( 10 ) 



«I toinperjiliii'C. Ordiiiarv lacviilose in soliiliou is as a rule less slal)le 

 tljaii glucose. In iiiverliii a (lilierence in (lie same direetioii is 

 also nsually revealed. Drviiiii' at loo liiuli a leiiiperaliire, healing (he 

 "kieselgnhr"" mixture above 100 , or preeipitalion with aleohol and 

 redrying (he i)i'eci[)itated enzyme, repeatedly gave invertin, the action 

 of which is retarded considerably more by laevnlose than by glucose. 

 Active laevulose tluM-efore generally becomes inert sooner than 

 active glucose. 



This explains the diiference between my results and those of 

 Victor Hknri *) who states: 



"Pour I'addition d'une nieme quantité de sucre intervcrti, le ralen- 

 tissement est d'autant plus faible que la concentration en saccharose 

 est plus grande. Ce ralentissement est prodnit presque uniquement 

 j)ar le lévulose contenu dans le sucre interverti." 



Probably, Henri has obtained his invertin from yeast dried at more 

 elevated temperatures or has used commercial invertin, prepared by 

 precipitation with alcohol. That the retardation of a same quantity 

 of invert sugar becomes smaller when the canesugai' concentration 

 becomes greater is ipiitc in harmony wiih (he radiation theory. The 

 fact that (he laevulose cond-ibuted mos( (o that i'e(ai'da(ion was oidy 

 a pathological pheiiomrnon of the imertin. 



We must fui'thcr bear in mind the possibility that, owing to those 

 harmful actions, the radiation ge(s so weakened that the reversion 

 can no longer take place, or that the radiating <^(-glucose has been 

 converted into radiating j'J-glncose and also that oidy the latter is 

 capable of inverting. It is certainly to be expected that, if only active 

 glucose or actise laevulose is left behind, the power of causing 

 reversion has either decreased or been destroyed. 



In order to counteract the lirst cause of the non-aj)pearance of 

 the reversal, namely, the secondary conversion of «-glucose into 

 /?-glucose, we may ai)ply much enzyme and so accelerate the con- 

 version, A larger quantity of extract of the above yeast, which had 

 been finally dried for half an hour at 100", caused indeed a slower 

 inversion of the last remaining percentages of canesugar. 



The reversed action was afterwards noticed more distinctly 

 with ordinaiT yeast, merely dried in vacuum at about 30^. We 

 will first give a mathematical formulation of the ])henomena to 

 be expected. 



Let us imagine an aqueous solution of invert sugar, liable to 

 reversal and consequently containing the glucose in the «-form, in 



1) C. R. 1902 Nov. C4 917, 



