viii. B. 2 Butler: Carbohydrate Reactions 129 



found that all the specimens of Kahlbaum's maltose, which we 

 had in the laboratory, showed the fermentations characteristic 

 of glucose, when used in fluid media. Specimens of maltose 

 were obtained from several laboratories in Manila, and all those 

 of Kahlbaum manufacture gave the same result, regardless of 

 whether the sterilization was intermittent or under pressure in 

 the autoclave. A sample of Merck's maltose was obtained from 

 the Bureau of Science which gave the fermentative characters of 

 uninverted maltose. Barfoed's test for monosaccharids was tried 

 upon the Kahlbaum and the Merck maltoses, and this seemed 

 to substantiate the idea that the Kahlbaum preparation had 

 some glucose in it. A sample of Kahlbaum's maltose which had 

 been in the laboratory for about one year was submitted to the 

 Bureau of Science for analysis. The result is as follows:'' 



(")p =121.73 



Water (per cent) 6.72 



Corrected (»)" =130°. 5 



Osazone test shows the presence of a small quantity of dextrose. The 

 sample contains other impurities, some of which are insoluble. 

 The specific rotation of anhydrous maltose should be: 



(a)p = 139^2. 



I cannot explain why Kahlbaum's preparations of maltose 

 showed the reactions of dextrose while the one specimen of 

 Merck's did not. The Merck's had been in the storeroom of the 

 Bureau of Science certainly for over a year and very likely for 

 five years. The Merck's package had not been opened, while all 

 the specimens of Kahlbaum's except one had been opened for 

 some time. I am inclined to explain the result, however, as due 

 to the inherent tendency of the maltose molecule to take up water 

 and change into two molecules of dextrose. In solid media (mal- 

 tose agar) inoculated with the nonacid strain of B. dyseuterise, the 

 change is hardly manifest as the small amount of glucose present 

 is only fermented in the depths of the stab culture, and the slight 

 reddening is confined to the line of stab and is not manifest 

 upon the surface. But in maltose-peptone solution, where all the 

 glucose present is changed and where any change is reflected 

 throughout the medium, the result is a completely red culture, 

 whereas in a parallel tube of uninverted maltose containing the 

 same bacterium it is entirely blue. If we grant that this tend- 

 ency of maltose to invert is pretty general, and I believe that 



" Analysis by R. R. Williams. 



117065 6 



