on the Nature of Sugar.” 369 
alcohol, the fweetnefs was completely reftored. When al- 
cohol was added to a folution of {ugar and pure potath, after 
it had beem boiled: to the confiftencé of a fyrup, no union 
took place : though agitated, the alcohol ftill fwam pure on 
the top—which feems to prove that a new compound is 
formed by thefe fubftances, infoluble in this fluid, e.* 
both are completely fo in a feparate ftate. 
Having converted fugar into a {pecies of gum, by nt om 
ing a portion of its oxygen, feveral experiments were made 
to change gum, by adding oxygen, into a kind of fugar, but 
without fuccefs. The gum went rapidly into the acid ftate, 
efpecially when expofed to the aétion of the oxygenated mu- 
riatic acid gas. . From the failure of thefe trials, it was fuf- 
pected that mucilages were not fo fimple as had been gene-. 
rally duppofed :. to throw fome light on this fubject the: fol- 
lowing comparative experiments were made : 
An ounce of powdered gum arabic was expofed to heat in 
a coated glafs retort, as in the firft. two experiments, only 
- here the pneumato-chemical apparatus was adapted—the 
heat was gradually applied as before*. The charry refi- 
duum burned very flowly; but when expofed to a ftrong 
heat in an open. crucible, it left a whitith powder, which was 
found to be lime and a {mall proportion of calcareous phof- 
phat. The pyromucous acid being fuperfaturated with lime, 
a ftrong. {mell..of ammonia was inftantly perceived ; anda 
piece. of paper dipped im muriatic acid being held over. the 
veffel, copious. white fumes were immediately produced— 
azote therefore forms a conftituent part of the gum. The 
gas collected in. the pneumatic apparatus was carbonic acid 
mixed with that fpecies of hydrocarbonat which is obtained 
_by heat from moiftened charcoal. Two ounce meafures of 
the gas, well freed from carbonic acid, were mixed with T£ 
soya pure oxygen gas, and fired, by the ele&tric fpark, jn 
# For the amoyat of the ns in this and the fubfequent expetin 
ments fee the table, page 374 
Vor Tio sts So Bb , Py ftrong 
