A en 
402 “TARTARIC ‘ACID. 
colour, often slightly wrinkled, and from one- 
eighth to two-eighths of an inch in diameter. 
This plant is much less esteemed than any of the 
varieties of the common lentil, yet is cultivated, 
for the sake of both its herbage and its seeds, in 
some parts of France ae of other Continental 
countries. 
The tare-lentil or vn -tare, Ervum ervilia, 
was introduced to Britain from the South of Ku- 
rope toward the close of the 16th century. It 
closely resembles the preceding in height, habit, 
flower, and pod, and is also cultivated.—The slen- 
der and the pubescent tares, &. gracile and £L. 
pubescens, the former pale blue flowered, the lat- 
ter purple flowered, and both similar to the two 
preceding in height, habit, and pod, were intro- 
duced within the last 30 years from the South of 
Europe. 
The small lentil tare, Zrvwm lenticula, was in- 
troduced in 1820 from Carinthia. It has a gene- 
ral resemblance, especially in pod, to the common 
Jentil; but is regarded by some botanists as a 
chick-pea. Its flowers are blue—The blackish 
tare, H. nigricans, was introduced from Tauria 
in 1817. It still more closely resembles the 
common lentil; but has purple-coloured flowers. 
—The two- seeded tare, L. dispermum, was intro- 
duced from India in 1802. It is somewhat lentil- 
like, and has a height of about 20 inches, and 
carries purple-coloured flowers. 
TARTAR. See Trerx. 
TARTAR (Cream or). 
TAR. 
TARTAR EMETIC. See Anrrmony. 
TARTARIC ACID. This acid, as it exists in 
vegetables, is usually combined with potash, 
forming a salt with an excess of acid—the super- 
tartrate or bi-tartrate of potash. This salt is 
deposited in considerable quantity from the juice 
of the grape during its conversion into wine, or 
rather from the wine during the slow fermenta- 
tion which it suffers in the cask. It does not 
appear to be a product of the fermentative pro- 
cess, but exists before this in the juice of the 
grape, and is merely separated. It also exists in 
other fruits, particularly in the tamarind, of 
which it forms a considerable part. As deposited 
from wine, it is impure, having mingled with it 
colouring matter and tartrate of lime. In this 
state, it forms the crude tartar of commerce, 
named whzte or red tartar, according to its colour, 
It is purified by boiling it in water, with the ad- 
dition of a small quantity of fine clay, which at- 
tracts the colouring matter. By evaporation, it 
is obtained crystallized, forming the purified tar- 
tar, crystals, or cream of tartar of the shops. 
From this salt the tartaric acid is obtained, by 
adding to a solution of the super-tartrate of po- 
tash in boiling water, carbonate of lime in pow- 
der, as long as any effervescence is excited: the 
tartrate of lime which is formed and precipitated, 
being well washed, is decomposed by adding sul- 
phuric acid equal in weight to the chalk that 
See Cream or TaArR- 
—TAUSCHERIA. 
had been employed, previously diluted with half 
its weight of water, digesting them with a mode- 
rate heat: the sulphuric acid combines with the 
lime and forms the sulphate, which, being of 
sparing solubility, is separated, while the tartaric 
acid is dissolved by the water, and, by evapora- 
tion, is obtained in a crystallized form. The 
crystals are tables or prisms, white, and nearly 
transparent. Their taste is sour, and they deeply 
redden vegetable blues. They are very soluble 
in water, and form a solution so concentrated as 
to have an oily appearance. By the action of 
very strong nitric acid, tartaric acid is converted 
into oxalic acid. The crystals are composed of 
acid 66 and water 9 in 75 parts. The acid ap- 
pears to be composed of 
Hydrogen, . : , 4°48 
Carbon, : 4 35 82 
Oxygen, ; 39 70 
100-00 
Tartaric acid is decomposed by heat, affording, 
among other products, a white sublimate, which 
is a peculiar acid, named, from its origin, pyro- 
tartarve acid, which has been regarded by some 
as acetic acid disguised by the addition of a little 
oily matter. Tartaric acid combines with the 
alkalies and earths, forming salts named ¢artrates. 
The acid appears to have a peculiar tendency to 
enter into combination with more than one base, 
and to form ternary salts. It has also a tendency 
to form salts with an excess of acid, in uniting 
with those bases, with which it forms soluble 
compounds, Tartrate of potash is usually formed 
by neutralizing the excess of acid in the bi-tar- 
trate, by the addition of carbonate of potash. 
From its affinity to water, it is not easily crys- 
tallized, but, by a slow evaporation, affords four- 
sided prisms. It is deliquescent in a humid 
atmosphere, and very soluble in water, whence 
its name, also, of soluble tartar. Tartrate of soda 
is soluble and crystallizable. A triple salt, the 
tartrate of potash and soda, or ochelle salt, is 
formed by neutralizing the excess of acid in the 
super-tartrate of potash, by adding carbonate of 
soda. See the article Rocnente Sar. Tartaric 
acid acts on some of the metals, and it may be 
combined with the oxides of all of them by double 
affinity. By employing the bi-tartrate of potash 
to act on these oxides, ternary compounds are 
obtained. The most important of these is that 
formed with the oxide of antimony,—long known 
in medical practice under the name of tartar 
emetic, as one of the mildest and most manage- 
able of the antimonial preparations. See the 
article ANTIMONY. 
TARTONRAIRA. See Dapune. 
TARUGA, See ALPACA. 
TAUSCHERIA. <A small genus of hardy, or- 
namental, exotic, annual plants, of the cruciferous 
order, ‘Two species, the naked-podded and the 
hairy-podded, both about 6 inches high, white- 
flowered, and blooming in June and July, were 
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