332 DATE SUGAR INDUSTRY IN BENGAL. 



Invert sugar. For this the method of Brown, Morris and 

 Miller was followed at Pusa. 1 The Cu 2 was estimated, however, 

 by solution in a sulphuric acid solution of ferric sulphate. An 

 amount of iron is reduced corresponding to that of the Cu.>0. 

 The amount of ferric reduction was determined by titration with 

 potassium permanganate whose strength was known in terms of 

 CuO. The percentage of invert sugar was then calculated from 

 the tables in the paper quoted. 



The method was checked by preparing a solution of invert 

 sugar of known strength by inverting pure cane-sugar. The solu- 

 tion, was then diluted to 10 times its bulk and then contained in 

 10 c.c. 0'0975 gm. invert sugar. The invert sugar was then esti- 

 mated in the solution by the method outlined above. Triplicate 

 determinations were made, using 10 c.c. of the dilute sugar 

 solution. 



KMn0 4 used c.c. 



(1) .. .. .. 23-45 



(2) .. .. .. 23-55 



(3) .. .. .. 23-50 



Average . . . . . . 23 '50 



less blank determination 0'55 



22-95 



1 c.c. KMnO 4 was equivalent to 0"01032 gm. CuO. 



.'. 22*95 is .. 0-2368 



By the tables : 



0'2368 gm. CuO equals . . . . "0973 gm. invert sugar, 



actually present . . . . '0975. 



The method has frequently been checked, with equally good 

 results. In camp the reducing sugar was determined by direct 

 titration of the juice after clarification, against the copper solution. 



Total solids. A platinum basin containing cleaned pieces of 

 pumice was brought to a constant weight, 10 c.c. of the juice was 

 then run in and dried to a constant weight. 



Total nitrogen. This was determined by the Kjeldahl method 

 using 25 c.c. of the juice. 



J. C. S, Trans. 1897, page 278, et seq. 



