RAW SUGAR 431 



in that it assumes the crystals are pure sugar. In every case some adsorption 

 of non-sugar occurs, and this adsorption is greater as the purity of the mother 

 liquor falls. In certain cases the presence of non-sugar may modify the 

 shape of the crystal, and in some cases at least with sodium chloride a 

 definite molecular compound of sugar and salt crystallizes. 



The conclusions to be drawn from the above argument may be modified 

 in two ways in actual practice. The manufacturer may dry his sugar after 

 it leaves the centrifugals ; such an operation, while appreciably raising the 

 polarization and diminishing the water content, will leave the value of the 

 other constituents appreciably unaltered within the limits of the ordinary 

 analysis. In the second case the adhering molasses may be removed in 

 whole or in part by washing with water, whereby raw sugars of high polariza- 

 tion may be obtained from low purity massecuites. Such sugars can be 

 obtained with a very low water content owing to the dilution of the molasses 

 and consequent decrease in the viscosity. 



Finally, as regards the sugar on its arrival at port of destination, further 

 disturbance, due to the action of micro-organisms, may have occurred 

 through inversion of sugar, and the destruction of inverted sugar thus 

 formed and of that originally present. 



The non-sugar present in raw sugars is derived principally from the non- 

 sugar in the juice and its composition is modified by the manufacturing 

 process under the following heads : i. Phosphates and albuminoids are 

 precipitated. 2. Non-sugars are added, as lime and occasionally as sul- 

 phurous acid and phosphoric acid. 3. Sugar may be caramelized or inverted 

 nto reducing sugars, and reducing sugars may be broken down by the action 

 of heat and lime appearing as organic lime salts. 4. Mineral matter may 

 be precipitated as scale on concentration. 5. On storage reducing sugars 

 may be both formed from cane sugar, and reducing sugars thus formed and 

 those originally present may be destroyed by the action of micro-organisms. 

 It is customary in analysis to report reducing sugars, ash, and organic non- 

 sugar, the last-named as obtained by difference. Owing to the variation 

 in the amounts of these substances originally present and to the alterations 

 in manufacture, it is impossible to give any definite composition for the 

 non-sugar, but it will be found that in the great majority of cases the ash is 

 present in less than half the quantity of either the reducing sugars or organic 

 non-sugar, and that these are present in quantities of the same order. 



A typical 96 test made from a 75 purity massecuite not washed or 

 subsequently dried will contain from 0-4 to 0-7 per cent, ash and from 

 i to 1-5 per cent, of both reducing sugars and organic non-sugar. Taking 

 this sugar as typical, the composition of sugars obtained from massecuites of 

 higher and lower purity and of washed sugars can be calculated. 



The following generalities are, however, allowable : 



1. Sugars made from heavily fertilized canes will contain a larger pro- 

 portion of ash. 



2. Sugars made from exceptionally ripe and pure canes will contain a 

 small proportion of reducing sugars. 



Both the influences mentioned above are to be observed in Hawaiian 

 sugars. 



3. In sugars made from low grade material, especially from massecuites 

 boiled blank and cooled at rest, the proportion of reducing sugars tends to 

 increase, due to an increase in the reducing sugars following on inversion of 

 cane sugar. 



