70 GENERAL CHEMICAL AND PHYSICAL CHARACTERS 



(2) A portion of the electrolytes and of the hemoglobin is in solution 

 as such, and the rest exists in a solid or semisolid form united to some 

 constituent of the stroma. 



(3) A portion of the electrolytes, but none of the hemoglobin, is in solu- 

 tion as such; the whole of the hemoglobin and the rest of the electrolytes 

 being in solution in the form of such compounds as are mentioned in (1). 



(4) A portion of the electrolytes, but none of the hemoglobin, is in 

 solution as such; the rest of the electrolytes and all of the hemoglobin are 

 united in the stroma. 



The last hypothesis, he thinks, best takes account of the facts of laking. 



Oxygen, it seems, serves as a connecting link not only between globin 

 and hematin, but also between the stroma and hemoglobin. The removal 

 of oxygen from the blood causes hemolysis. This phenomenon might, at 

 first thought, be regarded as a mechanical effect due to the rapid dis- 

 charge of from the erythrocytes when the blood is subjected to the vac- 

 uum pump, but this is negatived by the fact that hemolysis occurs just the 

 same when a continuous stream of CO 2 is passed through the blood and 

 the O thus driven off gradually. Even the linkage between globin and 

 hematin may be broken by C0 2 . 



That the hypothetical union between hemoglobin and the stroma 

 must be a feeble one is evident in the readiness with which it is broken, 

 by the removal of O from the blood, by minute quantities of foreign serum, 

 snake venom, and certain bacterial products, by repeated freezing and 

 thawing, etc. While it thus seems probable that the hemoglobin of the 

 corpuscles is essentially or solely in some form or forms of union with the 

 stroma, it is also probable, from the investigations of Hiifner (Archiv f. 

 Anat. u. Physiologie, 1894, 135, 176), that the combination does not, in 

 opposition to Hoppe-Seyler's statements, effect a marked alteration in the 

 chemical nature of hemoglobin in so far as pertains to its relations to oxygen 

 and to light, for he found that its behavior to oxygen and its spectropho- 

 tometric properties are the same as when the hemoglobin is free, provided 

 the solution be of the same degree of concentration. On the other hand, 

 it is positive that at least the degree of solubility in relation to the plasma 

 and the crystallizability are lessened to a marked degree, so much so that 

 the crystallization may occur in the plasma of partially laked blood and 

 not in the corpuscles, even though in the latter the concentration of the 

 hemoglobin may be greatly higher. The corpuscles of the dog contain about 

 33 per cent of hemoglobin, while the highest percentage that could exist 

 in the laked blood is about half of this; but while crystallization does not 

 occur in the corpuscles, it does occur rapidly in the laked blood. (See 

 Chapters V and XV.) 



THE ELEMENTARY COMPOSITION OF HEMOGLOBIN. 



The determinations of the centesimal composition of hemoglobin of 

 different species of animals differ sufficiently to indicate that all hemoglobins 

 are not alike ; but these differences are not on the whole greater than those 

 noted in the analyses of specimens of blood from individuals of the same 



