310 EXPERIMENT STATION RECORD. 



or in alkaline solutions. The action of tlie neutral salts of tlie alkaline earths 

 is much greater than is that of the neutral salts of the alkalis. At high temper- 

 atures sulphates of the all^alis and alkaline earths, which at lower temperatures 

 retard the rate of Inversion, invert cane sugar. Neutral salts of weaker acids 

 act similarly to alkalis and retard inversion at high temperatures. The dominant 

 factor in determining the rate of inversion at temperatures above 100° is the 

 amount of free alkali. The inversion caused by varying quantities of neutral 

 salt is proportional to the amount of suit present. Wilhelmy's law of mass 

 action does not hold as regards quantity of sugar inverted in unit time, but 

 the rate of inversion increases with the time aud is about 30 times as great 

 for a 30-minute period as for a 5-minute period. 



" The system obtaining in cane juices is a very complex one, consisting of 

 very variable amounts of salts of both strong and weak acids and of free alkali. 

 Hence a temperature which may be safe with one juice may cause serious in- 

 version in another. With the conditions usually prevailing in local factories, 

 juices should suffer a half hour's heating at 120° with no detectable loss of 

 sugar. It would be conservative to adopt this temperature as the highest to 

 which cane juices should be subjected during the process of evaporation, though 

 under a careful system of control and observation a tempei'ature of 125° (or 

 even 130° for shorter periods) might be i)ermissible. 



" In the presence of neutral salts of strong acids at high temperatures the 

 isomerization of dextrose is small. It is larger with sulphates of the alkalis 

 and larger still with the alkali salts of weak acids. In the presence of alkalis 

 at high temperatures dextrose is isomerized into a mixture of dextrose and 

 levulose. Simultaneously there is a fall in polarization. The dextrose is in 

 excess of the levulose in proiwrtion about 2 : 1 ; a portion of the reducing sugars 

 is desti'oyed as such, the amount destroyed increasing with increase in alkali. 



" When invert sugar is heated [in the presence of neutral salts of strong acids 

 at high temperatures] a portion of the levulose is isomerized to dextrose, the 

 proportion of dextrose to levulose obtaining eventually very similar to what ob- 

 tains when dextrose alone is heated. As with dextrose, a portion of the reduc- 

 ing sugars disappears and the destruction with invert sugar is comparable to 

 the destruction when dextrose alone is heated. Probably in the presence of 

 alkali a fixed equilibrium between dextrose and levulose obtains, the position of 

 equilibrium being rapidly obtained at high temperatures. 



" The sterilization of cane sugar products is possible, since it occurs almost 

 instantaneously at 125°, which is very close to the thermal death point of the 

 most heat resistant sugarhouse bacteria, and since at this temperature in alka- 

 line solution the inversion of cane sugar is very slow. 



" The effect of high temperatures on ' clarification ' is very small ; the most 

 that can be hoped for is a juice from which the dirt might be separated with a 

 little more ease. The dark coloration observed when cane sugar is heated at 

 high temperatures in the presence of alkalis does not indicate a detectable 

 destruction of sugar. The use of high temperature evaporation and the pre- 

 heater system of evaporation, and also the sterilization of all cane sugarhouse 

 products, is possible under a rational system of control." 



Calculation of nonsugars, Demichel (Bui. Assoc. Chim. Sucr. et Distill., 

 27 (1910), No. 12, pp. 1111-1119; ahs. in Amer. Sugar Indus, and Beet Sugar 

 Gaz., 12 {1910), No. 10, p. 368).— ^'i^ formula for the approximate calculation of 

 nonsugars in sugar products is given as follows : N=1.000 (D — D') (G/G — g). 

 In this formula N represents the nonsugar, D the density of the impure product, 

 D' the theoretical density corresponding to the Clerget sugar, g the specifie 

 gravity of water at 15.5° C (equal to 0.0091G) and G the specific gravity of the 



