ON THE TNYEESTON OF CANE SUGAR. / 



The optical rotation of the sugar soUition, not inverted, 

 corresponding to the mean dihite solution was : 



(9) 12.682°, (10) 12.669°; mean: 12.675° 



Thus the degree of the inversion in the original solution in 

 percentage is as follows : 



12.675 + 4.140 ^^^^ _„_ 

 12.675 + 4.176 ^^^^^ = ^^'^- 



V. The reverse reaction was next studied. The experiments 

 were carried out as follows : 



About 20 grams of cane sugar were dissolved in a flask of 

 50 c.c. capacity and hydrochloric acid was added to a concentra- 

 tion of 0.5 normal, when the solution was diluted to 50 c.c. 



When the inversion was complete, about 5 c.c. of the solution 

 were taken out into a weighed flask of 25 c.c. capacity and 

 weighed. After the addition of sodium acetate, it was diluted 

 to 25 c.c. and polarised. 



About 5 c.c. of the same original solution were taken out 

 into a weighed flask of 25 c.c. capacity and weighed. Air was 

 passed over its surface by means of a powerful water pump and 

 when the volume of the solution was reduced to about one-half, 

 the flask was weighed again. Sodium acetate was then added, 

 diluted to the mark and polarised. 



