SUGAR. 



715 



trating at low temperatures in the vacuum-pan, 

 ami llio treatment uf the loaves with a pure 



instead of day. In truth, tin : 



which precisely 



i.-thods ami course aro pursued ; and 



; .;.-(, in many of tliein, there, are certain 



apparatus and modes of treatment 



proprietors may prefer nut to disclose. 



forms which the refiner aims to produce 



is 1, loaf augur, and tln-n (in 



this country now more in demand), the dcriva- 



i'rom it ; namely, l>, Mork, or cut-loaf; 8, 



/. or inin/> ; 4, granulated; and 5, pul- 

 ri/r ]>'>/r,l, m/Migar, of different fincn 

 and besides tlieso, C, crystals (larger than tho 

 ordinary grain), and 7, the softer coffee sugars. 

 Superior sorts of raw sugar aro properly re- 

 1 for all but tho last named, which aro 

 od from lower grades of raw sugar, either 

 alone, or mixed with the drainings of the loaf 

 and crystals. The refiners of this country and 

 (Jreat 1 5 ri tain taken together, employ raw su- 

 gars of great variety West India, Louisiana, 

 South American (Guiana, Brazil, Chili, etc.), 

 Mauritius, Java, and Manila cane sugars; mo- 

 lado; Hindostan and Indian date sugar; and 

 finally, beet sugar, to somo extent. 



In refining, raw sugar is first mechanically 

 mixed with water in a tank, and then brought 

 into complete solution within large copper dis- 

 solving pans, known as " blow-up cisterns," in 

 water at 165 F., and by aid of steam, the li- 

 quor b'eing brought to 29 B. (sp. gr., 1.250). 

 Bullock's blood may be added at this stage for 

 clarifying, and with or without some fine ani- 

 mal charcoal; or the mixture of gelatinous alu- 

 mina arid silica known as " finings " may be 

 employed. In any case, lime-water or some 

 equivalent is added to correct acidity : the liquor 

 may finally bo skimmed, but it is at all events 

 strained through the false perforated bottom of 

 the dissolving pan. The solution may next bo 

 filtered through '' bag filters;" and these being, 

 when too much fouled, washed by mechanism, 

 the impure saccharine liquor obtained may be 

 olarilied, and the sugar in it saved by employing 

 the liquid to dissolve fresh quantities of raw 

 sugar. In any case, the removal of the coloring 

 i natters, albumen, lime, etc., of tho solution is 

 completed by filtering through crushed or gran- 

 ulated bone-black, contained in large, upr'ght 

 cylinders. From these, the liquor issues for a 

 time in a nearly or quite colorless condition, 

 though it gradually begins to show color, until, 

 in course of from 24 to 72 hours, the black will 

 BO far have lost its decolorizing power as to 

 require to bo subjected to the process of revivi- 

 fication. (See BONE-BLACK, etc.) 



Certain methods of conducting the hone-black 

 filtering, which aro more or les^ peculiar, are 

 in use. Mr. William Mollor, of New York, em- 



Sloys a system of filt.-riiiL' in which, the cylin- 

 ors being properly connected in sets of three, 

 and furnished with air-tight covers, the course 

 of the solution in each set is, downward through 

 the first cylinder, upward through the second, 



and downward again through the third; steam 

 being admiit-d >, ,-r tho solution in the first 

 cylinder, when charged, and in such quantity 

 and so long as required to throw the solution 

 by pressure to tho top of tho second cylinder, 

 after which it of course descends through tho 

 third. The solution is believed to be, in this plan, 

 able to make for itself particular channels 

 through the charcoal, thus to some extent 

 escaping tho action of tho latter; and tho de- 

 colorization is said to bo more thorough than 

 in ordinary methods of filtering downward 

 only. The Bertrand system of filtering is also 

 to somo extent introduced in this country, as 

 at tho refinery of Messrs. Havemeyers and 

 Elder, Brooklyn (E. D.), N. Y. In this also 

 the filters are connected in sets of tJiree, and 

 very ingeniously by means of the requisite num- 

 ber of pipes, in such a way that every day two 

 of the cylinders shall be in use in filtering suc- 

 cessively the same solution, while at the same 

 time the third cylinder (the one which had just 

 before been the longest in use, and so taken in 

 order through the set, day after day,) shall bo 

 disconnected from the others, to be washed 

 through, and to have its charcoal removed and 

 revivified. The requisite pressure for raising 

 the solution from below the first to the top of 

 the second filter, and for aiding the filtration, 

 is secured by simply placing tho charging reser- 

 voir on a floor above. 



Tho filterol solution is next run through a 

 " measure cistern " in successive charges into 

 the vacuum-pan, the charges being made larger 

 and fewer, the finer the grain desired. Tho 

 boiling may bo commenced at 180 or 170 F., 

 and be lowered as the syrup becomes more 

 dense to 145, the latter, when fit to granulate, 

 being discharged into another pan, tho ' heater," 

 and in this heated by steam for a time to 180, 

 and meanwhile stirred, to favor the formation 

 of a hard grain : or tho concentration may bo- 

 gin at 160, raising the heat toward tho close to 

 180, and transferring tho syrup when ready to 

 crystallize at once into coolers or granulaton. 

 The fitness of the syrup to crystallize is ascer- 

 tained by the simple means of examining a 

 drop of it against the light, by drawing out be- 

 tween the thumb and finger tho ingenious 

 device known as tho "proof-stick," enabling 

 tho sugar-boiler to withdraw for this purpose a 

 little of the syrup from tho pan, without admis- 

 sion of air into the latter. 



The concentrated syrap, being allowed to 

 cool and further to solidify, is finally filled into 

 moulds, of different sizes, to drain; and as, 

 however good the material used or careful tho 

 preparation, the sugar coming out of the vac- 

 uum-pan will show more or less color, to re- 

 move this the process of u liquoring " is now 

 ally resorted to: a pure, white, saturated 

 syrup is several times poured in upon tho 

 loaves, this by its water displacing the coloring 

 impurities, and, while it can dissolve no sugar, 

 serving to give a final coating of sugar to tho 

 crystals. After thus draining for several days. 



