GENERAL CHEMISTRY OF LIFE PHENOMENA 23 



of oxygen were produced from glycogen or sugar. If this be correct, 

 a process must, under such conditions, occur which bears a certain 

 resemblance to the alcoholic fermentation of sugar, although in the 

 place of alcohol another product may be formed. 



It was remarkable that in spite of these observations and the well- 

 known fact that the muscles are the main seat for the production of 

 CO 2 , nobody was able to show that a muscle extract is able to decompose 

 dextrose. This gap seems to have been filled recently by Cohnheim.* 

 Von Mering and Minkowski had found that extirpation of the pancreas 

 causes the most serious type of diabetes. This fact and subsequent 

 discoveries suggested that the pancreas must secrete a substance into 

 the blood, by which the oxidation or cleavage of sugar is accelerated. 

 The place of the decomposition of the sugar must evidently be the 

 muscles. Starting from these arguments, Cohnheim tested whether 

 the muscle and the pancreas together do not contain a glycolytic power 

 which neither contains alone. Cohnheim succeeded in showing that, 

 by a process similar to that used by Buchner, liquids free from cells 

 can be extracted from muscles and pancreas which, if mixed, cause 

 dextrose, when added to the mixture, to disappear from it. The liquid 

 extract from the muscle or the pancreas alone has no such action. "This 

 observation may be analogous to the discovery of Pawlow, that the 

 mucous membrane of the intestine secretes a substance, enterokinase, 

 which activates the trypsinogen of the pancreatic juice, or to the observa- 

 tion made in the case of the hemolysins by Bordet and Ehrlich, that 

 this process requires two different substances, - - the so-called comple- 

 ment and Zwischenkoerper." 



All these facts show that the production of CO 2 in the body may 

 occur without the presence of free oxygen, that these processes are 

 evidently accelerated by special enzymes. 



In regard to the energetics of these processes, it may be said that 

 the energy which can be obtained by the complete oxidation of dextrose 

 is about ten times as large as that which can be obtained from it by 

 alcoholic fermentation. Bunge has calculated that it would not be 

 possible for a man to do the average amount of muscular work at the 

 expense of energy derived solely from the alcoholic fermentation of 

 sugar. For this process the oxidation of dextrose is necessary, and 

 therefore the presence of oxygen is required. 



* O. Cohnheim, Hoppe-Seyler's Zeitsch. fur physiol. Chemie, Vol. 39, p. 336, 1903. 



