1816.] French Instilule. 



come heated, or decayed, or grerminatcs, 

 tlie heap must be opened, the injured 

 loots separated from it, and then made 

 up again. 



Oh the Extraction of Sngnr. — ^Tiie 

 most economical mode of washing is to 

 put from 100 to 1401bs. into a cylinder 

 composed of thick iron wire, half tlie 

 cylinder being immersed iii water con- 

 tained in a trough under it; the cylinder 

 is kept constantly turning round. In a 

 little time the beet is freed from the 

 dirt, tlie cylinder is then raised above 

 the trough, a door which it contains is 

 opened, and the beet slides down an in- 

 clined plane, which carries it beyond the 

 trough. 



I have no washing in my establish- 

 ment; but I have the top and radicles 

 cut off, and the surface of the roots, 

 cleaned, all with a knife. This opera- 

 tion is executed with facility by women, 

 and costs twelve sous, or sixty centimes 

 per thousand. 



The sugar is extracted by two succes- 

 sive operations. 1st. The beet is re- 

 duced to a pulp by means of graters: the 

 best of these graters consist of cylinders, 

 furnished on the surface with indented 

 plates; these cylinders may be moved so 

 rapidly, by means of wheels, that they 

 will make 400 revolutions in a minute, 

 and will tear and reduce the beet to a 

 pulp in an instant. Two of these gra- 

 ters, put in motion by the same ma- 

 chinery, and altcnded by three women 

 and two children are sufficient to grate 

 daily 10,000 weight of beet, by working 

 only lliur hours a day, two hours at a 

 time; it is very rare that I'.aif an houj 

 more is necessary. "^ 



In order that the pulp may be of a 

 good quality it must have the appear- 

 ance of a soft paste, witiiont any lumps ; 

 for the press, however powerful, can ex- 

 tract hut a very small proportion of juice 

 from fragments of beet that have not 

 been torn. When it is only crtished be- 

 tween inill-stones, in the manner that is 

 practised for making cider and perry, 

 the juice obtained from the press is not 

 more than 30 or 40 per cent, whereas, 

 when it is torn by the graters, from 65 

 to 7.0 per cent, is extracted. 2dly, As 

 fast as the pulp is formed it is submitted 

 to pressure, in order to extract the juice. 

 I begin by putting it into small lever 

 presses at fn st, and afterwards removing 

 it to others more powerful, so as to ex- 

 tract from t)5 to Taper cent, of juice. 

 'J'lie operation is perfect when the marc 

 tir di'cgs ure so dry, tiiat on squeezing 



53 



it hard with tlie hands it docs not wet 

 them. To diminish tiie expense of ma- 

 nual la])our, 1 place t!ic graters and 

 presses on a stage, in such a manner 

 that the juice falls of itself, through 

 leaden canals, into tiie boilers, which 

 are placed on the ground. It is neces- 

 sary that the pulp should be expressed 

 as fast as it forms, or else it blackens, 

 and a degree of fermentation com- 

 mences, which renders the extraction 

 of the sugar more difficult. The juice 

 marks from five to eleven degrees, and 

 conmicnly fiora seven to eight, by 

 Beaimie's areometer, 



I have before mentioned, that tlio 

 juices run immediately out of the presses 

 into a boiler, which 1 call a depuratur, 

 in relation to its use. Supposing two 

 operations to be efleeted in a dav, and 

 that 5000 weight of beet-root is" ope- 

 rated upon each time, this boiler, which 

 is round, should be five feet aiul a half 

 wide, and three feet eight inches deep ; 

 of these dimensions it will contain the 

 whole product of one operation. As 

 soon as the boiler is one-third, or half 

 full, the fire is lighted. By the lime 

 that the juice has ceased running from 

 the presses, it will already have acquired 

 from forty to fifty degrees of heat, which 

 is sufi'ered to increase to sixty-five or 

 sixty-six degrees; and the moment it 

 has attained this heat, the fire is smo- 

 thered by covering it with wet coals. 

 Liinc, slaked with warm water, is then 

 thrown into the boiler, in the proportion 

 of tM'o grammes and a half (about forty- 

 eight grains) to a litre of juice, beino- 

 careful to vary the proportion aecordin"- 

 to the consistence of the juice. The 

 liquid mass must be well stirred, in all 

 directions, for some minutes, and then 

 the fiic is revived, in order to raise the 

 heat to eighty degrees ; that is, to the 

 degree nearest approaching to ebullition. 

 The fire is then taken out of the fire- 

 place, and as the liquor cools a coat 

 forms on its snrlace, which in half an 

 hour has accpiircd a degree of consis- 

 tence; which, at the end of three-quar- 

 ters of an honr, is carefully taken otf 

 w if h the skim. As soon as it is skimmed, 

 a cock is tinned, which is fixed about a 

 foot frcmi the bottom of the boiler, and 

 the liquor runs out into a square boiler ; 

 afterwards a second cock is opened, 

 which is quite at the bottom of the' 

 boiler, in order to empty it entirely, and 

 the liquor is made to fall nj)on a filter, 

 through which it also runs into the 

 sqiiuru boiler. 



Th« 



