334 
C 0 I 
C 0 I 
C 0 t 
will unite and form solid bodies anew, till 
their number is so much diminished, that 
their mutual attraction is again counterba- 
lanced by the affinity of the iiquid. Hence 
the reason that evaporation occasions the 
crystallization of those bodies which are held 
in solution by these liquids. 
. 7. These different solid bodies differ ex- 
cessively from each other in their tendency 
to cohesion ; and this difference can only be 
■ascertained by experiment. Thus the ten- 
dency to cohesion, and the force of cohesion, 
in silica, is so strong, that when it lias been 
precipitated from a solution by' evaporation, 
it cannot be dissolved again in the same li- 
quid. 
This tendency to cohesion, and the con- 
sequent insolubility of the ^compound, pro- 
duce many of the most important phenome- 
na of chemistry, as they occasion the various 
precipitations and decompositions which so 
often take place when different substances 
are mixed together. See Attraction, and 
M ECHANICS. 
COHORT, cohors, in Roman antiquity, 
the name of part of the Roman legion, com- 
prehending about six hundred men. There 
were ten cohorts in a legion, the first of 
which exceeded all the rest, both in dignity 
and number of men. When the army was 
ranged in order of battle, the first cohort 
took, the right of the first line, and the rest 
followed in their natural order ; so that the 
third was in the centre of the first line of the 
legion, and the fifth on the left, the second 
between the first and third, and the fourth 
between the third and fifth: the five remain- 
ing cohorts formed a second line, in their 
natural order. 
COIF. The serjeants at law are other- 
wise called serjeants of the coif, from the 
lawn coif they wear on their heads, under 
their caps, when they are created., and al- 
ways after. 
COIN denotes all the several stamps and 
species of money in any nation. In earlier 
times, when the necessity of traffic .put men 
upon the expedient of having money ; and 
metals, on account of their firmness, clean- 
liness, and durableness, were chosen for that 
end ; each person cut his metal into pieces 
of different sizes and forms, according to the 
quantity to be given for any merchandize, 
or according to the demand of the seller, or 
the quantity . stipulated between them. It 
was usual then to go to market laden with 
jnetal, in proportion to the purchase to be 
made; and furnished with instruments for 
proportioning it, and with scales for dealing 
it out, according as occasion required. By 
degrees it was found more convenient to 
have pieces ready weighed ; and as there 
were different weights required, all those of 
the same weight were distinguished with the 
same mark or figure. At length the grow- 
ing commerce of money beginning to br 
disturbed with frauds, both in the weights and 
the matter, the public authority interposed ; 
and hence arose tiie first stamps, or impres- 
sions of money, to \Vhich succeeded the 
names of the moneyers, and at length the ef- 
figies of the prince, the date, legend, and 
other precautions to prevent the alteration 
of the specie : thus w ere coins completed, 
,ind gradually brought to their -present per- 
fection. See Coinage. 
10 
The following are Tables of the most remark- 
able Coins, both ancient and modern. 
CO O 
J o rt (S M » 'O 
p- i i « 
b0 
w 
is 
2 
"3 
bJO 
The Grecian coins, with their value and pro- 
portion. 
1% 
-1® 
m i'* 
f H- 
Hov 
cv|m 
<s,0 ' 
o 
VN 
- 
Cl 
o 
co 
01 
o 
CT 
0 
■P 
o 
o 
o 
VO 
I> 
CO 
Ol 
U O 
o 
o 
o 
o 
o 
o 
o 
CM 
co 
o 
o 
o 
o 
o 
o 
o 
o 
c 
Vi 
o 
<u I >-l+ 
h l~ 
-■5 I I H|0 
q | cn | cn 
o — 
P 
CD I wlct I CO I to I «|o< 
b h i 1 H 
oi | m | to I tn | vo 
£ | o> wr j =o | | £ 
<M I Tf | tO 
o 
O , i> 
cu ! 
-r i to | 01 I 'f | o 
Ol CO 1-- -f 1 I CO 
ov co ! to co ; to 
Of these the drachma, didrachma, See. were of 
silver ; the rest, for the most part, of brass. 
The Grecian gold coins were the stater aureus, 
worth twenty-five Attic drachms of silver ; the 
stater Cyzicenus, stater Philippicus, ar.d stater 
Alexandrinus, worth twenty-eight drachms ; 
the stater Daricus, according to Josephus, worth 
fifty Attic drachms ; and the stater Crcesius, of 
the same value. 
Ter 
10 
0 0 0 0 _L7JL, 
)OOJ 
The value of the Roman coin*. 
£• s- d. q. 
uncius 
Semilibella - - - 
2 I.ibella, cr As - 
? Sestertius - 
oooi J-K 
too 
10 
0 Quinarius 
“ Victoriatus 
4 2 'Denarius 
0 0 13 f 
0 0 3 3 \ 
0 0 7 3. 
d. 
3fj 
1 0 9 
0 12 11 
Of these the denarius, 'victoriatus, sestertius, and 
sometimes the as, were of silver, the rest of 
brass. The Roman gold coin was the aureus, 
which weighed generally double the denarius, 
the value of which, according to the 
first proportion of coinage mention- 
ed by Pliny, was worth 
According to the proportion that 
obtains among us, worth 
According to the decuple propor- 
tion, mentioned by Livy and Julius 
Pollux, worth - 
According to the proportion men- 
tioned by Tacitus, and which after- 
wards obtained, whereby the aureus 
exchanged for 25 denarii, its value is 0 16 
It must be observed, that in all these tables of 
ancient coins, silver is reckoned at five shillings, 
and gold at four pounds, the ounce. 
Modern coins, current in the four quarters of 
the earth at this day, are either made of metals, 
or they are shells and fruits. The metals are 
gold, silver, copper, tin, and lead; to which may 
be added billon, a mixture of silver and copper 
in a certain proportion. 
In Europe none are used besides gold, silver, 
copper, and billon : in some parts of the East! 
Indies they likewise use tin and lead: as to shells 
and fruits, they are the small money of several 
nations in Asia, Africa, and America. 
Coins, British. In England, the current spe- 
cies of gold were formerly the guinea, half-gui- 
nea, jacobus, laureat, angel, and rose-noble; the 
four last of which are now seldom met with 
having been mostly converted into guineas, 
chiefly during the reigns of Charles II. an " 
James II. 
The silver coins are, the crown, half-crown,! 
shilling, and sixpence: there are likewise penn 
two-penny, three-penny, and groat pieces in 
silver, but these are only for curiosity. 
The copper coins are the penny, halfpenny 
and farthing. 
Value and proportion of the English coins 
ancient and modern 
Farthing 
4 
48 
120 
240 
960 
1008 
Halfpenny 
Penny 
120 
480 
12 
30 
60 
210 
25 £ 
Shilling 
Half-crown 
2 Crown 
25 10 
4 Pound, accompt 
4J_ It Guinea 
1+ Jacobus 
23|9il34j | Carolus, or 
5 1 I . 
■— laureate. 
Tn Scotland, by the articles of the union 
it is appointed that all the coins shall be re 
duced to the English, and the same accompt 1 
be observed throughout the whole island, 
Till then, the Scotch had their pounds, shil- 
lings, -and pence, as in England •, hut their 
pound was but twenty pence English, and 
