184 Mr. K. J. Caldwell. Hydrolysis of Cane Sugar [June 16, 





[D 7050.] 



" Hydrolysis of Cane Sugar by d- and /-Camphor-/3-Sulphonic 

 Acid." By KOBERT JOHN CALDWELL, B.Sc., Clothworkers' 

 Scholar, Chemical Department, City and Guilds of London 

 Institute, Central Technical College. Communicated by 

 Professor H. E. ARMSTRONG, F.E.S. Eeceived June 16, 1904. 



The study of the action of asymmetric hydrolytic agents on the 

 sugars acquires interest from the fact that enzymes, which exhibit 

 most remarkable activity as hydrolysts, are apparently all asymmetric 

 in structure. The only experiments of the kind made hitherto are 

 those by Emil Fischer,* on the action of d- and /-camphoric acids on 

 cane sugar, described in his memoir on the importance to Physiology 

 of Stereochemistry. No difference was detected ; but as the experi- 

 ments were made at 90 C. in sealed tubes, it was desirable to extend 

 the inquiry and to operate under conditions more nearly comparable 

 with those under which enzymes act. 



At Professor Armstrong's suggestion, the acids selected for the 

 purpose were the two isomeric acids of opposite activity prepared by 

 direct sulphonation of d- and /-camphor by Keychler's method. They 

 are easily prepared and they act quickly, so that their action can be 

 studied at atmospheric temperatures ; moreover, as concentrated 

 solutions can be used, even a small difference in their activity should 

 riot escape detection. The inversion was carried out in a polarimeter 

 tube enclosed in a jacket through which a flow of water was main- 

 tained varying in temperature by only 0'05 from 20 '05 C. 

 Readings of a D were taken at intervals of 15 minutes. The results 

 obtained are entered in the following tables, in which a is the amount 

 of cane sugar per litre of solution when the first reading was taken and 

 a-x the concentration of the solution, at other times t minutes after 

 the first reading. The strength of the acid in all cases was 0-488 gramme 

 molecule per litre, as determined by titration with alkali. The 

 concentration of the sugar solution used was 17*1 per cent. (0'5 gramme 

 molecule). The rate of change was such that the inversion was about 

 half completed at the end of six hours ; the end point was determined 

 in Cases I and II after 48 hours standing at 20 C. 



Although there cannot have been any great difference in the 

 conditions in the different experiments, the results must not all be 

 included in one series, as the temperature regulator was readjusted 

 if ter the first and after the fourth experiment ; they are therefore tc 

 be considered in three sets, viz. : I: II, III, IV: V, VI, VII, VIII. 



The first set gave K = 10-02 for the dextro acid 'and 9-95 for the 



* ' Zeits. Physiol. Cliein.,' 1898, vol. 26, p. 83. 



