80 



GENERAL CHEMICAL AND PHYSICAL CHARACTERS 



Bardachzi (Zeit. f. phys. Chemie, 1906, XLIX, 465) determined the mean 

 quotient for the fresh blood of the sea-tortoise (Thalassochelys corticata) to 

 be 1.561, and for the oxyhemoglobin crystals in solution 1.569. The mean 

 quotient for methemoglobin he records as 1.184. 



The injury to the hemoglobin molecule caused by the methods of prep- 

 aration has been referred to a number of times in preceding pages. Interest- 

 ing in this connection are the results of the investigations of Kupffer (Inaug. 

 Dissert., Dorpat, 1884) and Kriiger (Zeit. f. Biologie, 1887, xxiv, 47), both 

 of whom have found that recrystallization notably and injuriously affects 

 the extinction coefficients. Kupffer determined that the oxyhemoglobin of 

 the horse and the dog showed a higher extinction coefficient when crystal- 

 lized three times than when crystallized twice; while Kriiger, using the 

 Hiifner spectrophotometer, found that even a single crystallization gives 

 rise to a higher absorption ratio. Inasmuch as this is the opposite effect 

 to that which should be expected if recrystallization means merely puri- 

 fication, it is clear that the molecule has been altered. He also calls 

 attention to the fact that the addition of ammonia increases the solubility 

 of the crystals about twice. The accompanying table (table 29) from Kruger 

 is of interest : 



TABLE 29. The effects of recrystallization and alkali upon the extinction 

 coefficient of hemoglobin, according to Kruger. 



Hoppe-Seyler in his earlier investigations (Med. chem. Untersuchungen, 

 1868, Heft 3, 366) noted that the intensity with which hemoglobin absorbs 

 the light of definite portions of the spectrum is not alike for different species. 

 Thus, to have solutions of like absorptive intensity, the following quantities 

 were necessary in a liter of solution: 1.641 grams of goose hemoglobin, 

 1.682 grams of dog hemoglobin, 1.703 grams of guinea-pig hemoglobin. 

 This has received confirmation in the researches of Abderhalden (Zeit. f. 

 physiolog. Chemie, 1898, xxiv, 545), who found that in order to obtain the 

 same colorimetric value 10 c.c. of a standard solution of dog hemoglobin 

 must bo diluted with 8 c.c. of water to have the same intensity as the same 

 standard solution of cat hemoglobin. 



THE DIFFERENCES IN THE DECOMPOSABILITY OF THE HEMOGLOBIN OF 



DIFFERENT SPECIES. 



While hemoglobin is, in comparison with proteins generally, extraor- 

 dinarily resistant to the putrefactive organisms, excepting practically in 

 so far as concerns the conversion of oxyhemoglobin into methemoglobin 

 and reduced hemoglobin, it readily undergoes decomposition, especially so 



