OTHER. AGENTS IX DEFECATION. 297 



pounds of juice in each experiment, and different quantities of "svater 

 vere added, according to the density of the juice operated upon, vary- 

 ing fi'om 10 to 35 per cent of the weight of the juice. In each case, 

 the actual amount of sucrose and glucose present in the juice, and in 

 the syrup obtained from the juice, Avas determined, and it was found, 

 as an average of the fourteen experiments, that 90.4 per cent of the 

 sucrose, and 88.0 per cent »^if the glucose, in the juices was recovered 

 in the syrup — an amount of iocs easily accounted for as indispensable 

 in the necessary operations of manufacture. 



Action of Lime upon the Glucose and Sucrose in Juices during Evajxiration. 



The f )llowing experiments were made, for the purpose of determin- 

 ing the effect of lime upon the sucrose and glucose in juices during 

 evaporation, and will be studied with much interest by the sugar 

 maker, as the results are, in some respects, surprising and of very great 

 practical importance. 



In the three sets of experiments, the results of which are given be- 

 low, a solution of the strength given, equal in volume to 2,000 c. c, 

 was placed in a large glass flask, and boiled in the open air over a gas 

 stove for several hours. 



Samples were taken at firs*^, and at intervals during the process of 

 boiling, and subjected to analysis. These samples were always taken 

 just after the evaporated water had been replaced. The amount evap- 

 orated was determined by graduations upon the side of the flask ; but, 

 on account of the width of the column of liquid, it was difficult al- 

 ways to bring the solution back to the exact yolume of the original, 

 and, doubtless, some of the irregularities recorded below are due to 

 this cause. 



In each sample taken for analysis, the acidity or alkalinity, glucose 

 and sucrose, were determined, the sugars being estimated by the same 

 methods used in the analysis of juices. 



In the series of experiments Xo. 1 , no color appeared until sample 

 Xo. 5 was taken, at the end of four and a half hours' boiling: the so- 

 lution then became gradually darker, until sample Xo. 8 Avas taken, 

 which was very much darker than sample Xo. 7. 



Xo. 9 was still much darker, and then the coloration proceeded grad- 

 ually until the end, sample Xo. 11 being of a sherry-wine color. 



In the series of experiments Xo. 2, there was a gradual darkeninsc 

 of color till the end, sample Xo. 24 in this series resembling a dark 

 whisky in color. 



In the series Xo. 3, sample Xo. 1 was colorless; Xo. 2 was dark- 

 brown, with a heavy precipitate. The color gradually darkened to the 

 end. Sample Xo. 12 was a very dark-red wine color. 



