Experiments on the Preparation of Sugar. s®7 



2nd a great quantity of impure matter had been thrown up 

 as fcum. I again fuffered it to cool, drained it through 

 flannel, and, being infpilTated, I obtained eight pounds of 

 fyrup. 



A part of tiiis fyrup I poured into a deep evaporating dift, 

 into which I put fonie glafs rodii, and at the end of two 

 ii\ontha obtained, adhering to the rods, real fugar, fimilar to 

 brown fugar candy. As this fyrup was much more pleafarrt 

 than common fvrup, and exceedingly cheap, it might be ufed 

 as a fubftitute for fugar, like that procured from the white 

 beet. 



In continuing my experiments on the beet, I endeavoured 

 to afcertain the a(i:l:ual quantity of fugar that might be pro- 

 cured from a determined quantity of tb.em. With that view 

 I weighed three pounds twelve ounces of fyrup obtained by 

 the fecond experiment, poured it into a conical veflel of 

 tinned copper, and expofed it to (low evaporation at the 

 temperature of from 65^ to 70° of Reaumur. In the courfe 

 of eight hours there was formed on the furface a cryftalline 

 cruft of granulated fugar, which at the end of twenty-four 

 hours was nearly four lines in thicknefs : having forced it 

 down to the bottom of the fyrup, in two days a new cruft 

 was formed, which was alfo forced down j and this opera- 

 tion I continued till a tough uncryftallifed pellicle only ap- 

 peared on "the remainder of the fvrup :. this induced me to 

 conclude that all the cryftallitable fugar was now feparated 

 from the liquid, which was fliown alfo by its being lels fweet 

 and more (limy. I now put all the cryftallifed fugar, toge- 

 ther with the fluid fyrup, into a fmall lugar mould, which I 

 kept for eight days at the temperature of 30^ of Reaumur, by 

 which means the fyrup' was entirely drained oft', and the 

 fugar remained almoft in a dry ftate. The whole of this ope- 

 ration employed thirty-fix days. Tlic raw fugar I obtained 

 was flill a little moift in the iufide, but it did not dcliquefce 

 in the courfe of three week?, during which I kept it in an 

 open vcfl'el, and il weighed two pounds eight ounces: the 

 fyrup which drained from it weighed forty-eight ounces; 

 confcqilcntly, from the three pounds twehc ounces of fyrap 

 employed, twenty ounces of aqueous parlitles had cvapo- 

 7 rated. 



