The Reaction between Oxygen and Hemoglobin. 77 



range of concentration (2-fold) the CO absorption pro gram hemo- 

 globin is practically constant for laked ox blood or human blood. 

 (In the table, c = hemoglobin concentration, gram in 100 c.c, CO = 

 volume CO absorbed by hemoglobin, Hb. = total hemoglobin 

 quantity in grams, and p = pressure of CO in mm.) The devia- 

 tions are no greater than could be accounted for by the slight 

 decrease of the solubility of CO in hemoglobin solutions of ascend- 

 ing concentrations. It will be noticed that at a CO pressure of 

 650 mm. the limit I mol. CO to I mol. hemoglobin is almost 

 reached (theor. 1.34 c.c. CO pro gram hemoglobin). The differ- 

 ence again is in all probability due to the difference in coefficients 

 of absorption of CO in H 2 0 and in blood of the concentrations 

 studied. The reason for the good agreement between the values 

 for ox blood and human blood rests in the identity of the optical 

 constants for human hemoglobin and ox hemoglobin. 



The second series of results was obtained by the method of 

 Paal. Reduction of dialyzed solution of oxyhemoglobin, saturated 

 with air at the prevailing atmospheric pressure, in an atmosphere 

 of hydrogen in the presence of colloidal palladium. The quantity of 

 hydrogen absorbed was measured. It was assumed that under the 

 conditions of the experiment oxyhemoglobin + H 2 = H 2 0 + hemo- 

 globin. Previously the quantity of H 2 absorbed by 0.1 gram Pd 

 in no c.c. H 2 0 was determined. This was deducted from the 

 total H 2 absorbed in the experiments with hemoglobin. In all 

 of these experiments 0.1 gram Pd and no c.c. solution were 

 constantly used. Hemoglobin concentration determined gravi- 

 metrically. It will be seen from the table that for an almost 10- 

 fold variation in the hemoglobin concentration the quantity of 

 0 2 pro gram Hb. remains constant. The value is considerably 

 lower than for CO at high pressures. It is not necessary to go 

 into the various possibilities (incomplete reaction, adsorption of 

 hemoglobin by Pd, etc.) which may account for this difference. 

 It suffices here to call attention to the fact that the quantity of 

 0 2 given off pro gram Hb. to a reducing agent is independent of 

 the total hemoglobin concentration if the solutions have been 

 previously saturated at the same partial pressure of oxygen. 



The third series 1 was obtained by the ferricyanide method of 



1 From an unpublished study on the action of pneumococcus on blood, by Dr. 

 F. W. Peabody and myself. 



