on the Naiure of Sugar. 373 
frefh flacked quick lime, | and to another digefted with 
potath, fome good yeaft was added—to an equal quantity of 
folution of fugar alone the fame quantity of yeaft was added: 
the laft began to ferment in 12 hours, and in a few days ran 
into the acetous ftate—the other two-did not ferment: the 
temperature of the room during the experiments was from 
65° to 750, . 
A folution of the fugar of milk, to which a proper quan 
tity of yeaft was added, began to ferment im four days: at 
the end of 16, when the procefs had ceafed, it had the 
fmell of cyder, but rather more of the flavour of apples, 
was very four, and reddened the tinéture of litmus: with 
the oxyd of lead it formed a fweet faline mafs compofed of 
flender prifmatic oryftals, not deliquefcent —the acid there- 
fore contained, or was common vinegar. 
In the attempts to convert gum into fugar by combining 
oxygen with it, as before ftated, it ran into the acid flate. 
To fee if any thing like fermentation preceded this ftate, or if 
this effect could ke produced by mere expofure to the air, 
without the addition of fome fubftance containing much 
oxygen, as the nitrous or oxygenated muriatic acids, a folu- 
tion of gum arabic was mixed with yeaft as in the laft ex- 
periments, but no fermentation was perceivable at the end 
of 26 days. It appears that the azot and lime combined 
with the carbon in gum prevents the vinous, and confe- 
quently the acetous fermentation. Similar experiments 
were made upon a ftrong decoétion of beef, with, and with- 
out yeaft, but no fermentation followed. Indeed it has been 
fo generally. admitted that vegetable and animal mucila- 
ges, when pure, are not fufceptible of the yinous fermen- 
tation, that, had not a contrary opinion been lately advanced, 
thefe experiments upon them would have been conceived 
anneceffary, 
Bb3 TABLE 
