202 H.EMOGLOBIX. 
the discrepancies between the results of the ultimate organic analyses 
yet made, the oxyhemoglobin possesses the same molecular weight. 
The concordance between the more recent determinations of the iron 
of oxyhemoglobin is well shown in the table given on the previous 
page. 
On the assumption that one molecule of haemoglobin contains one 
atom of iron, the molecular weight of the haemoglobin of the doe - , horse, 
ox, and hen would be 16,669, and this result is borne out, as will be 
afterwards shown, by the volume of oxygen or of carbonic oxide which 
enters into combination with the blood-colouring matter. 
In addition to the estimation of the iron in haemoglobin, that of 
the sulphur has been carried out with remarkable care by Hiifner, 1 
Zinoffsky, and Jaquet ; and their results, whilst establishing that the 
centesimal composition of the blood-colouring matter of all animals is 
not identical, show that in haemoglobin the sulphur stands to the iron 
in definite relations. 
Thus Zinoffsky 's analyses appear to establish that in the haemoglobin 
of the horse the sulphur is to the iron in the relation of two atoms of 
the former to one of the latter element, ami Hiifner has shown that 
exactly the same relation obtains in the case of the haemoglobin of the 
ox and the pig. On the other hand, Jaquet's analyses of the haemo- 
globin of the dog indicate that in it three atoms of sulphur correspond 
to one atom of iron. When, in a subsequent section, we shall examine 
the products of decomposition of haemoglobin, we shall show that, under 
the influence of acids and alkalies, the blood-colouring matter breaks 
up into an iron-containing body (of which the composition and the 
properties vary according to the presence or absence of oxygen during 
the decomposition) and into an albuminous body or bodies. The 
sulphur of haemoglobin belongs to the albuminous part of the molecule, 
and the difference in the relation of S to Fe, brought out by the 
researches of Hiifner, Zinoffsky, and Jaquet indicates that the albuminous 
moiety of the haemoglobin molecule varies in different animals, and that 
among the points of difference is the difference in the proportion of 
sulphur. Tins point will be certainly cleared up by future researches 
specially directed to its elucidation; it may be remarked, however, 
that the proportion of sulphur in different albuminous bodies does 
exhibit great variations. 
It appears to me, moreover, that we must not lose sight of the possi- 
bility (even when there is no evidence afforded by ultimate organic 
analysis of there being a difference in the percentage composition of the 
albuminous part of the haemoglobin moiety), and indeed probability, that 
haemoglobins varying in certain physical properties may be formed by tTie 
linking of the iron-containing molecule to various polymeric combinations of 
tin- same albuminous molecule. 
Although it is highly probable that the molecular weight of the 
haemoglobin of the dog and of the ox (16,669), as determined by the 
iron determinations of Jaquet and Hiifner, and by determinations by 
Hiifner of the volumes of and CO with which haemoglobin combines, 
has been ascertained with correctness, or nearly so, the discrepancies in 
the results of the determinations of C, H, and 1ST, made by different 
observers, are too great to warrant our placing confidence in the 
empirical formulae which have been assigned to haemoglobin. Of these 
1 " Bestimmung d. Sauerstoffscapacitat d. Blutfarbstoffs." S. 76. 
