1904.] ly d- and l-Camphor-ft-Sufyhonic Acid. 185 



laevo acid j in the second set, the value obtained for the dextro acid 

 was 9-87, that for the laevo acid being 9'99. 



Slight variations in the temperature would account for such 

 differences, as the influence of temperature on the rate of change is 

 known to be very great. But even in these experiments the variations 

 observed are small and not such as to suggest any substantial difference 

 between the two acids. In the last set of observations, fully set forth 

 in the table on p. 187, which there is every reason to regard as 

 satisfactory, there is clearly no evidence of a difference in the activity 

 of the d- and /-acids to be noticed. 



The results, therefore, riot only confirm the conclusion arrived at by 

 E. Fischer, but are also in agreement with the observations of Marckwald 

 and Chwolles,* that methylic d- and /-tartrates are hydrolysed with 

 equal readiness by /-nicotine (at 17 '5 and 40 C.). On the other hand, 

 they are in remarkable contrast with the conclusions of Marckwald 

 and McKenzief and of McKenzieJ that ethereal salts similarly derived 

 from optically active isomeric compounds are both formed and 

 hydrolysed at different rates. It is to be noticed, however, that the 

 experiments of these chemists were carried out at relatively high 

 temperatures and that they involved racemisation. 



An experiment made with chlorhydric acid and cane sugar under 

 conditions precisely similar to those prevailing in Experiments V VIII, 

 using a solution containing 17 '6 per cent. (0'5 gramme molecule) of 

 cane sugar and 0'486 gramme molecule of hydrogen chloride, gave the 

 value K= 11-18. 



Representing the activity of hydrogen chloride as 100, that of 

 camphor-/3-sulphonic acid is therefore 89*8, which is a value in accord 

 with that assigned by Ostwald to ethylsulphonic acid, viz., 91*2. 



In the preliminary stage of the inquiry, a comparison was also made 

 of the action of chlorhydric acid and of 6?-camphor-^-sulphonic acid 

 on milk sugar at 60'l. The value obtained for the former was 

 K = 3'53. The values observed in the case of the camphor-acid were 

 as follows : 



* ' Ber.,' 1898, vol. 31, p. 783. 



f * Ber.,' 1899, vol. 32, p. 3120. 



j ' Chem. Soc. Trans.,' ]904, vol. 85, p. 378. 



' Boy. Soc. Proc.,' vol. 73, p. 532. 



P 2 



