78 GENERAL CHEMICAL AND PHYSICAL CHARACTERS 



1.357, and for the rat 1.337. He also found the like value in the case of man, 

 the cat, and the owl. 



Otto (Zeit. f. physiolog. Chemie, 1882, vn, 57) noted with solutions of 

 the oxyhemoglobin of the dog and pig a quotient of 1.33; and in a later 

 research, with an improved form of spectrophotometer, obtained a quotient 

 of 1.352 for horse oxyhemoglobin and 1.34 for that of the dog. Sczelkow 

 (Archiv f. ges. Physiologic, 1887, XLI, 373) calculated, by means of Hiifner's 

 spectrophotometer, a quotient of 1.336 for horse hemoglobin. For dog's 

 hemoglobin he recorded 1.305, which he looks upon as not being correct, 

 and he remarks that coefficients obtained by him differed from each other 

 and from the mean value much more than did Otto's, which differences he 

 explains upon the assumption that the concentration of the solutions used 

 by him differed more than those employed by Otto. 



Hiifner, in the more recent investigation referred to, found these quo- 

 tients so constant and specific that he formulated tables by aid of which the 

 quantity of oxyhemoglobin, reduced hemoglobin, methemoglobin, or CO- 

 hemoglobin, or the quantities in mixtures of oxyhemoglobin and reduced 

 hemoglobin, or of methemoglobin and CO-hemoglobin may be determined. 

 Moreover, he states that these quotients, as well as the O, CO, and the iron 

 capacities of the coloring matter of the blood, are not only the same in 

 related but also in unrelated species, and that when this coloring matter is 

 freed from water it has in all of the higher animals the same molecular 

 weight and the same capacity for O and CO. 



In opposition to Hiifner's assertion of the constancy of the extinction 

 coefficients and quotients of the same and of different bloods, we find 

 evidence in the results of a number of investigations. The quotients given 

 by von Noorden, Otto, and Sczelkow already noted are far off. Korniloff 

 (Zeit. f. Biologic, 1876, xu, 513) determined the extinction coefficients 

 in relation to the second absorption band (B) of the coloring matter of the 

 blood of 110 vertebrates, comprising 44 species. He made determinations 

 by other regions of the spectrum, but these values deviated considerably 

 from those obtained from the second band. Inasmuch as he did not make 

 his determinations by the effects on two bands, which is necessary to obtain 

 accurate results, and as the bloods doubtless contained variable proportions 

 of oxyhemoglobin and reduced hemoglobin, and in some instances probably 

 methemoglobin if not also other coloring matters, his figures must be looked 

 upon as representing only approximate values. Accepting them as approx- 

 imations, they differ so much as to indicate that the coefficients in at least 

 different orders of animals are very far from being identical, as will be 

 seen by the figures in table 28. 



Kruger (Zeit. f. phys. Chemie, 1898, xxv, 256) found the quotient of 

 cat's oxyhemoglobin to be 0.128, and for that of the dog 0.137. Velichi 

 (Inaug. Dissert. Berlin, 1900; Centralbl. f. Physiologie, 1900, xiv, 679; 

 Dcutsch. med. Wochenschr., 1900, xxvi, 148) found such differences in the 

 extinction coefficients that he states that the hemoglobins of all classes of 

 animals are not identical. Dreser (loc. cit.) gives 1.557 as the quotient for 

 human oxyhemoglobin, and Saint Martin (Compt. rend. soc. biologic, 1901, 

 LIII, 302) obtained the following quotients: Human 1.60, bullock 1.62, dog 



