of a newly discovered vegetable acid. 245 
beautiful silvery crystals. Neither of these salts is soluble 
in 5000 times its weight of water. The sorbate when heated 
to redness, undergoes a somewhat brilliant combustion. 
The super-sorbate never assumes the solid form ; its taste 
is sweet. Thus the sorbic acid forms three combinations with 
lead : malic forms but two, the neutral malate, which is an 
uncrystallizable soft powder, and the super-malate. Not less 
distinguishable are the two acids by their combinations with 
the alkalies. 
Sorbate of potash, when there is an excess of acid, forms 
permanent crystals soluble in water, but insoluble in alcohol. 
Sorbate of soda, when there is an excess of acid, forms per- 
manent crystals, which agree in characters with the former. 
Sorbate of ammonia, when there is an excess of acid, also 
forms permanent crystals of similar characters with the pre- 
ceding. 
These three salts will not crystallize unless there be a tole- 
rable excess of acid ; they are to be considered as super-salts. 
That of soda even requires the aid of cold to render it solid. 
The malates of potash, soda, and ammonia are known to be 
uncrystallizable and deliquescent. 
In the combinations of these acids with earths, there are 
also striking differences. Scheele found, that when he added 
carbonate of lime to malic acid, a great quantity was dissolved, 
but the solution gave with litmus, indications of an abun- 
dant acid which it was impossible to neutralise with farther 
additions of chalk.* I obtained the same result with malic acid 
from the Sempervivum ; I even found that the solution might 
be boiled to dryness, on a fresh portion of carbonate of lime, 
* Scheele, Chem. Annal. 1785. 2. 292. 
