GRAMINE^. 599 



b ■ 



h 



for solution about 80 parts of boiling absolute alcohol, 28 parts 

 of boiling officinal alcobol, and about 4 parts of boiling alcobol, 

 spec. gray. 'S-SO, these solutions depositing most of the sugar on 

 cooling. The solubility is greater in weak alcohol, both cold 

 and hot. At 15° C. 1 part of sugar dissolves in 2 parts of 

 50 per cent, alcohol, in 77 parts of 7b per cent, alcohol, in 

 14'7 parts of 80 per cent, alcohol, in 31-6 parts of 85 per cent. 

 alcohol, in 175 parts of 92 per cent, alcohol, and in 228 parts of 

 methylic alcohol of the same strength {Casamajor). Sugar 

 dissolves also in glycerin, the solubility being increased on 

 dilution with water, but it is insoluble in ether, chloroform, 

 carbon disulphide, and in hydrocarbons. It combines with 

 chloride of sodium, yielding deliquescent crystals which contain 

 14'9 per cent, of that salt. Definite compounds have Likewise 

 been obtained with several other salts and with alkalies and 



+ 



alkaline earths. When triturated in the dark it becomes luminous. 

 Its solution deviates polarized light to the right — a behaviour 

 which is of great practical importance for the estimation of 

 sugar in aqueous liquids and for distinguishing different kinds 

 of sugar which have a different rotary power. 



When sugar is heated to 160° C. it melts without losing in 

 Weight, and congeals on cooling to a transparent amorphous 

 yellowish mass known as harley-sugar, saccharum Jiordeatum, 

 which becomes gradually opaque on the surface from the 

 formation of minute crystals. If sugar is kept in the melted 

 state between 160° and 170° C. for a short time, it is converted 

 into a deliquescent mixture of glucose and levitlosan ; C^H^'^O^^ 

 yields C'H'^O^ + CH'^O^; the latter is not fermentable until 

 after it has been boiled with water or dilute acids. When 

 teated to between 180° and 200° C. sugar turns brown, evolves 

 a peculiar odour, and is converted into caramel, C^^H^''0% 

 parting at the same time with 2H'0 ; the pure product of this 

 composition, caramelan,was obtained colourless by Gelis (1862). 

 Caramel may be prepared in the same manner from inferior 

 qualities of sugar, from molasses, and from glucose, and the 

 conversion is hastened in the presence of small quantities of 

 alkalies ; the addition of a little carbonate of ammonium, which 



