722 



FARMERS' REGISTER. 



[No. 12 



^Evaporation. 



The next process in the mariufactuie is to dissi- 

 pate the water, which is done by " hoihng away," 

 as it is commonly called, but in technical lan- 

 guage, evaporation. 11" in the process of defeca- 

 tion an excess of iime has been used it should be 

 extracted. This may be done by a mixture of 

 sulphuric acid and water, in the proportion of one 

 of the former to ibrty-ibur of the latter. This 

 mixture, put in contact with the lime, causes an 

 an effervescence, by which the lime is thrown ofi', 

 and the cessation of which is a sure evidence that 

 the lime is neutralized. Some manufacturers say 

 that a small portion of lime should be allowed to 

 remain, and others that the whole should be neu- 

 tralized. As practical men differ on this point, we 

 may safely conclude it is not very material. 



The juice is boiled down till it is reduced to 

 about one-fifth or one-sixth of its original quantity. 

 For this purpose pans or kettles may be used ; but 

 it will be seen that those vessels which present the 

 greatest surface to the fire, and give the least 

 depth to the juice, will best facilitate evaporation. 

 As the water evaporates, flaky substances will 

 separate from the juice and collect in a white foam 

 on the surface, which must be skimmed off as it 

 appears. To promote their separation, the boil- 

 ing is commenced with a moderate fire, which is 

 subsequendy increased as they disappear. Some- 

 times the white of eggs beaten, or a little blood, is 

 added for the same purpose. During the boiling, 

 the juice will rise in froth and flow over the top of 

 the pan, unless prevented by occasionally throw- 

 ing in a small quantity of some fatty substance. 

 Butter is commonly used, but tallow, lard, &c. 

 will answer the same purpose. It not onl}' 

 causes an immediate subsidence, but hastens evap- 

 oration. 



Clarification. 



After being defecated and evaporated, the juice 

 is yet in a degree impure, and the object of the 

 next process is to separate it from its remaining 

 impurities, and hence is called clarification. This 

 consists in filtering it through animal charcoal 

 granulated [burnt bones broken to grains.] and is 

 performed in the fbllov\ing manner. Tubs, or vats 

 in the form of those used for leaching ashes are 

 made of wood or metal, and furnished with a cock 

 inserted near the bottom. The size of the vats is 

 immaterial ; but those of the ibilowing dimensions 

 will be ibund most convenient — 2 feet 8 inches 

 deep — 1 foot 8 inches in diameter at the top, and 

 11 inches at the bottom. They may be four sided 

 or round ; but those made of staves and hooped 

 with iron hoops we should think the cheapest, and 

 on some accounts the best. 



A strainer standing on legs, and covered with 

 coarse cloth, must first be placed in the bottom of 

 the vat and filled with the charcoal — about 100 

 pounds will be necessar}' for a vat of the above 

 dimensions. The charcoal must then be covered 

 with another strainer and cloth, and the vat filled 

 with evaporated juice, or, as it is then called, sirup. 

 After standing long enough to leach through the 

 charcoal, the cock must be turned and the sirup 

 be slowly drawn o(f, and the vat re-filled as last as 

 it is emptied. The charcoal nmst be changed 

 twice a day j but it may be washed and reburnt, 



and, thus prepared, it will answer for another fil- 

 tration. This may be repeated until it is con- 

 sumed. 



Concentration. 



The next process is to solidify the sirup, and 

 hence is called concentration. To accomplish this 

 it must be again evaporated until it is brought into 

 a proper state for crystalizalion. As it is impor- 

 tant that evaporation should cease as soon as it 

 arrives at this point, Chaptal gives the following 

 rules for ascertaining the fact. " 1. Plunge a 

 skimmer into the boiling sirup, and upon with- 

 drawing it, pass the thumb of the right hand over 

 its surface, mould the sirup which adheres to the 

 thumb, between that and the fore-finger, till the 

 temperature be the same as that of the skin — then 

 separate the thumb and finger suddenly — if the 

 boiling be not completed, no thread will be formed 

 between the two ; if there be a filament, die bod- 

 ing is well advanced ; and the process is comple- 

 ted as soon after as the filament breaks short, and 

 the upper part, having the semi-transparency of 

 horn, curls itself into a spiral, 2. The second 

 mode of judging of the completion of the process 

 is by observing the time when the sirup ceases to 

 moisten the sides of the boiler, and then blowing 

 forcibly into a skimmer which has just been im- 

 mersed in it — if bubbles escape throuirh the holes 

 of the skimmer which ascend into the air in the 

 same manner as to soap bubbles do, the liquor is 

 considered to be sufficiently boiled." 



When the concentration arrives at this point, 

 the sirup must be taken from the boiler and poured 

 into large pans, for the purpose of cooling. The 

 pans must be placed in the air, and the sirup occa- 

 sionally stirred during the process of cooling, 

 which wUl be completed in about two hours. On 

 examination, the bottom and sides of the pan will 

 be fiund covered with a thick bed of crystals, 

 having but little consistence ; on the surface of the 

 sirup, a crust will also be formed. To promote 

 crystalizalion, or, as it is more properly called, 

 graining, a thin bed of brown sugar is sometimes 

 put upon the bottom of the cooling pan, in order to 

 make a nucleus about which the crystalized 

 matter may gather. 



After the sirup is cooled and crystaliziid, or 

 grained, all that remains is to separate the sugar 

 li-om the molasses, and it is fit for domestic con- 

 sumption or market. To effect the separation, 

 moulds, as they are called, must be prepared in the 

 form of defecating vats, with the lower end drawn 

 to a point, or so near a point as to leave a hole 

 of three-fi)urths of an inch in diameter. These 

 may be made of wood, metal or earthen ware, 

 and their capacity may be regulated according to 

 the convenience of the nianuliicturer. Those 

 used in the sugar factories in France usually are 

 large enough to contain five or six gallons. They 

 are also used in the refining process. Before using 

 them, if of wood, they nmst be soaked several 

 hours in water, and dried a short time before they 

 are filled with sirup. Thus prepared, and with a 

 cork in the hole at the point, they must be filled, 

 or nearly filled, with crystalized sirup, and .se- 

 cured in an upright position, over a pan or tub of 

 sufficient size to receive the quantity of molasses 

 it contains. Alter standing from 12 to 36 hours, 

 according to circumstances, the cork is withdrawn 



