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presence of hydrogen peroxid in the cells can not, however, be accepted 
by a critical mind as a proof that it is not formed at all, since it would 
have only an ephemeral existence. By its rapid decomposition it 
would give rise to the oxygen developed by the chlorophyll bodies—a 
view which would find some support if it could be shown that the 
chlorophyll bodies are very rich in catalase. | 
While Pfeffer’s objection can not be considered a serious one, some 
better-founded chemical objections might be raised. It is a fact that 
chemistry does not show a single instance where two hydroxyl groups 
can unite to form hydrogen peroxid. Sucha process would be improb- 
able, although not impossible.* 
1 Bruhl (Ber. d. Deutschen Chem. Ges., vol. 33, p. 1710) maintains that hydrogen 
peroxid can not be asimple ‘‘ bihydroxyl’’ HO—OH, but that the formula HO =OH 
would correspond better with its behavior, since it is free of electric absorption and 
shows a very high dielectric constant. 
e 
