754 GRAPE SUGAR. 



cane sugar is carbonised in the same circumstances. On the 

 other hand, alkalies which do not alter the colour of cane sugar, 

 even at the boiling point, provided they are dilute, convert grape 

 sugar, with heat, into a brown or brownish black substance. The 

 compounds of grape sugar with barytes, lime and oxide of lead 

 are formed with difficulty, while a crystalline compound with 

 chloride of sodium is easily prepared. 



Compounds of grape sugar. According to the recent analyses 

 of Erdmann and Lehman, the compound of grape sugar and 

 chloride of sodium contains 2 atoms of water, which it loses at 

 212. Its formula in the crystallized state is 2(C 12 H 12 O 12 ) + 

 NaCl,2HO. This compound loses 3 atoms of water at 320 

 (160 cent.), according to Peligot, but then its sugar is modified. 

 The compound of grape sugar and oxide of lead, precipitated 

 on mixing the sugar with acetate of lead containing ammonia 

 (page 594), consists, according to the analysis of Peligot, as 

 corrected by Liebig, of C 12 H 11 O 11 + 3PbO, or in its formation 

 3 atoms of water are replaced by 3 atoms of oxide of lead. The 

 solutions of lime and barytes in grape sugar become brown, 

 when heated. 



Sulphosaccharic acid was formed by Peligot, by fusing 1 part 

 of crystallized starch sugar by the heat of a water-bath, and 

 then mixing the mass in small portions with concentrated sul- 

 phuric acid. The compound is then dissolved in water, and 

 saturated with carbonate of barytes, which precipitates sulphuric 

 acid, while the sulphosaccharate of barytes remains in solution. 

 The acid liberated from combination is a sweet liquid, feebly 

 acid, which forms soluble salts with almost all bases. The 

 solution of sulphosaccharic acid is easily decomposed by evapo- 

 ration, and resolved into sugar and sulphuric acid, which then 

 precipitates barytes. Its composition has not been determined 

 with certainty. 



Sacchulmine is a substance obtained in brown, brilliant, crys- 

 talline plates, by boiling cane sugar for a very long time in very 

 dilute sulphuric, hydrochloric or nitric acid ; it is insoluble in 

 ammonia. Sacchulmic acid, of which the formula is C 30 H 15 O 15 , 

 according to Malaguti, is formed at the same time, and many 

 may be separated by ammonia, in which it is soluble, from 

 sacchulmine. 



Glucic acid is formed when a saturated solution of lime or 



