CHEMICAL PROPERTIES OF ADRENAL, SECRETION. 75 



lace and Mogt, 150 of Ann Arbor, found that, while suprarenal 

 extract caused a rise in the systemic blood-pressure due to the 

 contraction of the arterioles, the pressure in the pulmonary 

 arteries was not raised, these vessels, in their opinion, not being 

 acted upon as are the others. Velich, 151 on the other hand, 

 found, by a series of experiments instituted to ascertain whether 

 vasoconstrictor fibers exkted for the pulmonary vessels, that 

 suprarenal extract gave rise to but a slight rise of pressure: 

 a result which led him to conclude that the existence of a spe- 

 cial vasoconstrictor mechanism, either central or peripheral, 

 for the pulmonary circulation, could not be considered as estab- 

 lished. Warm suprarenal extract, which, when applied even to 

 the skin, causes pallor, was found by him to exercise no such 

 effect upon the surface of the lungs. Briefly, upon all other 

 tissues the effects of suprarenal extract are strongly marked; 

 as soon as the pulmonary structures where the conversion of 

 venous blood into arterial blood occurs are reached, its powers 

 practically cease. 



True, the physiology of respiration as at present interpreted 

 in text-books and as generally taught would not be sustained. 

 This does not mean, however, that all physiologists have finally 

 accepted the prevailing doctrine based on the diffusion of gases. 

 Indeed, there is considerable experimental evidence based on 

 the labors of Eobin, Bohr, Miiller, and others to show that it 

 is by no means invulnerable. "When," says Prof. Mathias 

 Duval, 152 of Paris, "an animal is caused to breathe in the 

 smallest possible space the air imprisoned in its lung by 

 strangling it uses up all the oxygen of this air. This is be- 

 cause hemoglobin, in virtue of its chemical affinity, takes up 

 the oxygen as fast as this gas is dissolved in the serum, so that 

 the latter, always despoiled, is never able to satisfy its absorp- 

 tion coefficient for oxygen, however low be this coefficient, and 

 however slight be the tension of the oxygen in the surrounding 

 air. As to the exhalation of carbonic acid, it is not produced 

 in so simple a manner as would a priori seem, by mere gaseous 

 diffusion or by the mere giving off of a gas in solution, because 



160 Wallace and Mogt: Transactions of the Physiological Society, Dec. 28-30, 

 1898. 



151 Velich: Wiener med. Wochenschrift, No. 26, 1898. 



152 Mathias Duval: Cours de Physiologic, Ed., 1892.. 



