Studies of the processes operative in solutions. XXI.—The hydrolysis of cane sugar by dilute acids

In Part XII of these studies an account was given of a close and extended study of the hydrolysis of cane sugar by means of chlorhydric and nitric acids in aqueous solution and of the influence of corresponding salts on the rate of change. In the course of the investigation, not only were unexpected sources of error discovered in the method used by previous workers in reducing their observations but it became obvious also that the accepted views by which enquirers in this field have been guided hitherto need modification in essential respects. It was pointed out, in particular, that the usual method of applying the mass action equation, to say the least, is not the best: besides a possible general error due to an incorrect initial reading, it gives a spurious constancy to the values of K, making it difficult to detect actual departures from the unimolecular law; it was shown that the following is a better form of equation to use:— K loge = 1/t 2 -t 1 log10 a -x 1 /a -x 2 , in whicha —x 1 anda —x 2 are the sugar concentrations at timest 1 andt 2 respectively, successive equal intervals of time being taken as small as the accuracy of the observations allows or the rapidity of the change demands.