74 GENERAL CHEMICAL AND PHYSICAL CHARACTERS 



been shown by Wichmann (Zeit. f. physiolog. Chemie, 1899, xxvn, 575), 

 who compares protein crystals to a sponge. Moreover, in the preparation 

 of crystals of albumin, globulin, phycoerythrin, phycocyanin, hemocyanin, 

 and hemoglobin by the "salting-out" process, in the case of all excepting 

 possibly hemoglobin the crystals are not free substances, but some form 

 of combination. 



Phosphorus according to some observers is a contamination, but ac- 

 cording to others it may be or is a normal constituent. While it can be 

 removed from the hemoglobin of mammalian bloods by repeated crystal- 

 lization, this was not found possible by Hoppe-Seyler and Jacquet in the 

 case of the hemoglobins of bloods that contain nucleated erythrocytes, yet 

 Bardachzi (Zeit. f . physiolog. Chemie, 1906, XLIX, 465) has obtained from the 

 sea-tortoise crystals of hemoglobin that were free from phosphorus. The 

 fact, however, that phosphorus has been removed from mammalian hemo- 

 globins is not proof of its being a contamination, because it may have been 

 stripped from the molecule. Inoko (Zeit. f. phys. Chemie, 1894, xvm, 57) 

 regards the phosphorus as a normal constituent existing in the form of 

 nucleic acid which is in combination with hemoglobin. Jacquet (Zeit. f. 

 phys. Chemie, 1888, xn, 285) also regards it a normal constituent, but 

 Gscheidlen (Archiv f. ges. Physiologic, 1878, xvn, 421) and Gamgee (Scha- 

 fer's Text-book of Physiology, 1898, 1, 206) look upon it, doubtless correctly, 

 as a contamination. 



[Since the foregoing was put in type Abderhalden and Medigreceanu 

 (Zeit. f. physiolog. Chemie, 1909, LIX, 165) have shown, by their analyses of 

 the hemoglobin of the goose, that phosphorus is an impurity.] 



THE MOLECULAR FORMULA AND WEIGHT OF HEMOGLOBIN. 



The molecular formulas and molecular weights of proteins, especially 

 of the coagulable proteins, are admittedly high, and are particularly high in 

 the chromoproteins. Owing, however, to the difficulty of obtaining these 

 substances of uniform purity, the estimates must be regarded as being 

 purely tentative. Vaubel (Jour. f. prakt. Chemie, 1899, LX, 55) gives the 

 following figures which he compiled from the records of different investi- 

 gators, which records were obtained by various methods of determination: 

 Egg albumin 4618 to 6542; serum albumin 4572 to 5135; myoalbumin 4572 

 to 5135; casein 6500 to 6542; plant albumin 5050 to 6690; plant globulins 

 5257 to 8848; globin 15000 to 16086; and hemoglobin 15000 to 16730. 



Inasmuch as we have not a rational formula for hemoglobin, the 

 empirical formulas and weights must be regarded sub judice. The calcu- 

 lation of the molecular formula of the hemoglobin of the horse by Schulz 

 was based upon the sulphur content (table 27). Preyer (Die Blutkrystalle, 

 1871, 65), Hiifner (Jour. f. prakt. Chemie, 1880, xxn, 362; Zeit. f. physiol. 

 Chemie, 1884, vm, 361), Zinoffsky (Zeit. f. physiol. Chemie, 1885, x, 16), and 

 Jacquet (Zeit. f. physiol. Chemie, 1889, xiv, 289) made determinations 

 based upon the percentages of Fe; and Hiifner verified Jacquet's figures 

 for the hemoglobin of the dog by determinations of the combining proper- 

 ties of hemoglobin with O and CO. Hufner and Ganser (Archiv f. Anat. u. 



