SUGAR. 89 



lime.) From this solution the alcohol threw down white flakes, very 

 much resembling those of mucilage separated from water by the same 

 liquid. A little sugar was dissolved in alcohol, and phosphuret of 

 lime added to it. No apparent action took place. The mixture, 

 after standing in the open air for some days, was evaporated, and 

 water added. No gas was disengaged, as the phosphuret had been 

 converted into a phosphat. The liquid being filtered and evapo- 

 rated, a tenacious substance remained, much resembling gum arabic. 

 Its taste was bitter, with a slight degree of sweetness. It did not 

 seem soluble in alcohol. It burned like gum. 



When sugar is distilled in a retort, there comes over a fluid 

 which at first scarcely differs from pure water; soon it is mixed with 

 what was formerly called pyromucous acid, is now known to be a 

 compound of oil and acetic acid ; afterwards some empyreumatic oil 

 makes its appearance, and a bulky charcoal remains in the retort. 

 This charcoal very frequently contains lime, because lime is used in 

 refining sugar ; but if the sugar, before being submitted to distilla- 

 tion, is dissolved in water, and made to crystallize by evaporation, 

 in a temperature scarcely higher than that of the atmosphere, no 

 lime whatever, nor any thing else, except pure charcoal, will be 

 found in the retort. During the distillation, there comes over a 

 considerable quantity of carbonic acid and carbureted hydrogen 

 gas. Sugar, therefore, is decomposed by the action of heat ; and 

 the following compounds are formed from it water, acetic acid, 

 oil, charcoal, carbonic acid, carbureted hydrogen gas. The quan- 

 tity of oil in a separate state is inconsiderable; by far the most 

 abundant product is pyromucous acid. Sugar, indeed, is very 

 readily converted iuto pyromucous acidj for it makes its appear- 

 ance always whenever syrup is raised to the boiling temperature. 

 Hence the smell of caromel which syrup at that temperature emits. 

 Hence also the reason, that, when we attempt to crystallize syrup, 

 by heat, there always remains behind a quantity of incrystallizable 

 matter, known by the name of melasses j w hereas, if the syrup is 

 crystallized, without artificial heat, every particle of sugar may be 

 obtained from it in a crystalline form. Hence we see the import- 

 ance of properly regulating the fire during the crystallization of the 

 sugar, and the saving that would probably result from conduct- 

 ing the operation at a low heat. 



We are indebted to Mr. Cruikshank for the most precise set of 



