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L 
802 CHOREA. 
not being saponifiable with potash, and by re- 
quiring a heat of 278° for its fusion. When 
cholesterine is decomposed by the action of its 
own weight of hot concentrated nitric acid, a 
peculiar substance is deposited, of butyraceous 
odour, slightly styptic taste, and insoluble in 
water, called cholesteric acid. Cholesterine has 
been found also in the biliary concretions of the 
ox, the pig, and the dog. 
CHOREA. A violent convulsive motion in one 
or more muscles of the limbs. It occasionally, 
yet very seldom, occurs in the horse. No cure 
for it is known; but it is not supposed to be at- 
tended or followed by worse effects than tempor- 
ary pain and lameness. 
CHORISPORA. A genus of hardy, annual 
plants, of the cruciferous family. Only four or 
five species are known; but, though closely allied 
to the radish genus, they possess little interest. 
One of them, Chorispora tenella, formerly called 
Raphanus tenellus, is sometimes cultivated as an 
ornamental plant. It was introduced from Siberia 
in 1780; and it grows 6 or 7 inches high, and 
carries a purple flower in June and July. 
CHORIZEMA, or CuHorozema. A genus of 
beautiful, evergreen, New-Holland undershrubs, 
of the sophora division of the pea family. Some 
botanists derive the name from a word signify- 
ing to separate, and refer it to the fact of the 
fruit consisting of two perfectly distinct parts; 
others derive it from the same word, and refer it 
to the free or separated condition of the stamens ; 
and others derive it from two words signifying 
‘dance’ and ‘drink,’ and refer it to the circum- 
stances in which the first plant of the genus was 
discovered. Three fine species, the dwarf, the 
holly-leaved, and the rhomb-leaved, were intro- 
duced to Britdin in 1803; a superb species, C. 
Henchmanii, was introduced in 1824; four beau- 
tiful species, C. triangulare, C. ovatum, C. corda- 
tum, and C. spartiodes, were introduced about 
1830 and 1832 ; and several gorgeous species were 
introduced by seeds in 1836, and the immediately 
following years. The various-leaved species, C. 
varium,—called also C. elegans, and C. latifoliwm, 
was introduced, under the name of the Native 
Pea, from the Swan River in 1837. It has green- 
ish-grey leaves, and splendid racemes of orange 
and crimson flowers; and, from the very first 
sowings, it sported into two or three distinct 
varieties. It grows with much vigour, and is 
readily propagated from cuttings of its half- 
ripened shoots. Dickson’s species, C. Dicksonii, 
was first raised in this country by Messrs. Dick- 
son of Edinburgh, from seeds obtained in 1836 
from the Swan River; and while equal to most 
of the other species in splendour, it excels them 
in the size of its flowers. Most of the chorizemas 
have a height of from 9 to 30 inches; some have 
avery straggling habit of growth, and, apart from 
the singular beauty of their flowers, are awkward 
| and unsightly plants; and one or two are so ut- 
| terly feeble as to succeed best upon such cage- 
| 
CHRIST'S THORN. 
work as is commonly used for Tropceolum trico- 
lorum ; but, as a whole, they have already become 
well-known and highly-prized occupants of the 
greenhouse. | 
CHRISTMAS ROSE,—botanically Helleborus 
Niger. A hardy, ornamental, evergreen, herba- 
ceous plant, of the ranunculus tribe. It grows 
wild in Austria, and in the regions of the Alps 
and the Apennines, and was introduced to Bri- 
tain toward the close of the 16th century. Its 
root consists of many thick, fleshy fibres, which 
spread far into the ground; its leaves consist of 
7 or 8 thick, fleshy, obtuse, slightly-serrated lobes, 
and have their bases joined to the base of the 
flower-stems, and lie close to the ground; the 
flower-stems are naked, rise immediately from 
the roots, and attain a height of about a foot, 
each supporting a single flower; and the flowers 
are large, whitish, and five-petalled, and bloom 
from January till March. The plant takes its 
popular name of Christmas Rose from its habit 
of flowering in winter; it freely blooms in the 
parterre at a time when scarcely another hardy 
herb is fully in flower; it is a common favourite 
in all sorts of flower-gardens, from the most ex- 
tensive to the mere cottage plot; and it is readily 
propagated by separating the roots in autumn. 
A narrow-leaved variety, 7. n. augustifolius, is 
much later in flowering than the normal plant, 
being usually in bloom in March and April. 
CHRIST’S THORN,—botanically Paliurus. A 
small genus of hardy, deciduous, ornamental 
shrubs, of the buckthorn tribe. The common or 
pointed species, Paliurus aculeatus, formerly called 
Rhamnus Paliurus, is a native of Spain, Portugal, 
Italy, Palestine, and other countries bordering 
on the Mediterranean, and was introduced to 
Britain toward the close of the 16th century. It 
usually grows to the height of about 4 or 5 feet, 
but may be trained to an upright stem, so as to 
attain a far greater height, and to send out on 
all sides numerous slender branches. ‘Two sharp 
thorns occur at each joint of the branches,—the 
one straight, upright, and about half an inch 
long, and the other bent backward, and scarcely 
one quarter of an inch long; between the thorns 
is the bud for next year’s shoot; the joints go 
alternately in and out, so as to form at each bud 
an obtuse angle; and the thorns have a reddish 
colour, while the bark of the branches is smooth 
and purplish. The leaves are alternate, oval, 
pale green, and scarcely an inch in length, and 
stand on very short footstalks. The flowers have 
a yellowish colour, are produced in clusters from 
the sides of the young shoots, appear in June and 
July, and, though individually small, exist and 
flourish in such profusion as to make a very good 
show. The fruit is a two-celled nut, covered by 
a membrane or berry. This plant takes its name 
of Christ’s Thorn from the supposition that it 
was the plant of which the crucifiers of the Lord 
of Glory formed his ignominious crown of thorns. 
The word translated “thorns” in the sacred nar- 
