& 
onthe Nature of Sugar. ° 367 
lutely neceffary for the conyerfion of yeretable mucilage and 
fecula into fugar. In no inftance was faccharine matter 
formed where this was not prefent. Mr. C. thinks that the 
oxygen.is chiefly abforbed by the barley, though part may 
alfo go to the formation of the carbonic acid ; for.carboni¢ 
acid was formed in confiderable quaatity without the pre- 
fence of oxygen gas, which he conceives muft proceed froma 
the decompofition of the water, its oxygen uniting with the 
carbonaceous principle of the barley, while its hydrogen, is 
fixed, which may be neceflary,to. the formation of the face 
charine principle. He infers, therefore, that vegetable, mu; 
cilage is conyerted, into fugar, by being, deprived of part of 
its-carbon, whileat the fame time it unites with a greater 
proportion of oxygen; and probably alfo with hydrogen from 
the decompofition of the water. Thus then both from ana- 
lyfis and fynthefis it appears that fugar contains more oxy- 
gen than gum or mucilage; and it fhould follow, that fugar 
deprived of its oxygen muft lofe its fweetnefs and form a 
kind of gum. To accomplith this was the object of the fol- 
Jowing experiments : 
Some fyrup was introduced into a jar filled with and in- 
verted over mercury: to this was admitted an equal quan- 
tity of the phofphuret of lime: a confiderable production of 
phofphoric gas almoft immediately took place, and the mer- 
ceury defcended in the jar, At the end of § days the fyrup, 
inftead of a {weet, had a bitter afiringent tafte. When fl- 
tered, alcohol produced a copious white precipitate in flakes, 
refembling mucilage feparated from water by the fame fuby 
ftance. 
To refined fugar diffolyed in alcohol phofphuret of lime 
was added: no gas was difengaged, nor any action produced. 
The mixture was allowed to remain in an open vial till the 
‘alcohol had evaporated ; diftilled water was added, but no 
difengagement of gas took place, the phofphuret having been 
decompofed and converted principally into phofphat of lime. 
The mixture being filtered and the clear liquor evaporated, 
I | there 
