Bi-Malate of Lime in the Berries of the Sumach. 57 
few drops in a platinum capsule and then igniting, or by add- 
ing to the liquor a little oxalate of ammonia. 
So abundant is the bi-malate of lime in the infusion of the 
berries both of the R. glabrum and copallinum that when re- 
duced by evaporation the whole liquid has the appearance of 
a thick light varnish and is almost insoluble in alcohol, two 
characteristic properties of the bi-malate. The process of 
Mr. Cozzens for preparing a pure malic acid from these ber- 
ries is therefore liable to the objection that by using alcohol 
as the solvent, the operator will lose all the malic acid which 
exists in the bi-malate, and this I am inclined to think is nearly 
all the malic acid of the infusion. From the very small 
portion of acid matter which alcohol imbibes by standing for 
some time over the inspissated infusion, it is obvious that lit- 
tle uncombined malic acid can be present. In fact, nearly 
all the acid kind in the Rhus exists as a bi-malate in com- 
bination with lime. In procuring malic acid from the juice 
of the Sorbus in which it exists in an uncombined state, the 
alcohol acts as a solvent of the acid, and is therefore em- 
ployed with advantage to separate it from mucilage and the 
other substances with which it is mingled. But it is entirely 
inadmissible when the acid is to be procured from the bi-ma- 
late of lime. 
The Bi-malate of Lime is readily procured from the ber- 
ries in considerable quantity and perfectly pure by the follow- 
ing process : 
A quantity of hot rain water or distilled water is poured 
over the berries in a clean earthen or wooden vessel. After 
allowing the berries to macerate for a day or two, the liquid 
is poured off and evaporated carefully in an earthen or porce- 
lain dish until it becomes intensely acid. It is now filtered 
through animal charcoal or bone black, repeatedly washed 
with muriatic acid. The liquid passes through almost co- 
lourless having only a slight amber tint. If the evaporation 
has been carried sufficiently far, a large deposit of crystals 
will form in a few hours. The liquid being poured off and 
further reduced by evaporation an additional crop of crys- 
You I— No. 1 8 
