THE ACTION OF HEAT, ALKALIES AND ACIDS 



267 



Lime added as CaO 

 grams per 100 c.c. 



o 



0-013 



0-026 



0-039 



o- 052 



0-066 



0-079 



0-092 



Acidity of juice 

 c.c. normal acid 

 per 100 c.c. 

 3 . 2 



2-7 



2- 2 



1-8 

 1-4 

 0-9 



Grams lime as CaO 



in solution per 



100 c.c. 



0-045 



0-050 



0-066 



0-078 



0-078 



0-084 



O-IOO 

 O- 112 



Experiments by Cross 35 gave the results tabulated below. In these 

 experiments neutrality refers to the indication afforded by litmus. 



Juice limed to acidity 



of c.c. normal per 



100 c.c. 



No lime. 



Grams lime in 

 solution per 

 100 c.c. 

 0-065 

 0-080 

 0-085 

 0-087 

 0-094 

 o- 115 

 O- Ily 

 0-096 



o- 106 



0-128 

 0-136 

 0-148 

 0-179 

 0-189 

 0-214 



Hence as the quantity of lime used in defecation increases, so does the 

 quantity of lime salts in solution. It was also demonstrated by Cross that the 

 action of sodium carbonate of phosphates in removing the lime salts is very 

 small. 



The Rise in Purity of Cane Juices due to the Combined Action of Heat and 

 Lime. A rise in purity in a cane juice can only be obtained by the removal 

 of non-sugar from solution. Removal of suspended solids does not mean 

 a rise in purity. In the experiment quoted above, the juice contained 

 l6'O per cent, of gravity solids, and polarized 13 '12, being of polarization 

 gravity purity 82-00. With the addition of 0-052 grams of lime, the 

 gravity solids become 16 048, and the precipitate being 0-310 gram there are 

 left in solution 15 738 gravity solids. The polarization gravity purity must 

 now be 83 26. For other quantities of lime the calculated purity will be : 



Lime added grams 

 per 100 c.c. of juice, 

 o 



0-013 

 0-026 

 0-039 

 0-052 

 0-065 

 0-079 

 0-092 



Polarization gravity 



purity. 



82-00 



83-25 



83-25 



83-35 

 83-41 



83-47 

 83-57 

 83-69 



The weight of the material removed by filtration alone was determined for 

 this juice, with the result that the purity of the filtered juice was found to be 



* Alkaline 



