BOGAR. 



713 



Under the second head should especially be 

 mentioned t!u- proei-ss of evaporating the cane 

 jui.v in the partial vanillin seen red by action 

 air-pump within a larire air-t'ght pan and 

 , together of a spheroidal shape, the heat 

 Mug applied to the juice by means of eteam 

 'ating iii ft coil of pipe on the iusido of the 

 pan, or in a steam-jacket about it, or both, so 

 ..ctivo ebullition and rapid concentration 

 secured at temperatures of from 140 to 

 I-'. a heat at which the risk of waste by 

 burning and by transformation to uncrystal- 

 li/.ablo sugar is very small, and at which ac- 

 cordingly a larger percentage and superior 

 quality of suirar are obtained. This apparatus, 

 icuum-pan, with its usual accessories and 

 its management, is, however, too well known 

 to manufacturers generally to require a de- 

 tailed description here. 



The earliest of the improvements properly 

 falling under the third head, was the now near- 

 ly obsolete practice of "claying." The sugar 

 was, as for similar modes at present, filled into 

 inverted conical moulds, in lieu of the coolers, 

 to complete its crystallization and hardening, 

 and then by removal of a plug in the apex of 

 the mould, allowed to drain ; and the latter 

 process was completed by percolation of 

 water from a paste of wet clay spread over the 

 thus displacing and removing coloring 

 and other foreign matters. This process was 

 wasteful, and did not give a clear white nor a 

 hard-drained sugar. Undoubtedly, the so-called 

 " claying " with a paste of sugar, instead of ac- 

 tual clay, has in some cases been resorted to. 

 But, for the raw manufacture, a more effective 

 plan is that of filtering the defecated juice, be- 

 fore evaporation, through " bag filters " of thick 

 cotton cloth, and then through bone-black. The 

 washing of the crystallized sugar after cool- 

 in ir, with alcohol not very dilute, has also been 

 practised. By neither of these methods, how- 

 is a pure and perfectly white sugar ob- 

 tained such result being only possible when 

 the processes proper to the refining of sugar, 

 after its granulatio'n, are employ. -d. 



The principal mechanical modes of purifying 

 and whitening raw sugars, in the moulds, or in, 

 bulk, are the following: 1. In the so-called 

 u pneumatic process," a vacuum is created in a 

 vacuum-client beneath the moulds, and with 

 which, otherwise tight, the mouths of the 

 moulds communicate through partitions of 

 wirc-ganzo, so that the atmospheric pr< 

 from without comes ^nto play to force out from 

 among the crystals the molasses and soluble 

 matters. This process operates best when the 

 crystals are large and linn. 2. The purifying 

 of raw sugars by centrifugal action, a method 

 originating in connection with the beet-sugar 

 manufacture in Europe, but which has been 

 during the last few years extending to the 

 preparation of raw cane sugars, can, where suf- 

 ficient motive power is at hand, be resorted to 

 with advantage. The paste of crystallized su- 

 gar and syrup is run within the inner one of 



two rims of a centrifugal wheel or cylinder, in 

 some forms termed a "hydro-extractor " cs- 

 s -utially, a perforated plate or wire-gauze web, 

 within an outer tight casing to catch ',! 

 p.-!l.-d syrup, and from which latter it is dis- 

 charged by a pipe; the double cylinder, first 

 brought to a velocity of twelve hundred to fif- 

 teen hundred revolutions a minute, is then 

 charged from a reservoir above; and, in from 

 five to fifteen minutes, according to the quality 

 of the sugar acted on. the soluble matters being 

 mainly thrown out, the machine is found to re- 

 tain the crystals in form of a more or less white 

 soft sugar. 



1 'at cuts were granted in this country, in the 

 year 1859, to Messrs. Nicolas and Champagne, 

 for the bleaching and defecation of sugar-juices 

 by the combined use of sulphur and lime; to 

 Mr. K. A. Stewart, for the defecation of cane- 

 juice by means of sulphurous acid gas dissent* 

 inated through it ; and to the heirs of Mr. R. B. 

 Brashear, for a method of defecating by expos- 

 ing the juice in a diffused state to the action of 

 the gas just named, as directly evolved in the 

 fumes of burning sulphur all the parties named 

 hrin :r of the State of Louisiana. In 18G2, Mr. 

 Kdward Beanes, of London, patented in this 

 country the employment of phosphate of am- 

 monia, in conjunction with sulphurous acid or 

 any of the sulphites, in the manufacture and re- 

 fining of sugar; and also the use of liquid am- 

 monia, in lieu of milk of lime, for neutralizing 

 the acid developed in the process (it is stated) 

 of refining sugar, though possibly, also, having 

 reference to the raw manufacture. It should 

 here be added, that sulphurous acid and the 

 sulphites are often employed with a view, di- 

 rectly or incidental!} 7 , to their power of prevent- 

 ing or arresting fermentation in a saccharine 

 juice; while against the sulphites at least the 

 objection has been urged that they tend to pro- 

 duce a soft and imperfect grain in the sugar. 

 In 18C3, Messrs. E. T. and E. O. De Gemini, of 

 Paris, France, patented hero their method of 

 clarifying saccharine juices by subjecting them 

 simultaneously to molecular agitation (by means 

 of a vertical shaft and dashers within the con- 

 taining vat, or of throwing in beneath jets of 

 steam, or of both), and to a treatment with 

 animal charcoal and fuller's earth. 



At least twenty-four different patents are re- 

 corded as granted in the United States in the 

 year 18r.2, for forms of apparatus having for 

 their sole or principal purpose the evaporation 

 and concentration of saccharine liquids; and in 

 the following year, twenty-two patents for ap- 

 paratus having a similar object. The greater 

 number of these, however, are evidently such as 

 have been especially devised with a view to the 

 successful and economical working of the juices 

 of the sorgho and imphef, which, besides being 

 usually concentrated in smaller quantities than 

 the cane juice, require in some other respects, 

 also, a peculiar treatment. (See SORGHUM.) Mr. 

 S. lloyt, of New York, secured in 18G8 a patent 

 for a series of evaporating pans, placed verti- 



