RAW SUGAR 



439 



Sucrose in sugar of s^ purity s^ {j — m 



Sucrose in sugar of s purity j (s 



m 



j {s — m) _ s^ (s ~ m) 



) '^ s {j ~ m) s (Sj — m)' 



X 



That is to say, the relative quantities of sucrose obtained in raw sugars of 

 different purities depend only on the purity of the sugar and not on the 

 purit\^ of the juice whence they are obtained. 



Now let a definite value be given to m, say, 0-40 as typical of the gravity 

 purity of well-exhausted molasses ; then, if s be put equal to i (i.e., let the 



product be pure sugar) the value of the expression — 



(I 



— gives the 



sucrose in a raw sugar of s^ purity compared with what will be obtained 

 when pure sugar of 100 purity is made. 



In the table below are calculated values of the expression for values of 

 Sj from 0*94 to 0-99. 



Values of 



^1(1 



for m — 40, OR Sucrose in Sugars of 94 to 99 Purity 



The table may also be used to obtain the relative quantity of sucrose 

 in raw sugars of different purit}'. Thus the sucrose contained in a raw sugar 

 of 96-5 purity compared with that in a raw sugar of 97-4 purity is as 

 1-0247 ^ I -0181 = 1-0065. As a commercial basis of comparison, however, 

 it is the actual weight of raw sugar which is required, and to obtain this 

 comparison it is necessary to divide the values given in the above table 

 by the sucrose in the product, pure sugar being taken as i. Thus, in the 

 example given above, if the sugar of 96-5 purit}' contains 95-8 per cent, 

 sucrose, the weight of raw sugar compared with the weight of pure sucrose 

 will be 1-0247 -^ 0-958 = 1-0696, and if the sugar of 97-4 purity contain 

 96-1 per cent, sucrose, its relative weight will be 1-0181 ~ 0-961 = 1-0594. 

 The relative weights of the two raw sugars will be as 1-0696 : 1-0594 = 

 1-0097 : I -0000. 



To complete the argument developed above it may be also shown that 



