cvi INTRODUCTION. 



weight of boiling water, and when the lime is entirely slacked, passing it over a metallic &quot;sieve, 

 which arrests the grains of sand and the now decarbonated portions. The juice is first heated to 167 

 in the desiccating boiler, the milk of lime is then added, and the whole is stirred to render the mixture 

 homogeneous; the temperature is raised to 212, the supply of steam being cut off when ebullition 

 commences. The lime combines with the free acids, the albuminous substan^s. the fatty and coloring 

 matters, producing insoluble compounds, effecting at the same time a kind of clarification by carrying 

 down with the insoluble compounds organic remains which were suspended in the juice. A thick scum 

 having formed on the surface of the liquid, the latter is kept from boiling in order to prevent its rup 

 ture by the bubbles of steam. The proportion of lime added varies with the nature of the beet, and 

 with their freshness, only three pounds for one thousand pints of juice being used in the beginning of 

 the season, and with fresh beets, which quantity is gradually increased, and frequently reaches ten 

 pounds before the close of the season. An excess of lime remains in the liquor, and forms a deli 

 quescent compound with a portion of the sugar. In some factories it has been endeavored to saturate 

 it with a proper quantity of acid. 



When the operation is terminated, the liquor is drawn off and filtered through animal charcoal ; 

 the filters used for this purpose being large sheet-iron cylinders, having a false bottom pierced with 

 holes like a colander. A cloth is extended over the bottom, over which is spread very coarsely pow 

 dered animal chalk, added in successive layers until it fills the cylinders to within one and a half foot 

 of the top, when another cloth is laid upon it, and is covered by another metallic plate pierced with 

 holes ; each filter receiving from 6,000 to 8,000 pounds of charcoal. The filters should be kept con 

 stantly filled with fluid, which is easily done by means of a stop-cock. After this process, by which 

 the juice loses a portion of its coloring matter, and the lime in excess, which adheres to the charcoal, it 

 is conveyed as rapidly as possible into the concentrating boilers, which are generally shallow, and are 

 heated by a circulation of a light pressure of steam through copper tubes arranged over their bottoms. 

 The juice is raised to a temperature of 70 in 10 or 12 minutes. The workman judges by indications 

 understood by experience, if it is properly concentrated, or if the boiling is completed. During the 

 ebullition, which terminates at a temperature of 2G6 to 275, a considerable portion of the sugar is 

 altered, and to diminish the loss the evaporation must be effected as rapidly as possible. This opera 

 tion has been greatly improved by boiling in vacuo that is, in close boilers, heated by steam, and 

 brought into communication with worms and receivers, in which a vacuum is made. When ebullition 

 takes place at a lower temperature, the quantity of sugar changed is much smaller. 



When the sirup is properly boiled, it is collected in a cooler, which generally receives the products 

 of five or six boilings, and its temperature then falls to about 176. Crystallization then commences; 

 but as soon as any crystals form, they are detached from the sides and the sirup stirred to bring them 

 again into suspension. When the temperature has fallen to 130 or 122 the sirup is poured into 

 large conical moulds of metal or baked clay, resting on the point, which is furnished with a hole pre 

 viously stopped with a plug of wet muslin. The moulds are ranged on long benches with openings, 

 through which the escaping fluids tall into zinc gutters, whence they flow into reservoirs. The tem 

 perature of the room containing the moulds should be about 86. Crystallization is completed in about 

 24 or 3G hours, when the plug is removed from the opening in the mould, and the point of the loaf 

 pierced with an awl so as to draw off the molasses, which is again concentrated even further than the 

 original sirup, and crystallized in moulds. When the molasses is too highly colored, as happens 

 sometimes, it is diluted with a sufficient quantity of water, filtered through animal chalk, concentrated, 

 and recrystallized. The sirup which drains from the second sugar is frequently subjected to the same 

 process for a third time, but the crystallization then requires a great length of time. 



When the sugar has drained sufficiently, the loaves are loosened that is, the moulds are inverted 

 and the loaves detached by gentle blows ; after which they are placed in the wareroom, protected from 

 dampness. This is raw beet sugar, which requires refining before being fitted tor consumption. 



