COG 
'fize of a fiTiall pea, and fiirniflied with fix feet, and 
a fnout or trunk. It brings forth it's young alive, 
,and is nouriflied by fucking the juice of the plant 
on which it refides. It's body cohfifts of feveral 
annulations ; and, when" once fixed on the plant, 
it continues immoveable, being fubjefl to no far- 
ther change. Some pretend that there are two 
forts of thefe infects: the one domeftic, which is 
efteemed the beft; and the otlier wild, which is of 
a vivid colour. However, they appear to be the 
fame: with this difference only, that the wild infe6l 
feeds on uncultivated trees, without any afliftance 
from man ; whereas the domeftic one is carefully 
removed to cultivated trees atftated intervals, where 
it imbibes a purer juice. 
Thofe perfons who tend thefe infedls, place them 
on the prickly-pear plant in a certain order, and are 
very afTiduous in defending them from other infe£ls ; 
and if any foreigners happen to mix with them, they 
'are cai efully feparated by miCans of foxes tails. To- 
wards the clofe of the year, when the rains and cold 
-v/eather approach, which generally prove fatal to 
-their exiftence, the feeders take off the branches or 
leaves that are covered with the Cochineal, which 
have not attained their utmoft degree of perfeftion, 
and keep them under fhelter till the end of winter. 
Thefe leaves, v/hich are very thick and juicy, fup- 
yly the infefts with fufficient nourifhment while 
they are houfed. When m.ilder weather returns, 
and thefe animals are about to exclude their young, 
the natives form nefts for them, of a fize and con- 
-ftruftion adapted to their natures and neceffities ; 
and place twelve of them in every neft. Thefe 
nefts they affix to the thorns of the prickly-pear 
plant; and, in the fpace of three or four days, the 
infefts bring forth their young, which leave the 
nefts in a very ftiort time afterwards, and creep on 
the branches of the plant till they find proper places 
to repofe and receive their nouriiliment, and till 
the females are fecundated by the males, which, 
as in the cocci, differ very widely from the females, 
being winged infefts; whereas the others only 
creep, or are at moft ftationary. When they are 
impregnated, they produce a nevyr offspring ; fo that 
the propagator enjoys a triple harveft every year. 
When the native Americans have coUedted the 
Cochineal, they depofit them in holes in the ground, 
where they deftroy them by means of boiling wa- 
ter, and afterwards either dry them in the fun, in 
ovens, or on hot plates. From thefe various me- 
thods of curing them the different colours obferv- 
able in thofe imported are chiefly produced. Thefe 
infe£ls, while alive, feem to be fprinkled over with a 
white powder, which dilappears as foon as the boil- 
ing water is poured on them. Thofe v/hich are 
dried by preternatural heat are confiderably blacker 
■than the reft; but it fhould be underftood that, 
whatever colours they pofiefs, they are all females, 
the males, as already obferved, being winged in- 
ie£ts, and of no value. 
Cochineal is ufed in medicine as v/ell as dyeing, 
and is faid to poffefs nearly the fame virtues as the 
:fcocGus orkermes; but isfeldom adminiftered alone, 
and is probably ufed rather for the fake of it's co- 
lour than it's medical eftecls. When infufed or 
^boiled in water. Cochineal yields a crimfon tinc- 
ture, inclining to a purple: fixed alkali renders the 
-crimfon deeper, but leffens it's luftre; v/hile vola- 
• tile alkali heightens the colour, v/ithoutdiminifning 
it's luftre. The beft m.ethod of applying volatile 
^^Ikali to this purpofe in dyeing, is to dip the cloth, 
: when dyed with Cochineal, in a Ibiution of fal am- 
c o c 
moniac, and then to throw fome pot-afh into tH^ 
folution, by which the volatile alkali of the fal am- 
moniac is difengaged. 
Hellot obferves, that if Cochineal, after the ufual 
pulverization, be mixed with one-fourth part of it's 
weight of pure dry cryftals of tartar, and the mix- 
ture be levigated into an impalpable powder, the 
faving of the Cochineal, both for the crimfon and 
fcarlet dye, will be about one part in four, without 
the fmalleft injury to the colour. 
COCHLEA. A very large family of fea-lhells,' 
divided by authors into three diftind genera, from 
the figure of their mouths, fome of which are cir- 
cular, others femicircular, and ibme oval. Thefe 
are expreffed by the generical names Cochlese lu- 
nares, Cochleas femilunares, and Cochlear ore de- 
preffo. 
The characters of the Cochlea ore abfciffo are 
the following: it has an univalve fhell of a broad 
figure, with a conoid bafe, and an elevated fummitj 
or fometilmes a plane and depreffed one. It is 
umbilicated, and of a pearly colour within; and 
it's mouth is of an oval figure, ibmetimes furnifhed 
with teeth, and at others deftitute of any. The 
conic figure of thefe fliells readily diftinguifhes 
them from all others. 
The apex of feveral fpecies of this genus is ele- 
vated to a confiderable height, and forms various 
fpiral turns, which are properly called fabots by the 
French, and trochi by the authors of other nations^ 
In others, which bear a greater refemblance to the 
ftiape of common fnails, the apex is lefs elevated; 
and, finally, in fome of them, the apex is quite 
depreffed. Thefe diftinflions fufficiently prove, 
that in general the elevation of the apex of ftiells 
is no genuine charafter of a genus; and, among 
the trochi, there is one fingle fpecies which is um- 
bilicated, while all the reft are otherwife. 
From the figures of thefe fliells, it will evidently 
appear, that the name Trochi, according to the com- 
mon derivation of the word, but imperfectly ex- 
preffes the feveral kinds, which are of very various 
formations. They are much better reprefented by 
the term Cochlea ore depreffo, which conveys ail 
idea of an ablblute diftinCtion that takes place in 
all of them, but in no other order of fhells what- 
ever. 
COCK. The name of the males of gallinace- 
ous birds; the diftinguifhing chara6lers of which 
are, that the feet have each four toes ; that the front 
of the head is adorned with a comb; and that the 
wattles are double, naked, and flat. 
Of all other birds, the Cock feems to have been 
firft reclaimed from the foreft, and taken under the 
protection of man, in order to fupply the accidental 
failure of the luxuries or neceffities of life. Flav- 
ing thus been longeft fubjeCt to human cultivation, 
he exhibits an amazing number of varieties, fcarcelv 
two birds of this fpecies being found to refemble 
each other exaClly in form and plumage. The tail, 
which is fo great an ornament to the generality of 
thefe birds, is entirely wanting in others. The 
toes, in animals of the poultry kind, are ufually 
four ; but in one fpecies of the Cock, v/hich abounds 
in the environs of Dorking in Surry, they amount 
to five. The feathers, which in moft of thofe ani- 
mals we are acquainted with lie lb fmooth and in 
fuch beautiful order, are in a peculiar breed all in- 
verted, and ftand contrary to their natural direc- 
tion; and there is a fpecies imported from Japan, 
which, inftead of feathers, feems to be entirely co- 
vered with hair. The above, with many other di- 
2 7-. verfities. 
