Physiology," page 537, says: "Most of the studies have b»en made solely by 

 determinations of the quantities of carbon dioxide given off in respiration, 

 the results being taken as standards for the relative volumes of oxygen ab- 

 sorbed ; but such deductions are of very uncertain value, and may be entirely 

 misleading." 



With such authorities leading the way to doubt, it is not presumptuous 

 to turn to new lines of reasoning to find rational explanation for the vital 

 phenomena taking place in the human system. Consequently I offer the fol- 

 lowing analysis of the existing conditions, with a feeling that it will bear the 

 most exacting tests. 



In the human lungs two great circulations meet — that of the blood, and 

 that of the atmosphere. These circulations moving in opposite directions, 

 bring together elements which have mutual attraction. Under the influence 

 of heat these elements unite— generating electro-chemic energy, which puri- 

 fies the blood, and thus sustains the life of the organism. 



That oxygen and carbon are found in the chemical constituents of the blood 

 can not be denied; but that these elements reach it by a process of osmosis 

 is indeed very questionable. Neither can it be shown in a single instance 

 that these elements unite in any form while they are circulating in the blood. 

 In the course of analysis, it will be shown that the supply of oxygen and of 

 carbon found in the blood and tissues reach the system through the route of 

 digestion. 



A strong argument against the theory of osmosis, or diffusion of gases lies 

 in the fact of the greater resistance offered by living membranes, and by the 

 pressure of the blood exerted against that of the atmosphere. The proof of 

 greater pressure is shown by the hemorrhage which results if the smallest 

 opening is made in the air-sac of the lung. Notice how carefully Nature 

 guards the possibility of hemorrhage in tubercular lungs, by infiltrating large 

 areas about the point of infection. Another instance is seen in the provision 

 of an artery for the passage of venous blood from the heart to the lungs — the 

 only place in the human system where an artery is used for the conveyance of 

 venous blood. 



In regard to filtration or osmosis, Howell says, in "The American Text 

 Book of Physiology," page 156: "It has been shown that living membranes 

 offer considerable resistance of filtration, even when liquid pressure on one 

 side is much greater than on the other. Tigerstedt and Santessen, for in- 

 stance, found that a lung taken from a frog just killed gave no filtrate when 

 its cavity was extended by liquid, under a pressure of 18 to 20 centimetres — 

 provided the liquid used was one that did not injure the tissues. If, how- 

 ever, the lung tissue was killed by heat or otherwise, filtration occurred 

 readily under the same pressure." 



In my own experiment on fresh lungs from the sheep, I have repeatedly 



