166 SCIENCE PROGRESS 



an extra amount of oxygen for their complete removal during 

 the subsequent oxygen period. To take a concrete instance, one 

 suggested by Winterstein, the decomposition of a carbohydrate 

 molecule may take place in the following two stages : 



C 6 H, 2 6 = 2C S H 8 + 2C0 2 . 

 2C 2 H s O + 60 2 = 6H,0 + 4C0 2 . 



The change represented by the first equation results in the 

 formation of a third of the total CO a output, though no oxygen 

 is drawn upon whatever ; whilst according to the second equation 

 the complete oxidation of the alcohol — a " fatigue product " pro- 

 duced by the first decomposition — requires 6 volumes of oxygen 

 for every 4 volumes of C0 2 formed, or yields a respiratory 

 quotient of '6y. 



Arguing against the somewhat inconclusive evidence of the 

 existence of intramolecular oxygen, Winterstein adopts the 

 views long since suggested by Detmer, that the primary source 

 of the energy developed in living organisms is not of an oxida- 

 tive nature, but consists rather in the disintegration of highly 

 complex labile compounds, the decomposition products of which 

 subsequently undergo oxidation. That under certain conditions 

 vital energy can be developed in the absence of contemporary 

 oxidation is undoubted, for we know that certain bacteria, as 

 B. anthracis and B. tetani, live and flourish best under completely 

 anaerobic conditions. It seems very probable, also, that some of 

 the energy liberated in aerobic organisms may be of similar 

 origin, but we cannot for a moment imagine that all the energy 

 is developed in exactly the same way. Much, perhaps most of 

 it, is in all probability formed as the result of contemporary 

 oxidation. If this is the case, then a supply of immediately 

 available intramolecular oxygen is essential, and arguing from 

 the weight of evidence, which is admittedly not quite con- 

 clusive, we should provisionally adopt the doctrine of its 

 existence. 



We must now pass on to a discussion of what is actually 

 known as to the processes of oxidation in the tissues. Mention 

 has frequently been made in the above pages of the collection of 

 fatigue products in the tissues, which subsequently undergo 

 further oxidation ; but are such products matters of fact, or mere 

 figments of fancy? Some of the most interesting evidence 



