44 A Manual of Veterinary Physiology. 



phuretted hydrogen, iron salts, etc. The proportion of 

 oxygen in the blood bears a relation to the amount of iron 

 contained by the hemoglobin. 



Blood exposed to the air loses oxygen, due to decomposi- 

 tion leading to the production of reducing substances. 



It has been supposed, owing to the readiness with which 

 haemoglobin parts with its oxygen, that the latter must be 

 in the form of ozone (Hermann) ; but this view is, however, 

 incorrect. 



The Carbonic Acid in arterial blood is about 39 per 

 cent. ; in venous blood it varies, depending on the vessel. 

 The C0 2 is principally united to the sodium carbonate in 

 the plasma of the blood. 



The Nitrogen in the blood is small in amount, about 

 2 vols, per cent. ; it does not vary in arterial or venous blood, 

 as in both cases it is simply absorbed by the plasma ; 

 though Fernet and Setschenow* consider that a small 

 portion of it is chemically combined in the blood-cells. 



Chemical Composition of the Blood. — The following are the 

 analytical tables of the blood of animals furnished by 

 various authors. I have omitted a very large series given 

 in Simon's ' Chemistry,' from analyses made by Nasse, and 

 also Lehmann's analyses, published in his ' Physiological 

 Chemistry,' as the results do not compare with those 

 obtained in more recent periods, by probably more accurate 

 methods of inquiry : 



Hoksk. 



100 parts by weight of blood contain : 

 Blood corpuscles, 34*418, containing 12-8 per cent, of Bolids. 

 Plasma, G5'582, „ 10'0 



(C. Schmidt, Landois, and Stirling.) 



* Hermann's ' Human l'li\ siolog} ' ((iamgee). 



