278 THE BLOOD. 



the formula CeseHK^sN^FeSaOisi. According to the more recent 

 determinations of HUFNER and JAQUET, ox-hsemoglobin contains an 

 average of 0.336 per cent iron, and the human haemoglobin, according 

 to BUTTERFIELD 1 contains 0.334 per cent iron. From the iron a molec- 

 ular weight of 16,669 may be calculated. BARCROFT and HILL have 

 arrived at exactly the same value by using an entirely different method 

 and HUFNER and GANSSER 2 have attempted to learn the size of the molec- 

 ular weight of haemoglobin by means of osmotic pressure determinations, 

 and they found the following approximate results: for horse-haemoglobin 

 15,115 and for ox-haemoglobin 16,321. The haemoglobin from various 

 kinds of blood not only shows a diverse constitution, but also a different 

 solubility and crystalline form, and a varying quantity of water of crys- 

 tallization; hence we infer that there are several kinds of haemoglobin. 

 BOHR is a very zealous advocate of this supposition. He has been able 

 to obtain haemoglobins from dog- and horse-blood, by fractional crystalliza- 

 tion, which had different powers of combining with oxygen and contained 

 different quantities of iron. HOPPE-SEYLER had already prepared two 

 different forms of haemoglobin crystals from horse-blood, and BOHR 

 concludes from all these observations that the ordinary haemoglobin 

 consists of a mixture of different haemoglobins. In opposition to this 

 statement, HUFNER 3 has shown that only one haemoglobin exists in ox- 

 blood, and that this is probably true for the blood of many other animals. 

 Oxyhaemoglobin, which has also been called H^EMATOGLOBULIN or 

 H^EMATOCRYSTALLIN, is a molecular combination of haemoglobin and 

 oxygen. For each molecule of haemoglobin 1 molecule of oxygen is 

 present, as shown by the investigations of HUFNER as well as HUFNER 

 and GANSSER, and the amount of loosely combined oxygen which is united 

 to 1 gram of haemoglobin (of the ox) has been determined by HUFNER 4 

 as 1.34 cc. (calculated at C. and 760 mm. mercury). 



According to BOHR, the facts are different. He differentiates between four 

 oxyhsemoglobins, according to the quantity of oxygen which they absorb, namely 



1 Hoppe-Seyler, Med. chem. Untersuch., 370; Jaquet, Zeitschr. f. physiol. Chem., 

 14, 296; Kossel, ibid,. 2, 150; Zinoffsky, ibid., 10; Hiifner, Beitr. z. Physiol., Festschr. 

 f. C. Ludwig, 1887, 74-81, Journ. f. prakt. Chem. (N. F.), 22; Otto, Zeitschr. f. physiol. 

 Chem., 7; Inoko, ibid., 18; Abderhalden and Medigreceanu, ibid., 59; Hiifner and 

 Jaquet, Arch. f. (Anat. u.) Physiol., 1894; E. Butterfield, Zeitschr. f. physiol. Chem., 

 62. 



2 Barcroft and Hill, Journ. of Physiol. 39; Hiifner and Gansser, Arch. f. (Anat. u.) 

 Physiol., 1907. 



3 Bohr, "Sur les combinaisons de 1'hernoglobine avec 1'oxygene," Extrait du 

 Bulletin de l'Acade*mie Royale Danoise des sciences, 1890; also Centralbl. f. Physiol. 

 1890, 249. Hoppe-Seyler, Zeitschr. f. physiol. Chem., 2; Hiifner, Arch. f. (Anat. u.) 

 Physiol., 1894. 



4 Arch. f. (Anat. u.) physiol., 1901, Suppl. 



