SACCHARUM. 719 



fa 



J 



There is also present in the juice a very small amount of a slightly 

 aromatic substance (essential oil ?) to which the crude caue sugar owes 

 a peculiar odour which is not observed in sugar from other sources. 

 The first two classes of the above enumerated substances render the 

 juice tnrbid, and greatly promote its fermentation, but they easily 

 separate by boiling, and the juice may then be kept a short time with- 

 out undergoing change. In many colonies the yield is said to be far 

 inferior to what it should be; yet the juice is obtained in a state allow- 

 ing of easier purification, when its extraction is not carried to the 



furthest limit. 



In beet root as well as in the sugar cane, cane sugar only \vas said to be 

 present; leery however has proved that in the cane some uncrystallizable 

 (inverted) sugar is al ways present. Its quantity varies much, according 

 to the places where the cane grows, and its age. The tops of quick- 

 growing young canes yielded a vesou containing 24 per cent, of uncrystal- 

 hzable suaar- S-fi of cane suffar; and 94 of water. Moist and shady 



iHLixuLu sugar; do oi caue sugar, tinu i^t^ "^ „^^^.. — ^-~-- 

 situations greatly promote the formation of the former liind ot sugar 

 which also prevails in the tops, chiefly when immature. Hence that 

 observer concludes that at first the uncrystaUizable variety ot sugar is 

 formed, and subsequently transformed into cane sugar by the torce ot 

 vegetation, and especially by the influence of light. Perfectly ripened 

 canes contain only J, to X of all their sugar in the uncrystallizable state. 



Description and Chemical Composition-Cane sugar is the type 

 of a numerous class of well-defined organic ,<=oi«Pf "'^'' °*, fi^,"',?' 

 occurrence throughout the vegetable and animal kingdoms «''» ™"^|^^> 

 obtained by decomposing certain other substances; in ^/f ^Jfr case 

 however, glucose or some other sugar than cane sugar is obtamed^ Cane 

 sugar, &^mo^\ or C-H-(OH)^0^ melts, without change of ^o^P°«; 

 tion, at 160° C, several other kinds of sugar givmg f ^^'^t«> w^^*^ which 

 they form crystallized compounds at the ordinary temi^eratum 



Cane suga% forms hard eVystals of the obhque rhon^bic sj ste™, hawn„ 

 a sp. gr. of 1-59. Two parts are dissolved at io u. y j 



wate^' and by much les^at an elevated temperature > ^ f g'^o^^'^^P^^^'^'^f 

 of the thermometer is observable in the fomer casa One part ^^ 



sugar dissolved in one of water forms %Hf '^g^^J^P^^equires 65 parts 

 sugar in one of water, a liquid of sp. gr. 1 f " ^"°^ ^/^oh^l for solu- 

 of spirit of wine (sp. gr. 0-84) or 80 parts of anhjdrous alcono 



tion ; ether does not act upon it. „„„onns solution of cane 



A ray of polarized ligl't is deviated by ^^^'''^^loZL ''' ^'^* 

 sugar to the right, but by some other kinds of su|a ^ ^^^^^^ '^{^^ -^ ^^^ 

 shown by Biot.-" These optical powers are highly » P° ^^f ii^s con- 

 practical estimation of solutions of sugar, and m sc ^^ ^ ^.^_^^ ^^ ^^^^ ^ 

 nected with sugar or saccharogenous s"fstances^ circumstances, as the 

 chemical properties of sugar are altered by manj c ^^ ^^.^^^ ^^^^. 

 action of dilute acids or alkalis, or by the i™^"J^^J|j^j^ Other ferments 

 Yeast occasions sugar to undergo alcoholic Icim ' ^^.^ ^^^ produced, 

 set up an action by which butyric, lactic or propio ^ ^^^^ ^^^^^ ^^^^^^ 

 ^ Cane sugar is of a purer and sweeter taste ^^^_ 



Though it does not alter litmus paper, yet ^uth alkalis 



. ' It is commonly stated that three parts can be dissolved in one o 

 IS not. tliu f,„t 



not the fact. 



