i 9 : 
HEMOGLOBIN. 
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 oxyhemoglobin, 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 methemoglobin. 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 
oxyhemoglobin. 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 oxyhemoglobin 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 hemo- 
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 oxyhemoglobin, the existence of 
at least three additional compounds of oxygen with hemoglobin, all possessing 
the spectrum of oxyhemoglobin, but differing in elementary composition and 
in their capacity to combine with oxygen), will be referred to under the heading 
of "Oxyhemoglobin." There can be no question, however, that these views 
have been completely disproved by Hiifner,- the supposed individual oxyhemo- 
globins of Bohr being mechanical mixtures of pure oxyhemoglobin 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 hemoglobin 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 — hemoglobin — 
and that in every specimen of living blood, this colouring matter exists, partly 
as oxyhemoglobin and partly as reduced hemoglobin. 
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 oxyhemoglobin 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 oxyhemoglobin and of reduced hemoglobin, 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 oxyhauno- 
"lobin, whilst that contained in venous blood should be named Phlebin, to 
1 " Ueber die Verbindungen des Hamoglobins nut Sanerstoff," " Ueber die specifisclie 
Sauerstoffmenge des Brutes und die Bedeutung deiselben fur den respiratorischen Stoff- 
wechsel," Centralbl.f. Physiol., Leipzig u. Wien, 1890, Bd. iv. S. 242, 254. 
2 In tins place it is only necessary to refer to one of Hiifiier's papers. See G. Hiifner, 
"Neue Versucbe zur Bestimmung der Sauerstofl'capacitat des Blutfarbstoffs," Arch. f. 
Physiol., Leipzig, 1894, S. 130, 176. Refer particularly to pp. 130, 134, 175, 176. 
3 Ztschr. f. physiol. Chcm., Strassburg, 1889, Bd. xiii. S. 495. 
