C A It 
CAR 
CAR 
30.5 
v'lot conceals himself, in some crevice if 
there is one ; but if not, the larger carabus 
renews lire attack, takes his prisoner by the 
head and tears it off, 
CARACOL, in architecture, denotes a 
stair-case in a helix or spiral form. 
CAR ACT, Carat, or Carrat, the name 
of that weight which expresses the degree of 
fineness that gold is of. The mint-master, 
or custom, lias fixed the purity of gold at 
24 caracts; though it is not possible so to 
purify and refine that metal, but it will want 
still about one fourth part of a caract in ab- 
solute purity and perfection. The caract is 
divided into tt> To > yV These degrees 
serve to distinguish the greater or lesser 
'quantity ' of alloy therein contained : for in- 
stance, gold of 22 caracts, is that which has 
two parts of silver, or of -any other metal, 
and 22 of fine gold. 
It is also a certain weight which goldsmiths 
and jewellers use with which to weigh pre- 
cious stones and pearls. This caract weighs 
four grains, but something lighter than the 
grains of other weights. Each of these grains 
is subdivided into -i, i. i, T 1 7 -, &c. 
CARAGllOUTH, in commerce, a silver 
c-oin of the empire, weighing nine drachms. 
It goes at Constantinople for 120 aspers. 
CARBON, or the radical of carbonic acid, 
has not, unless the diamond is admitted as 
such, been yet obtained in a separate state: 
charcoal, which was once so esteemed, ap- 
pearing to be a compound substance. Nor 
is it ever found united with caloric, in a 
gaseous state, unaccompanied by some third 
principle. Its taste, smell, and colour are 
unknown. It is infusible and indissoluble 
by caloric, and is hence esteemed the most 
refractory substance in nature. It has no 
evident attraction for nitrogen alone, but 
combines with it by the intervention of oilier 
principles. With hydrogen it has a strong 
affinity, uniting and forming a gas termed 
carbonated hydrogen ; hydrogen gas having 
the power of holding it in solution. 
The diamond, which exceeds all other 
gems in hardness, density, and refraction of 
the rays of light, crystallizes in two tetra- 
hedral and trihedral pyramids, united base 
to base, or in hexahedral prisms terminating 
in trihedral summits, or in irregular poly- 
hedral grains. At a very high temperature it 
burns, becomes black and opaque, and is - 
converted into gas. Sp. gr. about 3,5. 
Newton conjectured the diamond to be a 
combustible body. Guyton, in 1785, infer- 
red its similarity to charcoal, from its leaving . 
an effervescent alkali, after combustion in 
fused nitre. Lavoisier found that on burn- 
ing it in closed vessels, it yielded carbonic 
acid. This has also been proved by Mr. 
Tennant, who performed the combustion in 
a crucible of gold. Bertbollet considered it 
as crystallized charcoal. 
Since this, Guyton, having burnt the dia- 
mond in oxygen gas, by the solar rays, and 
thereby having obtained carbonic acid with- 
out residue, presumed that he had ascer- 
tained the diamond to be pure carbon, or 
the pure combustible matter of the carbonic 
genus, yielding the pure aciditiable basis of 
the carbonic acid. He found its combustion 
required a much higher temperature than 
charcoal ; but this, he observes, takes place 
Yon. I. 
with other aciditiable bases, their first degrees 
ot oxydation being difficultly produced, al- 
though their subsequent acidification is easy. 
It also required more oxygen for its com- 
plete combustion than charcoal ; one part of 
diamond absorbing four of oxygen, and pro- 
ducing live of carbonic acid; this he remarks 
is not to be wondered at, since being pure 
carbon, it contains none of the oxygen prin- 
ciple, and therefore demands more. In 
proportion therefore as substances contain 
pure combustible matter, will, in fact, be the 
difficulty of their combustion, their first de- 
grees of oxygenation proceeding so slowly. 
Thus he accounts for plumbago, or black 
lead, which is a carbonic combustible, richer 
in combustible matter than charcoal itself, 
not burning, but at a very high degree of 
temperature : and thus he accounts for the 
incombustibility of anthracolite, Kilkenny 
coal, the brilliant charcoal of certain vege- 
tables, &c. The diamond is therefore to be 
considered as pure carbon ; plumbago, car- 
bon oxygenized in the first degree ; charcoal, 
an oxyd of the second, obtained from various 
substances in the animal, vegetable, and mi- 
neral kingdoms, generally by volatilizing 
their other constituent parts. When obtain- 
ed in a state of purity, it resists the strongest 
heat in closed vessels. It decomposes sul- 
phuric acid, from its affinity with oxygen 
exceeding that of sulphur. It decomposes 
nitric acid with great rapidity ; and if the 
charcoal is first powdered, and the acid 
strong, and allowed to run down the side of 
the vessel, to mix with the charcoal, it burns 
with rapidity, with a beautiful flame, throw- 
ing up the powder so as to resemble a beau- 
tiful tire-work. With nitrate of pot-ash, it 
detonates in a hot crucible, leaving a fixed 
alkali behind. It is dissolved by the alkalies, 
and by the sulphurets of alkali, both in the 
dry and moist way. It does not unite with 
metals, but restores their oxyds to a metallic 
state. 
Charcoal possesses the power of absorbing 
several gases, which thus condensed retain 
their properties, and even exert them in 
some instances more powerfully. It decom- 
poses water at tire common temperature, car- 
bonic acid and carbonated hydrogen being se- 
parated. If burnt in contact with common air, 
its acidifiable base attracts oxygen, and this 
peculiar acid is formed, which, with a certain 
proportion of caloric, assumes a gaseous 
form. If burnt in oxygen gas, its peculiar 
acid is plentifully formed, the charcoal burn- 
ing with considerably increased rapidity, and 
if the lighter charcoal made from bark is 
used, a very brilliant effect is produced from 
the numerous vivid corruscating sparks. 
CARBONATES, are neutral salts, com- 
posed of the carbonic acid, and certain bases: 
thus carbonate of ammonia, or mild volatile 
alkali, consists of carbonic acid and pure or 
caustic ammonia. Owing to the weakness 
of this acid, the characters of their bases arc 
generally most predominant. 
The carbonates are not acted on by light, 
oxygen, or nitrogen ; nor do they deliquesce 
with the moisture of the atmosphere. Al- 
though charcoal decomposes the phosphoric 
acid alone, the carbonates are decomposed 
by phosphorus ; this difference arises from 
the attraction which the phosphoric acid ex- 
ercises on the base of the carbonate ; from 
similar causes the effects of different com- 
bustible bodies on them vary much. Ail 
the other acids have a greater attraction for 
the earthy and alkaline bases than the car- 
bonic ; that acid being disengaged from the 
carbonates by their addition. So feeble is 
this acid, that it is separated from most of it%. 
bases by heat only. 
CARBUNCLE, in natural history, a very 
elegant gem, the colour of which is deep red, 
with an admixture of scarlet. See Garnet. 
Carbuncle, ' or Anthrax, in surgery, 
an inflammation which arises, with a vesicle 
or blister, almost like those produced by 
burning. This inflammation, tor the most 
part, terminates in a sphaceLus, and petrifies 
the subjacent parts down to the bone, they 
becoming as black as a coal. A carbuncle 
always breaks out very speedily, even in the 
space of an hour or two, attended with heat 
and pain: as soon' as it is opened, it dischar- 
ges a livid sanies, or sometimes a limpid wa- 
ter: it is black within, which is a sign that 
the sphacelus has seized the subjacent parts, 
and is making its progress : but the pu- 
trid flesh in those who recover, suppurates, 
and parts from the sound. The size of these 
pestilential blisters is various, more or less ; 
as is also their number in the patient ; for 
there is no part of the body which they do 
not infest, and they generally appear in com- 
pany with buboes. 
Those carbuncles which arise in the face, 
neck, breast, or armpits, are observed to be 
of the worst kind, for they generally kill the 
patient. 
In the external treatment, some of the 
modern physicians use only scarification in 
this case, with very good success ; others 
open the eruptions with a pair of scissars, 
and having discharged the matter, frequently 
wash the carbuncle with sp. vin. camph., 
or sp. vin. in which has been digested 
a little theriaca : they afterwards apply a 
maturating cataplasm, which is to be conti- 
nued till the carbuncle separates from the 
sound parts ; then they cut it out all at 
once. 
Carbuncle, in heraldry, a charge or 
bearing consisting of eight radii, four where- 
of make a common cross, and the other four 
a saltier. 
CARCASS, a composition of combusti- 
bles. Carcasses are of two sorts, oblong 
and round : the uncertain weight of the first 
sort has almost rendered them useless. They 
are prepared in the following 'manner : Boil 
12 or 1 Alb. of pitch in a glazed earthen pot ; 
mix with that 31b. of tallow, 30lb. of powder, 
61b. of saltpetre, and as many stopins as can 
be put in. Before the composition is cold, 
the carcass must be filled ; to do which, 
smear your hands with oil or tallow, and fill 
the carcass one-third fill l with the above com- 
position; then put in loaded pieces of gnu 
or pistol barrels, loaded grenades, and fill 
the intervals with composition; cover the 
whole over with coarse cloth, well sewed to- 
gether, keeping it in a round form. T hen 
put it into the carcass, having a hollow top 
and bottom, with bars running between 
them to hold them together, and composed 
of four slips of iron jointed at top, and fixed 
at the bottom, at equal distances, to a piece 
