SUGAR. 



179 



sugars together, it appears that the Aba factory makes but 33 per 

 cent. ; Bene Mazar, 55 per cent. ; the Australian mills, 41 per cent, 

 and 48 per cent, respectively; and the Colonial Company, 47 per 

 cent. This seems to demonstrate that the sulphurous acid gas pro- 

 cess, when combined with rapid concentration, realises a larger per- 

 centage of marketable sugar than any other system of manufacture ; 

 and this result will become still more apparent by an inspection of 

 the following table of produce by different mills, from which it will 

 be seen that the Aba factory also yields the highest percentage of first 

 white sugar : 





Egypt. 



W. Indies. 



New South Wales. 





Aba. 



Bene 

 Mazar. 



Colonial 

 Company. 



Chats- 

 worth. 



South- 

 gate. 



„ „ yellow 



Molasses and third sugar 



56-1 



18-7 

 25-2 



43-6 



20*8 

 35-6 



43-6 



23*6 

 32-8 



50 -8 

 16-5 

 32-7 



62 '5 

 8-4 

 29-1 





100- 



100- 



ICQ- 



100- 



100- 



Percentage of molasses on first | 

 and second sugars . . , . / 



33-7 



55-3 



47-6 



48-6 



41-4 



" The total yield of all sugars and molasses, in pounds per gallon, 

 was 1-825 at Aba ; 1*62 and 1*75 in the Australian factories ; and 

 2'19 in Demerara, showing that my statement about the bad condition 

 of the Egyptian canes is fully borne out. The specific gravity of 

 cane juice is affected not only by the saccharine matter it contains, 

 but also by the various impurities in solution, and even by solid 

 matters in suspension. The density of juice is generally taken by 

 Beaume's hydrometer ; and as an illustration of the manner in which 

 suspended matter affects its indications, it may be mentioned that 

 milk of lime at 70° temperature, as long as it is kept agitated, will 

 indicate 10° Beaume when mixed in the proportion of ten parts by 

 weight of water to one part of lime, but, when suffered to subside, 

 will register only 2° in the clear solution containing one part of lime 

 in 700 parts of water. Throughout my experiments the density of the 

 juice and syrups was carefully ascertained, and I found, on comparing 

 the actual yield of sugar with the tabular quantities represented 

 by the density of the juice, that there was a total loss of 5*91 per 

 cent. ; and between the quantity contained in the juice entering the 

 concentrators, and that held by the syrups running out, a loss of 1*62 

 per cent. These results, though valuable as indicating that no great 

 error had been committed in the numerous measurements, cannot be 

 taken as strictly true, because the readings of the hydrometers were 

 imdoubtedly affected by the lime, and its sulphate was proved to have 

 been held in solution by the deposits both in the concentrators and in 

 the vacuum pans. 



"The information obtainable as to the manner in which the den- 



N 2 



