192 HAEMOGLOBIN. 



The extraordinary difference in the result predisposes one at first to 

 conclude that it must be due to a radical difference betwen the colouring 

 matter of the corpuscles and oxyhaemoglobin, such as Hoppe-Seyler believed to 

 exist. If, however, instead of the solutions mentioned above, solutions ten 

 times more dilute (containing 0*25, 0*5 and 1 per cent.) be mixed with 

 defibrinated blood in the same proportions as before, the mixture assumes 

 instantly the colour, and exhibits the spectrum of methsemoglobin. In this 

 case the dilute solution extracts, in the first instance, the blood-colouring 

 matter from the corpuscle, and then the ferricyanide acts upon the solution, 

 exactly as it does when brought in contact with a solution of crystals of 

 oxyhaernoglobin. The fact that the strong solution of potassium ferricyanide 

 does not act upon the colouring matter of the blood corpuscles, is due to its 

 incapacity to reach, in the first instance, the oxyhaemoglobin of the corpuscles. 

 In this case also, it appears that the difference (supposed) between the colour- 

 ing matter, as it exists in the intact blood corpuscles and solutions of haemo- 

 globin, is only an apparent one. 



Though closely connected with the subject which has been discussed in 

 this section, the views of Bohr 1 (who believes that he has succeeded in 

 establishing, in addition to the already known oxyhaemoglobin, the existence of 

 at least three additional compounds of oxygen with haemoglobin, all possessing 

 the spectrum of oxyhaemoglobin, but differing in elementary composition and 

 in their capacity to combine with oxygen), will be referred to under the heading 

 of "Oxyhaemoglobin." There can be no question, however, that these views 

 have been completely disproved by Hiifner, 2 the supposed individual oxyhaemo- 

 globins of Bohr being mechanical mixtures of pure oxyhaemoglobin with 

 products of its decomposition, the necessary results of the methods of pre- 

 paration followed by the Scandinavian observer. 



We have shown that even admitting, for the sake of argument, the 

 correctness of all Hoppe-Seyler's statements, these when carefully analysed 

 afford no evidence whatever in support of his bold hypothesis. Whilst such 

 is the case, the splendid investigations of Hiifner 2 have conclusively proved 

 that, in respect of its power of combining with oxygen, the blood-colouring 

 matter, as it exists in the coloured blood corpuscles, behaves precisely as a 

 solution of pure haemoglobin of the same concentration. Further, by the 

 method of spectrophotometry, Hiifner has shown, as could be done by no 

 other method, that the colouring matter of the blood is one haemoglobin 

 and that in every specimen of living blood, this colouring matter exists, partly 

 as oxyhaemoglobin and partly as reduced haemoglobin. 



The discussion which has preceded will have prepared the reader for the 

 conclusion, which appears to be the only one which can legitimately be based 

 upon the facts in our possession to wit, that whilst oxyhaemoglobin and 

 reduced haemoglobin exist in the coloured blood corpuscles in the form of 

 loose or unstable combinations with some other constituent of the corpuscle, 

 evidence is altogether wanting in support of Hoppe-Seyler's contention that 

 the blood- colouring matter, as it exists in the corpuscles, possesses properties 

 so different from those of oxyhaemoglobin and of reduced haemoglobin, as to 

 warrant its being looked upon as a distinct substance, to be distinguished by 

 a different name. Hoppe-Seyler suggested, 3 indeed, that the colouring matter 

 of arterial blood should be called Arterin, to distinguish it from oxyhaemo- 

 globin, whilst that contained in venous blood should be named PMebin, to 



1 " Ueber die Verbindungen des Hamoglobins mit Sauerstoff," " Ueber die specifische 

 Sauerstoffmenge des Blutes und die Bedeutimg derselbeii fur den respiratorischen Stoff- 

 wechsel," Centralbl.f. PhysioL, Leipzig u. Wien, 1890, Bd. iv. S. 242, 254. 



2 In this place it is only necessary to refer to one of Hiifner's papers. See G. Hiifner, 

 "Neue Versuche zur Bestimrnung der Sauerstoff capacitat des Blutfarbstoffs, " Arch. f. 

 PhysioL, Leipzig, 1894, S. 130, 176. Refer particularly to pp. 130, 134, 175, 176. 



3 Ztschr. f. physlol. Chem., Strassburg, 1889, Bd. xiii. S. 495. 



