344 PLANT AND ORGANIC CHEMISTRY 



metrical configuration of the ferment coincides with that of 

 the compound which it attacks. The most important chem- 

 ical agents of the living cell are the optically active ones of 

 the albuminoids, and these possess, consequently, an asym- 

 metrically constructed molecule. Since the simple albumi- 

 noids result from the sugars, the fact is given in proof of the 

 same geometrical structure for these two classes of bodies. 

 On this reasoning it has been claimed that, when sugar comes 

 into contact with the albumen of the yeast cells, fermentation 

 takes place only if the geometrical form of the sugar molecule 

 does not differ too widely from that of the yeast substance. 



In some recent experiments, Fischer found that the fer- 

 ments invertin and emulsin attack only the glucosides of grape 

 sugar, whilst they leave those of other sugars likewise 

 starch, salicin, phlorizin, and other synthetical phenol-glu- 

 cosides unacted on. 



However, the a-methyl glucoside is decomposed by inver- 

 tin and not by emulsin; but with the methyl-glucoside the 

 reverse occurs. These facts are given to show that a different 

 molecule structure alters the condition. 



The influence of the bacilli on chemical changes in the 

 body is recognized. That these changes do occur is evident. 

 Many experiments on plant tissues show this. The transfor- 

 mation of starch into sugar by the Bacillus anthracis has been 

 shown lately by cultivating the bacillus on a potato. After a 

 short time, the surface of the potato gave, not the blue color 

 of starch with iodine, but the red color of dextrin. Portions 

 of the potato were then placed in sterilized water, and, after 

 some days, on testing the liquid, it reduced Fehling's solution. 

 The explanation of these changes is supposed to rest on the 

 configuration of the molecule. 



From the survey of the chart, on which are summarized 

 the synthesis and work on the sugars, the attention of the least 

 interested observer will be called to this fact, that a vast 

 amount of work has been accomplished in this field, and the 

 harmony in these groups between facts and theories is signi- 

 ficant. That chemical compounds are solids and occupy space 

 is not to be gainsaid, but there must be an adjustment between 



