MARCEL NENCKI, 1847— 1901 523 



under conditions which cause a depression of the normal 

 oxidative functions of the body. In recent years considerable 

 progress has been made in the study of the chemical mechanism 

 of sugar destruction, and successful attempts have been made 

 to produce those products which had hitherto been obtained 

 only by the agency of living organism. Mention may be made 

 here of Buchner's researches on cell-free fermentation, and 

 Duclaux's researches on the production of alcohol from sugar 

 in the presence of sunlight. Lastly, in a very recent number of 

 the Zeitschrift fur physikalische Chemie, Schade has demonstrated 

 that dextrose in the presence of alkaline carbonates decomposes 

 into acetaldehyde and formic acid : 



C 8 H w 6 = 2(CH 3 • CHO + HCOOH). 



Furthermore, formic acid in the presence of rhodium, acting 

 as a catalyst, decomposes into hydrogen and carbonic acid gas, 

 and the former body acting in nascent condition on the acet- 

 aldehyde, reduces it to alcohol. In this way the production of 

 alcohol by fermentation is explained. On the other hand, in 

 presence of caustic alkalis, the main product is lactic acid, and 

 this body is not the result of an oxidation of sugar, but of 

 hydrolysis. This confirms Nencki's results, who showed that 

 lactic acid could also be formed from sugar in the absence of 

 oxygen. The production of different bodies from sugar by 

 action of the carbonates and hydroxides is, according to Schade, 

 analogous to the production of ketones and acids from substi- 

 tuted ethylacetoacetates — either one class of body or the other 

 predominates, according to the concentration of the different ions 

 present. 



Nencki attempted to apply his results on sugar destruction 

 to the elucidation of the pathogenesis of diabetes mellitus. 

 It was considered possible that the sugar elimination was a 

 consequence of the insufficient quantities of alkalis in the body. 

 It was shown, however, that administration of bodies such as 

 sodium citrate and sodium lactate, which are readily converted 

 by the organism into the carbonates, causes no diminution 

 of the sugar output in diabetes. Nencki then sought, but 

 without success, to isolate sugar-destroying enzymes from 

 different organs of the body ; and, if we except the results of 

 Stocklasa and the somewhat doubtful results of Lepine and 

 Cohnheim, but little progress has been made in this direction 



