MANUFACTURE OF SUGAR IN BARBADOES. 
57 
exception of nitric acid, which occasions after a, time a very 
slight precipitate. Corrosive sublimate gives a similar re- 
sult. The ordinary tests discover the presence of salts of 
lime and magnesia, sulphuric and phosphoric acids, potash 
and soda, in variable quantities. A large addition of alco- 
hol throws down flocks of a substance resembling gum or 
dextrine, and, lastly, a few drops of sulphate of copper, and 
an excess of caustic potash occasion on heating a very abun- 
dant red precipitate of suboxide of copper, the well known 
mark of the presence of glucose or grape sugar. 
When lime-water is added in slight excess to cane-juice 
a copious precipitate falls, which consists of an azotized 
organic substance in combination with lime, waxy or fatty 
matter, and the phosphates of lime and magnesia, the latter 
constituting more than a fourth part of the dried mass. A 
similar precipitate is caused by potash and ammonia. The 
juice therefore appears to contain the following substances, 
cane-sugar in great quantity ; a notable amount of glucose, 
or sugar of fruits ; gum or dextrine ; phosphates of lime and 
magnesia retained in solution ; some other salt of lime and 
magnesia ; sulphates and chlorides ; potash and soda ; and, 
lastly, a peculiar azotized matter belonging to the albumi- 
nous family hitherto undescribed, capable of forming an in- 
soluble compound with lime, not eoagulable by heat or 
acids, and readily putrefiable. Of ordinary vegetable albu- 
men there are but indistinct traces, and of caseine or legu- 
mine none. 
Cane-juice, left to itself a few hours at the ordinary tem- 
perature of tropical countries (80° or thereabouts,) becomes 
very turbid, begins to disengage gas, and deposits a copious 
flocculent precipitate. In this state it is acid to test paper, 
and offensive to the smell. The boiled juice keeps better, 
and that which has undergone the lime-defecation may be 
kept unchanged for twenty or twenty-four hours, after 
which period it also becomes turbid and spoils. 
