$8 NUTRITIVE PLANTS. 



it refuses to unite with it, but swims on. the top in a state of 

 purity. 



The acids are capable of dissolving sugar, and those which are 

 concentrated decompose it. Sulphuric acid very soon acts upon it ; 

 water is formed, and perhaps also acetic acid ; while charcoal is 

 evolved in great abundance, and gives the mixture a black co- 

 lour, and a considerable degree of consistency. The charcoal may 

 be easily separated by dilution and filtration. When heat is ap- 

 plied, the sulphuric acid is rapidly converted into the sulphureous 

 acid. 



Nitric acid dissolves it with effervescence, occasioned by the evo- 

 lution of nitrous gas, and converts it into malic aud oxalic acids. 

 480 arains of sugar, treated with six ounces of nitric acid diluted 

 with its own weight of water, and cautiously heated, separating the 

 crystals as they are formed, yielded 280 grains of oxalic acid ; so that 

 100 parts of sugar yield by this treatment 58 parts of oxalic acid. 

 When liquid oxy muriatic acid is poured upon sugar in powder, it is 

 dissolved, aud immediately converted into malic acid ; and the oxy- 

 muriatic acid is converted into common muriatic acid. 



Sugar absorbs muriatic acid gas slowly, aud assumes a brown 

 colour and very strong smell. The vegetable acids dissolve it ; but 

 seemingly without producing any alteration on it. 



The action of the oxides of carbon and azote upon sugar has 

 scarcely been examined. 



Sugar is soluble in alcohol, but not in so large a proportion as in 

 water. According to Wenze], four parts of boiling alcohol dissolve 

 one of sugar. It unites readily with oils, and renders them miscible 

 with water. A moderate quantity of it prevents, or at least retards, 

 the coagulation of milk ; but Scheele discovered that a very large 

 quantity of sugar causes milk to coagulate. 



The hydrosulphurets, sulphurets, and phosphurets of alkalies, and 

 alkaline earths, seem to have the property of decomposing sugar,and 

 of bringing it to a state not very different from that of gum. Mr. 

 Cruikshank introduced a quantity of syrup into a jar standing over 

 mercury, and then added about an equal quantity of phosphuret of 

 lime. Phosphureted hydrogen gas was immediately extricated. 

 In eight days the syrup was withdrawn : it had lost its sweet taste, 

 and acquired a bitter and astringent one (the taste of phosphuret of 



