4 o SCIENCE PROGRESS 



stages, which, however rapid, are isolated in time and, may be, 

 in place. One organ, we believe, may deal with some of the 

 stages and quite another organ with the later ones. 



In connexion with the conversion of sugar into fat, attention 

 has recently become fixed upon the possibility that so simply 

 constituted a substance as acetic-aldehyde (CH 3 COH) is formed 

 upon the way. The aldehyde is formed by the partial oxidation 

 of dextrose or of its derivative, lactic acid, and may be supposed 

 to undergo condensation and to give rise to fatty acids. There 

 are suggestive, if not conclusive, experimental results in support 

 of this view ; it is also in accordance with the familiar but no less 

 remarkable fact that physiological fatty acids contain always an 

 even number of carbon atoms in their molecules. This would 

 clearly be the case if condensation of a two-carbon aldehyde 

 were responsible for their formation. 



Formation of Sugar from Protein 



That sugar takes origin from protein in the body is shown 

 by the quantitative study of certain physiological phenomena, 

 especially as they occur in carnivora. The fact is abundantly 

 evident in the phenomena of diabetes. In that condition as 

 experimentally induced and in the severer cases of the disease 

 in man, over half of the total energy contained in the protein of 

 the food appears in the excreted sugar. Whether this should be 

 taken as showing that so large a proportion as this normally 

 assumes the form of sugar, the diabetic error merely bringing 

 the sugar into view ; or whether an abnormal breakdown is 

 involved in diabetes we cannot yet decide but from general 

 physiological considerations the former possibility is the more 

 likely. 



The chemistry of the transformation is, perhaps, on the 

 whole, more easy to understand than that of sugar into fat, 

 though as little decided by experiment. The administration of 

 certain of the individual amino-acids which are contained in the 

 protein molecule has been shown to increase the sugar output in 

 diabetes ; and the whole mixture of them, as obtained after 

 hydrolysis of protein, yields as much sugar when administered 

 to a diabetic dog as does an equivalent weight of the intact 

 protein. Many are now working at this type of problem and 

 there is no reason why we should not arrive at a knowledge of 



