260 



OF THE BLOOD: 



The percentage proportion of the gases of the blood amongst themselves, 

 obtained from the mean of seven observations of Meyer and Setschenow, is 



Oxygen, 

 Nitrogen, 

 Carbonic Acid, 



2820 



7.10 



64.70 



100.00 



In all experiments made to determine the proportions of the gases of the 

 blood, the investigation should be commenced immediately after the blood 

 has been withdrawn ; since it is certain that the quantity of oxygen decreases, 

 and of carbonic acid increases, with considerable rapidity. Thus Felix 

 Nawrocki 1 found the following differences in two equal and similar portions 

 of blood drawn at the same time, one of which (I) was examined immedi- 

 ately, and the other (II) after the lapse of 24 hours, the mean temperature 



of the air in the room being 86 F. 



CO 



1!' 



I. 



34.66 



7.72 

 1.97 



II. 



40.95 

 1.02 

 0.67 



44.35 



42.64 vol. in 100 of Blood. 



MM. Mathieu and Urbaiu 2 found that whilst blood taken from arteries of 

 the same size contained equal amounts of oxygen, the proportion of this gas 

 was slightly (2 or 3 per cent.) diminished in blood drawn from the smaller 

 vessels. 3 Hirschmann, however, found no remarkable differences in the 

 blood of different arteries. The variations which occur in the venous blood 

 returning from muscles at rest and in action, as compared with the arterial 

 blood of the same animal, are well shown in the following results obtained 

 by Sczelkow, 1 where A indicates Arterial blood, MR the blood returning 

 from muscles at rest, and MA that returning from muscles in action : 



1 See Studien des Pbysiolog. Institut zu Breslau, 1863, p. 144. 



2 Op. cit., p. 200. 



3 Hirschmann, Journal do 1'Anatomie, 1865, p. 302. See also Estor and Pierre, 

 Arcbiv f. Anat. u. Physiol., 1866, p. 602. 



4 Sitzungsbericht d. Wiener Akacl., Bd. xlv, 1862. 



