THE ENERGY OF THE LIVING PROTOPLASM. 



177 



time subsist on intramolecular respiration, as Pfliiger has observ- 

 ed in frogs, and Bunge in worms.' 1 ' 



Although the comparison of respiration with direct com- 

 bustion was close at hand, still there were many mysteries 

 involved and many questions unsolved, in regard to the laws and 

 to the causation of that energetic combustion going on at rela- 

 tively low temperatures in a substance containing 75 per cent 

 water and more, and yet remaining apparently intact, while 

 effecting the union of the resorbed food with free oxygen. That 

 the protoplasm remains alive while this fierce and destructive 

 oxidation is carried on, appears the more notable as it is known 

 how easily all kinds of living cells are killed by oxidising media 

 in high dilutions, as by peroxide of hydrogen or by potassium 

 permanganate. 



The views propounded by various authors exhibit conside- 

 rable discrepancy. The oldest hypothesis, that of ScJwnbein, 

 assuming the formation of ozone, had soon to be discarded. But 

 nevertheless, the idea that the common oxygen had to be changed 

 into an active form or modification before it could unite with the 

 compounds in the cell, prevails also in the other theories. The 

 supposed activifying process consisted in the splitting of t lie 

 oxygen molecule into its two atoms with free affinities. (2) Hoppe- 

 Scyler supposed that the living cells produce hydrogen, which in 

 its nascent state could accomplish the " activifying" process by 

 combining with one of the atoms and setting the other free. But 

 it was objected that hydrogen ought to make its appearance at the 

 moment oxygen is being withdrawn. This was, however, never 

 observed. Germinating seeds can exist one day, certain worms 

 (Ascaris) even 5-7 days, alive in absence of oxygen, but no trace 

 of hydrogen is evolved by these organisms during that time. (3) 

 Rcinke holds that there exist in the living cells easily oxidisable 

 organic matters, " autoxidisers," which are capable of suffering 



(r) With insufficiency of oxygen, animals will show albumen, glucose, and lactic 

 acip in the urine (Araki), also an increase of oxalic acid (Realc and Boeri). 



(2) This process would require a large amount of energy. Heat alone can 

 accomplish it only at a temperature not lower than 1400 C. (Troost and Haute 

 fcuille). 



(3) M. Traitbc contends, moreover, that nascent hydrogen can activify oxygen ; 

 it can merely produce peroxide of hydrogen. 



