THE CONNECTION OF OXYGEN RESPIRATION 8 1 



of nutrient substances (?!), especially oxygen."^ Brefeld and 

 Sachs concurred in this opinion. Thus, for example, Sachs 

 makes the following unequivocal statement: "I draw the 

 conclusion, which Nageli and Borodin have already reached in 

 another way, that the formation of alcohol in the absence of 

 oxygen is an absolutely abnormal process which has nothing to 

 do with ordinary respiration." The investigations of Muntz 

 which have already been mentioned [p. 54] refute all these ideas. 

 The experiments of Amm, Chudiakow, Palladin and Morkowin, 

 which are cited in section II, prove beyond doubt that there 

 can no longer be the question of anaerobic respiration in the 

 sense of an abnormal phenomenon preceding death. 



The credit for having carried over Pfliiger's theory of the 

 connection of anaerobic with normal respiration into the sphere 

 of plant physiology belongs to Pfeffer.^ Because he was 

 acquainted with the work of Pasteur, Lechartier and Bellamy, 

 Muntz, de Luca, and Brefeld, he was compelled to take into 

 consideration the fact that alcohol is formed in the anaerobic 

 respiration of plants. Pfeffer believed the connection of 

 anaerobic with normal respiration to be capable of definition 

 in the following simple manner. In alcoholic fermentation 

 only a third of the carbon contained in the sugar molecule is 

 liberated in the form of carbon dioxide, as appears from the 

 equation 



CeHioOe = 2CO2 + 2CH3— CHoOH. 



On the basis of this calculation PfefTer assumed that one-third 

 of the carbon dioxide formed in the process of oxygen respira- 

 tion is to be traced to anaerobic transformations of material 

 i.e. to alcoholic fermentation. The remaining two-thirds of 

 the total amount of carbon dioxide is formed by the oxidation 

 of alcohol. In this communication of Pfeffer only theoretical 

 considerations, not experimental results, are set forth. At that 

 time it was not known whether anaerobic respiration is actually 



' Nageli believed that the admission of oxygen only promotes fermentation. How Nageli 

 resisted every acknowledgment of anaerobiosis is evident from the following words with 

 which he stated his attitude toward the discovery of butyric acid fermentation. In the 

 opinion of Nageli this discovery of Pasteur depends "auf unrichtiger Beurteilung mangel- 

 hafUr Beobachtttngen" (on false judgment of faulty observations). Cf. Theorie der Garung. 



1879. P. 71. 



2 Pfeffer, W. Landwirtschaftl. Jahrb. 7: 805. 1878. 



6 



