296 E, DIVERS AND T. HAGA : 



siilpliite and acid cnibonate are intermediate products, the latter 

 of wliieli separates for a, time from concentrated solutions. We 

 liavc made fuitlier experiments to ascertain the effect of the first 

 portions of the sulphur dioxide in producing hydroximidosul- 

 ])liato, which, where alkali hydroxide is used, we have shown to 

 be insignificant. 



These experiments were carried out in the same way as those 

 for testing the effect when sodium hych'oxide is employed (I. b) 

 but with the modification of making two pipettings each time 

 instead of one, and of weighing both instead of merely measur- 

 ing them, then in tlie one we determined tlie sodium, as sulphate 

 and used tlie result for calculating what fraction of the original 

 solution the other quantity was in which we determined sulphite 

 and sulphonates. We thus made ourselves independent of the 

 chancre of volume durins; the reaction caused bv loss of carbon 

 dioxide and gain of sulphur dioxide. We found in this way, 

 admitting of no refined accuracy, that at a later sampling the 

 solution contained at most, as much as o^/o per cent, less sodium 

 than at an earlier sampling, a diffei'ence however hardly large 

 enough to need attention. 



The flask for receiving the portion for the sodium determin- 

 ation was previously weighed empty but that for the other 

 portion was weighed containing some concentrated solution of 

 sodium hydroxide, placed there to arrest all action in the pipette- 

 ful (1 topped into it. In the first portion could be seen, by its 

 changes on standing, how necessary the sodium hydroxide was 

 for fixing the composition of the solution at the time it was 

 sampled ; sometimes acid carbonate was deposited by it, some- 

 times hardly at all ; sometime« the precipitated acid carbonate 

 slowly disappeared sometimes not. The solution used contained 



