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D. E. SALMON. 
microbes but the cells which injure their antagonists by exhausting 
the oxygen supply. Consequently, an artificial increase of the 
oxygen supply in the tissues would simply give the microbes a 
better chance in their struggle for existence. The theory here is 
in accordance with the clinical fact stated by Dr. Curtiss, and is 
not opposed to it, as he would have us believe. 
The next objection is that “ Dr. Salmon has not made an esti¬ 
mate relating to the ventilation of the human body with oxygen 
and the relative amount consumed by the microbes and cells.” 
Here again Dr. Curtiss reasons from a false premise. The most 
careful chemical investigations show that the liquids of the inte¬ 
rior of the body contain either no free oxygen or only a trace of 
it. The cells of the body which obtain their oxygen from these 
liquids are, therefore, able to exist and perform their functions 
with this limited supply of oxygen. In other words, the living 
protoplasm seems to have such a chemical affinity for this gas that 
surrounding liquids are kept practically exhausted. The very 
recent investigations of Elilich (“ Das Sauerstoff-Bedurfniss des 
Organismus ”), made by a new method, and apparently incontest¬ 
able in their results, confirm this view and place this part of the 
theory upon a foundation which a wise man will not attack with¬ 
out mature deliberation. Equally careful studies of microbes 
show that their oxygen requirements are very different, and that 
some of them require relatively large quantities of free oxygen 
in order to multiply at all. So far, then, as investigations have 
gone in this direction, the facts discovered are in accord with my 
theory of immunity. 
The comparison between a combat in which a dog attempts 
to kill and eat a man in a well-ventilated room and the contest 
of the microbe and the animal cell in the interior of the body, 
which Dr. Curtiss next introduces, is one of the most remarkable 
arguments which it has been my fortune to see introduced into 
the discussion of a scientific question. It reminds me of the argu¬ 
ments that, only a few years ago, were hurled by certain members 
of our medical profession against the whole germ theory of dis¬ 
ease. Notwithstanding the very positive statement that “ the 
cell and microbe and man and dog present problems of warfare 
