THE CLARIFICATION OR DEFECATION OF THE JUICE. 



hydrosulphite required to obtain the maximum bleaching effect found by the 

 writer was one pound per ton of sugar, but the quantity necessary has to be 

 determined by trial and error, and a much less quantity is stated to be required 

 by the makers of this compound. 



Hydrosulphite has no effect on the dark coloured products obtained on 

 overheating sugar juices, and the specific effect claimed for it in reducing 

 viscosity hardly seems possible when the small quantity used is borne 

 in mind. 



The Colour Reactions of Cane Juice. The colour reactions 

 of cane juice having an important bearing on the manufacture of direct con- 

 sumption sugar may be mentioned here. In the presence of an excess of 

 alkali, filtered cane juice is of a golden yellow colour; if the alkali be 

 gradually neutralized with an acid a point is reached where the golden yellow 

 colour turns to an olive brown; the addition of the acid being continued, the 

 cane juice finally becomes almost colourless. When in the intermediate olive 

 brown zone, the juice is almost exactly neutral. The colour reactions of cane 

 juice as described above are exemplified in the following experiment : 



To 100 c.c. of clarified almost neutral cane juice, exactly sufficient normal 

 caustic soda was added to develop the golden yellow tint, the quantity found 

 necessary to be added being 1 c.c. To 1 00 c.c. of the cane juice thus treated 

 normal sulphuric acid was added and the changes in colour observed ; the 

 different juices were kept at a temperature of 95 C. for half-an-hour, so as to 

 determine at what point appreciable inversion (see below) set in. The details 

 of an experiment are given below. 



100 c.c. of clarified cane juice treated with 1 c.c. normal caustic soda 

 developed maximum yellow colouration. 



c.c. normal acid Polarization after 



added per 100 c.c. Colour. Reaction. heating to 95 C, 



of prepared juice. for half-an-hour. 



Golden Yellow Alkaline 58-1 



4 ... .... .... 58-0 



8 .... .... 58-1 



9 j ... ( Intermediate Neutral 58 '0 



1-2 J .... I Olive brown zone ... ,, 58*0 



1-4 .... Light .... Acid 58'1 



2-0 .... ,, ..... ,, 58-0 



2-2 .... ,, 57-0 



2-6 .... .... .... 49-0 



It was not until there was an excess of normal sulphuric acid of 1 c.c. 

 per 100 c.c. of juice over and above the neutral intermediate zone that 

 inversion was detected. 



In Sugar and the Sugar Cane the author expressed himself thus : " This 

 is thus the limit which the manufacturer can allow himself when making 



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