CON 
COP 
431 
jtfso. brassica marina, grows naturally on the 
sea-beach in many parts of England, but 
cannot belong preserved in gardens. It has 
many small white stringy roots, which spread 
wide, and send out several weak trailing 
branches. These twine about the neighbour- 
ing plants like tiiose of the common bind- 
weed, with kidney-shaped leaves like those of 
the lesser celandine. The flowers are pro- 
duced on the side of the branches at each 
| joint. They are of a reddish-purple colour, 
t and appear in July. They are succeeded by 
round capsules, having three cells, each con- 
I taming one black seed. 
9 The turpethum is a native of the island 
of Ceylon. This has .fleshy thick roots which 
spread far in the ground ; and abound with a 
milky juice that flows out when the roots are 
broken or wounded, and soon hardens into 
i a resinous substance when exposed to the sun 
. and air. From the root shoot forth many 
twining branches, which twist about each 
ether, or the neighbouring plants, like the 
common bind-weed. They have heart-shap- 
ed leave- that are soft to the touch, tike those 
of the marshmallow. The flowers are pro- 
duced at the joints on the side of the stalks, 
several standing together on the same foot- 
stalk: they are white, and shaped like those 
! of the common great bind-weed ; and are 
succeeded by round capsules, having three 
cells containing two seeds each. 
10. The jalappa, or jalap, used in medi- 
cine, is a native of Aleppo in Spanish Ame- 
rica, situated between La Vera Cruz and 
Mexico. It has a large root of an oval form, 
full of a milky juice; from which come 
out many herbaceous twining stalks, rising 
eight or ten feet high, with variable leaves ; 
some of them being heart-shaped, others an- 
gular, and some oblong and pointed. They 
are smooth, and stand upon long footstalks : 
; the flowers are shaped like those of the com- 
mon greater bind-weed, each footstalk sup- 
porting only one flower. See PL N. H. fig. 142. 
The second sort is propagated by seeds, 
which must be sown on a border of light 
| earth. The plants must have some tall stakes 
placed near them for their branches to twine 
about, otherwise they will spread on the 
[ ground, and make a bad appearance. The 
third sort is annual, and must be propagated 
by seeds sown on a hotbed in spring; and 
towards the end of May they should be plant- 
j ed out in warm borders, and treated in the 
same manner with the former. The fourth 
| species is. sometimes propagated in this coun- 
| try. The roots must be planted on a hot- 
I bed in the spring: and if the plants are co- 
| vered in bad, weather with glasses, they will 
j produce flowers, and some small bulbs from 
the joints of the stalks ; but if they are ex- 
; posed to the open air they seldom grow to 
j any size. Tire fifth is propagated by laying 
down the young shoots in the spring, which 
| generally put out roots in three or four 
months: they may then be taken from the 
old plants, and each placed in a separate pot, 
which is to be set in the shade till they have 
.taken new root; after which they may be 
placed with other hardy greenhouse plants 
till autumn, when they should be removed 
into the greenhouse, and afterwards treated 
•in the same manner as myrtles and other 
i greenh mse plants. The turbith and jalap 
are too tender to live in this country, unless 
they are constantly, kept in a stove.. The 
COP 
' other species require no particular directions 
for their cultivation. 
The root of the first sort proves a very 
acrid purgative to the human race, but is 
eaten by hogs in large quantities without any 
detriment. The inspissated juice of the se- 
cond species is used in medicine as a strong 
purgative ; as are also the roots ot the jalappa 
and turpethum. The soldanella has likewise 
been used with the same intention. Half an 
ounce of the juice, or a drachm of the pow- 
der, is an acrid purge. 1 he leaves applied 
externally are said to diminish dropsical 
swellings of the feet. See Materia Me- 
dic a. 
CONVOY, in marine affairs, one or more 
ships of war, employed to accompany and 
protect merchant ships, and prevent their 
being insulted by pirates, or the enemies of 
the state in time of war. 
Convoy, in military affairs, a detachment 
of troops employed to guard any supply of 
men, money, ammunition, provisions, stores, 
&c. conveyed in time of war, by land or sea, 
to a town or army. A body of men that 
marches' to secure anything from falling into 
tiie enemy’s hand, is also called a convoy. 
An officer having the command of a convoy 
must take all possible precautions for its se- 
curity ; and endeavour, before its march, to 
procure some good intelligence concerning 
the enemy’s out -parties. And as the com- 
manding officer of the place from which the 
convoy is to march, and those ot such other 
places as he is to pass by, are the most pro- 
per persons to apply to for assistance ; he 
must therefore take such measures as wiil 
enable him to keep up a constant intercourse 
with them. The conducting a convoy is one 
of the most important and most difficult of all 
military operations. 
CONVULSION, spasmus. See Medi- 
cine. 
CONYZA, Jleabane, a genus of the poly- 
gamia superflua order, in the syngenesia class 
of plants, and in the natural method ranking 
under the 49th order, compositai. 1 he pap- 
pus is simple, the calyx imbricated and round- 
ish, the corolluhe of the radius triiid. There 
are 41 species, none of which merit any par- 
ticular description. 
COOMB or comb of corn, a dry mea- 
sure containing four bushels, or half a quar- 
ter. 
COOPER, one who manufactures casks, 
tubs of all sizes, pails, and some other similar 
articles used in domestic concerns. 'These 
are made generally of oak timber ; a great 
part of which comes from America, cut up 
into narrow pieces or staves ; they are 
sometimes bent, and sometimes straight, ac- 
cording to the purposes tor which they are 
wanted. ' The staves are kept together by 
means of hoops, made from hazel or ash, or of 
iron. To make them hold water, or other li- 
quids, split flags are inserted, which swell by 
moisture, and effectually prevent the vessels 
from leaking. 
Coopers, by 23 H. VIII. c. 4, shall make 
their vessels of seasonable wood; and make 
them with their own marks, on forfeiture of 
3,y. 4c l . : and the contents of vessels are ap- 
pointed to be observed under a like penalty. 
COPAIBA, or ba.sam of copaiba, a liquid 
resinous juice, flowing from incisions made 
in the trunk of the copaifera balsamum. 
Pure balsam of copaiba dissolves entirely in 
6 
rectified spirit, especially if the menstruum 
is previously alkalized. Distilled with water 
it yields a large quantity of a limpid essential 
oil ; and in a strong heat, without addition, 
a blue oil. See next article. 
COPAIFERA, a genus of the monogynia 
order, in the decandria class of plants, and 
in the natural method ranking under those of 
which the order is doubtful. There is no ca- 
lyx ; there are four petals; the legumen 
ovate ; one seed with an ariilus, or coat, re- 
sembling a berry. We know of but one spe- 
cies, the officinalis, which yields the copaiba 
balsam mentioned in the preceding article. 
'This tree grows near a village called Ayapei, 
in the province of Antiochi, in the Spanish 
West Indies, about ten days journey from 
Carthagena. There are great numbers of 
these trees in the woods about this village, 
which grow to the height of 30 or 60 feet. 
Some of these trees do not yield any of the 
balsam ; those which do are distinguished by 
a ridge which runs along their trunks. These 
trees are wounded in the centre; and cala- 
bash shells, or some other vessels, are applied 
to the wounded part to receive the balsam, 
which will all flow out in a short time. One of 
these trees will yield live or six gallons of 
balsam: but though they will thrive well after 
being tapped, yet they never afford any more. 
CuPAL, a substance of great importance 
as a varnish, obtained from the rims copali- 
nuin, a tree in North America. It is a beau- 
tiful transparent resinous-like substance. 
When heated it melts like other resins; but 
it differs from them in not being, soluble in 
alcohol, nor in oil of turpentine without pe- 
culiar management. Neither does It dis- 
solve in the fixed oils like other resins. The 
specific gravity of copal varies from 1.045 to 
1.1 39- Mr. Hatchett found it soluble in al- 
kalies and nitric acid with the usual pheno- 
mena ; so that in this respect it agrees with 
the other resins. The solution of qopal in 
alkalies he found indeed opalescent, but it is 
nevertheless permanent. It deserves atten- 
tion, that he found resin when dissolved in. 
nitric acid, and then thrown dow n by an al- 
kali, to acquire a smell resembling that of 
copal. 
When copal is dissolved in any volatile li- 
quid, and spread thin upon wood, metal, pa- 
per, & c. so that the volatile menstruum may 
evaporate, the copal remains perfectly trans- 
pa ent, and forms one of the most beautiful 
and perfect varnishes that can well be con- 
ceived. The varnish thus formed is called 
copal varnish, from the chief ingredient in it. 
This varnish was first discovered in France, 
and was long known by the name of vernis 
martin. The method of preparing it is con- 
cealed ; but different modes of dissolving co- 
pal in volatile menstrua have been from time 
to time made public. The following are the 
most remarkable of these : 
When copal is kept melted till a sour- 
smelli', g aromatic odour has ceased to pro- 
ceed from it, and then mixed with an equal 
quantity of linseed oil which has been 'de- 
prived of all colour by exposure to the sun, 
it unites with the oil, and forms a varnish, 
wli.ch must be dried in the sun. 
When copal is treated with oil of turpen- 
tine in close vessels, the vapour, being pre- 
vented from escaping, exerts a greater pres- 
sure, and the heat rises above the boiiiqg 
point. This additional heat is said to. enable 
