( ^55 ) 



the experiments recorded in table 3 had been kept for two weeks 

 in a closed bottle at the ordinary temperature. It is not improbable 

 that in the latter liquid the quantity of saccharate was a larger one ; 

 on heating the same no, or but very little, Ca(OH)j was copre- 

 cipitated with the saccharate, so that the decomposition velocity of 

 the saccharate was but trifling. 



On the other hand the liquid of the experiments of table 2 con- 

 tained less sacchaiate and more Ca (OH)^ in the cold solution so 

 that, on warming, calcium hydroxide was at once coprecipitated 

 which, by catalysis, promoted the decomposition of the saccharate. 



This is also coufirnied by a comparison of the results in table 3 

 and n°. 1 of table 4. The experiments of table 4 were carried out 

 with the same liquid as that of table 3, but a week earlier. The 

 quantity of trisaccharate precipitated in n". J of table 4 was smaller 

 than that in n°. 1 and 2 of table 3 as is also shown plainly from 

 the polarisations of the liquid phase. 



This we will also connect with another phenomenon which we 

 have observed. When, in a cold lime-containing clear sugar solution 

 we determine the amount of lime by titration and then repeat the 

 same after the solution has stood for some time, it appears that the 

 alkalinity has diminished although the solution is still perfectly clear. 



Probably, in the case of cold solutions, the inner equilibrium in 

 the liquid sets in very slowly ^) and the quantity of saccharate 

 influences the results of the titi-ation. 



The decomposition of the dissolved saccharate by dilute acid 

 would consequently not take place immediately at the ordinary 

 temperature. A further investigation of this phenomenon is very 

 much to be desired, as it is of great importance to known in how 

 far the usual technical lime titration process is correct or not. Very 

 probably, the titration of a dilute solution onl}- just cooled gives 

 correct results, but the alkalinity determination in more concentrated 

 solutions and juices deserves in this respect a closer investigation. 

 We intend carrying out further supplementary researches as to the 

 decomposition of the trisaccharate at 80°. Particularly, the deter- 

 mination of the line FG (fig. 1) is for several reasons of great 

 importance. We have, however, postponed these experiments when 

 we noticed that the condition of the cold lime-containing liquid 

 exerted an influence on our results. 



Hence, we will first endeavour to gain some knowledge, as far 



1) In fact, by repeated treatment of sugar solutions, of average concentration, 

 with lime, solutions of a very high alkalinity may be obtained. But we cannot 

 pretend that such solutions are saturated. 



