corresponds almost exactly with W. L. 

 5780 (expressed in 10 millionths of a mm. for comparison with Jaderholm). 

 The band a of CO-haemoglobin corresponds, on the other hand, approxi- 

 mately to wave-length 5720. The centre of CO-haemoglobin (3 is from 5340 

 to 5380 according to concentration. It will be seen that these determi- 

 nations differ very materially from those of Jaderholm and Sorby. 



It has been shewn by the researches of the Author 1 , of Bonders 2 , 

 and of Zuntz 3 , that although the compound of CO and haemoglobin is 

 much more stable than that of 0, it yet can be decomposed, and CO 

 expelled. By passing a neutral gas, or air, through solutions of 

 CO-haemoglobin for long periods the gas may be gradually driven 

 out, and the haemoglobin again becomes reducible. The same 

 happens if the blood be boiled in the mercurial pump. 



The great stability of CO-haemoglobin enables us to detect it in the 

 blood of animals poisoned by this gas or by gaseous mixtures which 

 contain it. 



The blood in these cases presents sometimes an unusually and per- 

 sistently florid colour ; whether it does so or not, it however is in great 

 part irreducible, i.e. after acting upon it with reducing agents two bands 

 yet remain in its spectrum. 



It has recently been shewn by Hoppe-Seyler 4 that the CO-haemoglobin 

 resists putrefaction for very long periods of time, so that two bands 

 remain visible for months and even years, whilst when normal blood 

 putrefies, the reduction of its O 2 -Hb to Hb takes place at once. 

 According to Hoppe-Seyler the fact that long-kept blood exhibits two 

 bands is a proof by itself that its haemoglobin has been combined 

 with CO. 



In a later section of this chapter it will be mentioned that a useful test 

 for CO-blood is the production of a cinnabar-red precipitate on the 

 addition of caustic soda; this is believed by Jaderholm 5 to be due to the 

 formation of a compound of CO with haematin. 



Nitric So great is the affinity of this gas for oxygen 



oxide, NO. ^ nat ^ momen t ft comes in contact with it, deep red 



fumes of nitrogen peroxide, N0 2 , are formed, and when these meet 



water the decomposition indicated in the following equation results : 



3N0 2 + H 2 = 2HNO 3 + NO. 



. As has been previously said, all free acids, and salts with acid 

 reaction, ipso facto decompose the colouring matter of the blood, and 



1 Gamgee, Journal of Anatomy and Physiology, vol. i. (1867) p. 346. 



2 Donders, "Der Chemismus der Athmung, ein Dissociations-Process." Pfliiger's 

 Archiv, v. 2026. 



3 Zuntz, "1st Kohlenoxydhaemoglobin eine feste Verbindung? " Pfluger's Archiv, 

 v. 584588. 



4 Hoppe-Seyler, " Unveranderlichkeit des Kohlenoxyd-Hamoglobin bei Einwirkung 

 von Faulniss oder Pankreasferment ; Werth dieses Verhaltens fur den Nachweis der 

 Kohlenoxydvergiftung." Zeitschriftf.phys. Chem., Vol. n. p. 131. 



5 Jaderholm, loc. cit. 



