RESPIRATION. 



361 



conditions of the red corpuscles can be changed 

 by the action of various agents, such as pure 

 water, and solutions of certain neutral salts. 

 By the action of the former, the corpuscles 

 swell, become more globular, and reflect less 

 light ; by the action of the latter, they become 

 smaller, thinner, somewhat bent and notched, 

 and reflect more light. These changes are 

 apparently dependent upon endosmotic and 

 exosmotic currents, between the fluid contents 

 of the red corpuscles and the surrounding 

 fluid. It has been maintained that the red cor- 

 puscles of venous and arterial blood differ in 

 their external form, the former approaching 

 in their shape those acted upon by water, the 

 latter those subjected to the action of solutions 

 of the neutral salts ; and this change in the 

 form of the corpuscles has been adduced as 

 the cause of the difference in colour between 

 arterial and venous blood. Kaltenbrunner *, 

 Schultzf, H. Nassej, SchererJ, Reuter ||, 

 Mr. Gulliver 1", and Harless **, have de-_ 

 scribed various differences in the external 

 form of the red corpuscles of the two 

 kinds of blood, as observed by them under 

 the microscope, from which some of them 

 infer an increase in their power of reflect- 

 ing light ff; while Burdachjf, Miiller$, 

 Bruch || || , and Marchand 1[1", have failed in de- 

 tecting by the microscope any difference in their 

 external form in the two kinds of blood.*** 

 Those observers who have described differ- 

 ences in the shape of the red corpuscles in 

 arterial and venous blood do not quite agree 

 in their account of these. They agree, how- 

 ever, in this, that the red corpuscles are 



* Experimenta circa Statum Sanguinis et Vaso- 

 rum in Intiammatione, p. 71. 1826. 



f Das System der Circulation, S. 27. 1836. 



j Handwb'rterbuch der Physiologie, von Wagner, 

 Band i. S. 97. 1842. 



Zeitschrift Fur Rationelle Medizin. Herausge- 

 geben von Henle und Pfeufer, Band i. heft ii. S. 288. 

 1843. 



|| Idem opus, Band iii. heft ii. S. 165. 1845. 



^[ Work of HeAvson, printed for the Sydenham 

 Society, note at p. 9. 1846. 



** Monographie uber den Einfluss der Gase auf 

 die Form der Blutkorperchen, von Rana temporaria. 

 Erlangen, 1846. 



ft We have not included, for obvious reasons, 

 among these authorities in favour of there being a 

 difference in the shape of the red corpuscles in the 

 two kinds of blood, those authors who, like Henle 

 and Mulder, have adopted this view without stating 

 that they had personally investigated by the micro- 

 scope the point at issue. 



t J Traite' de Physiologie, &c. traduit par Jourdan, 

 torn. vi. p. 135, 136. 1837. 



J Elements of Physiology, translated by Balv, 

 i. p. 346. 1840. 



IHI Zeitschrift, &c. Von Henle und Pfeufer, Band 

 i.heft iii. S. 440. 1844; Band v. heft iii. S.440. 1847. 

 ^ Journal fiir praktische Chemie, Band xxxviii. 

 S. 279. 1846. 



'* Dr. G. O. Rees (Med. Gazette, Session 1844-5, 

 p. 840) maintains that the structure of the red par- 

 ticles prevents the possibility of their assuming any 

 other form than the biconcave in a fluid of the 

 specific gravity of serum, whether exposed to air or 

 not ; but this statement appears to be founded upon 

 the presumed effects of the endosmotic and exosmo- 

 tic conditions of the red corpuscles, and not upon any 

 examination by the microscope of the effects of gases 

 upon these bodies. 



more turgid and less clear in venous than in 

 arterial blood. Scherer describes the red 

 corpuscles in arterial blood as biconcave, and 

 those in venous blood as biconvex and de- 

 cidedly swollen. Mr. Gulliver states that in 

 all his experiments " the red corpuscles were 

 reduced in size, both in breadth and thickness, 

 by neutral salts, and in a less degree by sugar 

 and oxygen ; while the first effect of water 

 and of carbonic acid was to swell the cor- 

 puscles and make them more globular." Nasse 

 says that the red corpuscles of the arterial 

 blood in the mammalia, on the contact of car- 

 bonic acid gas, become muddy in the middle, 

 the ring formed by the colouring matter be- 

 comes broader, they become darker and some- 

 what thicker, at least on one side, and they 

 adhere closer together. Harlass gives measure- 

 ments of the corpuscles of the blood of the 

 frog, when brought into contact with oxygen 

 and carbonic acid, to show that they become 

 somewhat broader and thicker when exposed 

 to the action of the latter gas. He also states 

 that while the corpuscles in the former are 

 finely granulated on the external surface, those 

 in the latter are smooth. 



Theory of respiration. The actions be- 

 tween the blood and the atmospheric air in 

 the performance of the function of respiration 

 are regulated entirely by chemico-physical 

 laws. No doubt the blood and air are con- 

 veyed to and from the lungs through the in- 

 strumentality of the vital properties of the 

 nervous and muscular tissues, but the changes 

 they there undergo do not appear to be in- 

 fluenced by vitality. When venous blood and 

 atmospheric air are brought into contact out 

 of the body, the same actions apparently occur 

 as in the lungs during life, viz., the atmospheric 

 air loses part of its oxygen, acquires in its 

 place a quantity of carbonic acid gas, and the 

 blood assumes the arterial hue. The distri- 

 bution of the blood in innumerable minute 

 streamlets upon the surface of the air-cells, 

 filled with atmospheric air, affords much more 

 advantageous means than can be obtained in 

 experiments out of the body, for facilitating 

 the mutual actions of the blood and atmo- 

 spheric air. From the known rapidity with 

 which gases permeate both living and dead 

 animal membranes, the moist delicate mem- 

 branes that intervene between the blood con- 

 tained in the capillaries of the lungs, and the 

 atmospheric air in the air-cells, will readily 

 permit the endosmose of a portion of the at- 

 mospheric air, and the exosmose of a portion 

 of the gases held in solution in the blood. 



The rest of our remarks on the theory of 

 respiration maybe arranged under three heads : 

 viz. 1st, the manner in which the air in the 

 upper and in the lower parts of the respiratory 

 apparatus is intermixed ; 2dly, the nature of 

 the immediate actions between the blood and 

 atmospheric air in the lungs, in which a quan- 

 tity of carbonic acid gas appears in the expired, 

 and a quantity of oxygen disappears from the 

 inspired air; 3dly, the nature of the changes 

 the blood undergoes in passing from the venous 

 to the arterial condition. 



