COMPOSITION OF THE BLOOD-PLASMA. 17 



constituent of the corpuscles by adding to defibrinated blood about one-half iis 

 volume of a solution of sodium chloride containing one part in ten of water. 

 Allowing this to stand for ten to fifteen hours, there appears a viscid mass, 

 which is very carefully washed with water until all the coloring matter 

 and the salt added have been removed. The whitish, translucid mass which 

 remains is called globuline. Globuline is readily extracted from the blood of 

 birds but is obtained with difficulty from the blood of the human subject. 



Hcemaglobine. This is the coloring matter of the red corpuscles. It has 

 been called by different writers, haemaglobuline or haematocrystalline ; but 

 the crystals called haematine and haematosine are derivatives of haemaglobine 

 and are not normal constituents of the blood. Haemaglobine may be ex- 

 tracted from the red corpuscles by adding to them, when congealed, ether, 

 drop by drop. A jelly-like mass is then formed, which is passed rapidly 

 through a cloth, crystals soon appearing in the liquid, which may be sepa- 

 rated by filtration (Gautier). 



The crystals of haemaglobine extracted from human blood are in the form 

 either of four-sided prisms, elongated rhomboids or rectangular tablets, of a 

 purplish-red color. They are composed of carbon, hydrogen, oxygen, nitrogen, 

 sulphur and a small quantity of iron. They are soluble in water and in very 

 dilute alkaline solutions, and the haemaglobine is precipitated from these 

 solutions by potassium ferrocyanide, mercuric nitrate, chlorine or acetic acid. 

 The proportion of this coloring matter to the entire mass of blood is about 

 one hundred and twenty-seven parts per thousand. It constitutes ^-| to 

 ^ of the dried corpuscles. A solution of haemaglobine in one thousand 

 parts, examined with the spectroscope, gives two dark bands between the let- 

 ters D and E in Frauenhofer's scale. 



Treated with oxygen or prepared in fluids in contact with the air, there 

 occurs a union of oxygen with the coloring matter, forming what has been 

 called oxyhaemaglobine. There can be no doubt that the oxygen enters 

 into an intimate, though rather unstable combination with haemaglobine, and 

 this is an important point to be considered in connection with the absorption 

 of oxygen by the blood in respiration. A solution of oxyhasmaglobine pre- 

 sents a different spectrum from that produced by a solution of pure hasma- 

 globine. 



COMPOSITION OF THE BLOOD-PLASMA. 



Assuming that the blood furnishes matters for the nourishment of all the 

 tissues and organs, there should be found entering into its composition all 

 the constituents of the body which undergo no change in nutrition, like 

 the inorganic salts, and organic matters capable 'of being converted into the 

 organic constituents of every tissue. Farthermore, as the products of waste 

 are all taken up by the blood before their final elimination, these also should 

 enter into its composition. 



Most of the constituents of the blood are found both in the corpuscles 

 and plasma. It is difficult to determine all of the different constituents of 

 these two parts of the blood. It has been shown, however, that the phos- 



