398 OF RESPIRATION. 



tissues enter the blood, arid there meeting with the loosely combined oxygen, 

 abstract it from the corpuscles, which readily surrender it to the more oxi- 

 dizable materials. In the one case, the oxidizing process and the production 

 of Carbonic acid would take place chiefly in the tissues, in the other chiefly 

 in the blood. Various circumstances seem to point to the former as being 

 the more correct statement of the facts. 1 In the first place, the respiration 

 of the tissues shown to occur by Liebig and P. Bert, leads to the develop- 

 ment of Carbonic acid within them, and as they contain (at least in the case 

 of the most important of all the muscles) no oxygen capable of being re- 

 moved by exhaustion, the oxygen contained in arterial blood will in obedi- 

 ence to physical laws diffuse into the tissues, and be replaced by Carbonic 

 acid. Again, it may be shown that arterial blood loses its oxygen with ex- 

 traordinary rapidity during its passage through the capillaries, and although 

 this was attributed by Schmidt to the presence of easily oxidizable or redu- 

 cing substances in the blood, chiefly associated with the corpuscles (Afouas- 

 sieff), yetPfliiger 2 has shown that the quantity of these oxidizable sub- 

 stances can be but small, since arterial blood removed from the body only 

 slowly acquires a venous character, whilst even in the case of asphyxiated 

 animals, warmth and time are required for the production of a large amount 

 of Carbonic acid ; and so too, if an easily oxidizable substance, as sodium 

 lactate, glycerin, or caproic acid, be added to blood after withdrawal from 

 the body, no augmentation in the amount of Carbonic acid is observed, though 

 if injected into the circulation such substances are quickly decomposed, and 

 cause increased evolution of this gas. 3 The fact noticed by Ludwig and 

 Hammarsten, that the tension of the Carbonic acid in the lymph is lower 

 than in venous blood, though higher than in arterial, constitutes no valid 

 objection to the view that the gas is chiefly formed in the tissues and not iii 

 the blood, since the lymph examined by them had already had the oppor- 

 tunity of equalizing the tension of its gases with those of arterial blood in 

 traversing the lymphatic glands and the lacunse of the connective tissues. 

 At the same time, -the phenomena of oxidation are materially affected by the 

 integrity of the blood-corpuscles, since these are the carriers of the oxygen, 

 or perhaps, more properly speaking, of ozone; for, as Hitter 4 has shown in 

 his investigations on the influence of agents which modify the absorptive 

 capacity of the globules for oxygen, the secretions undergo material altera- 

 tions when the corpuscles have been profoundly altered by the action of 

 antimonial and arsenical compounds, by phosphorus, or by the action of the 

 biliary acids; these agents changing the form of the globules, and causing 

 the appearance of crystals of Haemoglobin in the blood, coinciding with 

 which the urine becomes albuminous, and contains various coloring materials. 

 In connection with this, the observations of Manasseiu 5 may be mentioned, 

 as showing that the red corpuscles diminish in volume when under the influ- 

 ence of abnormal activity of the disintegrating processes, as in febrile states, 

 when they have to part with an increased amount of oxygen ; or when any 

 obstacle exists to the absorption of oxygen, as when they are exposed to the 



1 See J. Worm Mullcr, in Luchvig's Arbciten, 1870, p. 168. Ueber die Spanning 

 des Sauerstoffs der Bhitschciben. 



2 Pniiger, Ueber die Diffusion des Sauerstoffs, etc., Pfliiger's Archiv, Bd. vi, 1872, 

 p. 4:;. 



3 Ludwig and Schremetjewsky (Ludwig's Arboiton, 18G8) have, however, shown 

 that sugar passes through the capillaries of the kidneys unchanged. 



4 Hitter, Des Modifications cbimiques que subissent les secretions sous 1'influence 

 dc, (|ui'li|ucs agents qui modifiunt les globules sanguins. Paris, 1872. See Kiiss, 

 Physiologie, p'. 380. 



6 UVbt-r die Diiucnsioncn der rothen Blutkorpcrchen unter verschicdencn Einflus- 

 sen. Pamphlet, 1872. 



