246 Mr. Donovan on the nature and combinations 
yet when lixiviated, the filtered solution would still redden 
litmus, and the salt finally afforded was readily soluble. These 
results often obtained, prove that it is not possible to form 
neutral malate from carbonate of lime. 
But with sorbic acid the case was quite different. When 
it was diluted, and agitated for a little while with carbonate 
of lime, the solution, before it could be filtered, deposited the 
principal part of the sorbate in the form of a discrete, gritty 
powder. The liquor when filtered produced no redness in 
tincture of litmus, and every thing proved that the fluid by 
mere agitation over the carbonate, had been completely neu- 
tralised. 
The same results which Scheele obtained from lime were 
afforded by carbonate of barytes : but with sorbic acid I pro- 
duced a liquor which showed no signs of acidity. The best 
test for ascertaining this fact, seemed to be infusion of brazil 
wood altered by distilled vinegar; and with this it even 
appeared, that the- solution contained an excess of base. 
Thus it appears, that malic acid never forms with carbo- 
nate of lime, any other than acidulous salts ; and, as Scheele 
observes, these solutions in some days deposit the neutral salt 
in crystals. But with these carbonates, the sorbic acid forms 
neutral salts , which, as soon as formed, precipitate. 
Scheele ascertained, that malate of magnesia is a delique- 
scent salt,* and in my trials I could not obtain it in a crystal- 
line form. When evaporated, it became thick, and dried 
into a semitransparent substance, which softened with the 
smallest quantity of water, and formed matter of a syrupy 
consistence. The same earth, heated in sorbic acid, afforded a 
* Creh’s Chem. Annal. 1785.2. 297. 
