( 459 ) 



slaked lime, milk of lime c(c.) a pliasc-e(|nilil)i'iiim sets in at not 

 too low a temperature (say 80°) while the i-ea('tion-e(|uilihi'iiim sets 

 ill so slowly that the composition ol' \\\c li(|iii(l dnriiij^' the experi- 

 ment may he considered as constant. 



2. When the lime is added at a lower tem|)eratnre or when a 

 tem[)orary coolinu' of the mixture has taken place, also more lime will 

 remain in solution after heating' to 80°, than coi-responds with the 

 condition of e((nilihrinm. 



If the temperatnre was, at tirst, considerai)ly|lower trisaccharate 

 will ])recipitate at 80° (the lower the temj)eratnre has been the 

 larger the dej)Osit). The deposit will also he increased when the 

 lime added contains mncli free calcinm oxide and wheiftlie addition 

 of quick lime takes place more cautiously so as to avoid local 

 heating. In this case also, the reaction-eqnilibrinm in the liquid will 

 cilter but very slowly so that the j)hase-e(piilibriuin present appears 

 to be stable. If Irisacharate has precipitated a lime-content is found 

 corresponding with a jioint of /'ƒ/ in fig. 3. 



8. Theoretically, the duration of the reaction will exert its intlnejice 

 until the definite C(piilibriuni has set in. In practice, however, (as 

 was assumed in 1 and 2) the duration of the reaction only exerts 

 an influence until the phase-equilibrium has set in. This, however 

 only applies when no large quantities of solid calcium hydroxide 

 are present. These, at a higher temi)erature and a not too high 

 sugar concentration promote the attainment of the reaction-etiuiii- 

 brium so much that the latter will make its influence felt even with 

 a shorter duration of the exjieriment. ('laasskn's experiments furnish 

 a good illustration of this. He found ^) that the solubility, when 

 using milk of lime "zunachst mit der M enge des angewandten Kalkes 

 steigl, nnd l)ei niedrigen Temperaturen starker als bei h<")heren. Von 

 2 — 27., "/n Kalkzusatz ab bleibt die Meiige des gel()sten Kalkes ungefahr 

 gleicli Oder sinkt bei holien Temperaturen nnd 10 "/o Trockenkalkzusatz 

 sogar etwas". 



The duration of the experiments concerned was 60 minutes. That, 

 at a lower temperature, the solubility increases with the amount of 

 lime added is due to the fact that during the time of the experiment 

 the pliase-e(piilibrium was not attained, which in our opinion is also 

 confirmed b} some other of Claasskn's experiments (I.e. j). 499); at 

 higher temperatures however, a large excess (10 "/o) of lime caused 

 the solubilitv to diminish, but this is owinu' to the fact that the 

 reaction-equilibrium made its influence felt. 



1) I.e. p. 496. 



31 

 Proceedings Royal Acad. Amsterdam. Vol. XIV, 



