Red Corpuscles of the Blood. 33 



adjunct (vide Exp. 7) ; which goes far to prove the intimate 

 chemical union of the two substances, inasmuch as the combi- 

 nation of zinc with hsematosine yielded fatty matter to aether. 



Exp. 6 would seem to prove, that when the phosphorized 

 fatty matters of the venous blood are removed, it no longer 

 admits of being arterialized by contact with oxygen. I am 

 not inclined however to argue much on this experiment, find- 

 ing that aether, when agitated with blood, possesses the power 

 of effecting its complete disintegration ; so much so, that blood 

 which has been thus treated appears under the microscope as 

 a congeries of crystals of well-defined form, and is entirely 

 divested of its organic and corpuscular character. 



The change which takes place in order to produce the arte- 

 rial tint in the dark-coloured blood propelled into the lungs, 

 may then be stated thus. 



The vesicular corpuscles of the dark venous blood contain 

 within their cases, and in combination with haenmtosine, a 

 fatty matter charged with phosphorus. The venous blood on 

 reaching the air-cells is exposed to the action of atmospheric 

 oxygen. This gas now combines with the phosphorized fat, 

 forming carbonic acid and water, which are exhaled, and 

 phosphoric acid, which unites with the alkaline liquor san- 

 guinis. 



The liquor sanguinis forms tribasic phosphate of soda with 

 this acid, a salt possessing an alkaline reaction. This union 

 most probably occurs principally at the expense of the albu- 

 minate of soda, and is attended with results which it is not my 

 intention now to consider. Suffice it to say, that phosphoric 

 acid may be added to venous serum in quantity insufficient 

 quite to neutralize its alkaline reaction, without any immediate 

 obvious effect being produced. 



The formation of tribasic phosphate of soda as a substitute 

 for a corresponding proportion of the alkali in combination 

 either with albumen or lactic acid, is a sufficient explanation 

 of the bright colour of arterial blood as compared with 

 that of the veins, as that basic salt possesses the power of 

 brightening blood in a marked degree ; and it is not improbable 

 that the destruction of the phosphorus in the venous globules 

 also contributes to the effect. 



I have not had recourse to any quantitative examinations on 

 this occasion, for several reasons. 



Thus it is obvious that venous and arterial blood, though 

 differing in colour, owing to the action of tribasic phosphate 

 formed during respiration, are always more or less approaching 

 each other in quality under varying conditions of the organism. 

 The flow of chyle into the blood introduces a portion of phos- 



Phil. Mag. S. 3. Vol. 33. No. 219. July 1848. D 



