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ter ; yet it falls fhort of accounting for that firft Cohejion of the Atoms, or primitive Corpufc'es, whereof the Corpufcles of hard Bodies are compos'd.
Sir Jfaac Newton delivers his Doctrine of Cohejion thus : ' The Particles of all hard, homogeneous Bodies which touch ' one another, cohere with a great Force ; to account for ' which, fome Philofophers have recourfc to a kind of hook-
- ed Atoms, which in effect, is nothing elfe but to beg the
' Thing in queftion. Others imagine, that the Particles of ' Bodies are connected by Reft ; ;'. e. in effect, by nothing ' at all ; and others by confpiring Motions; i. e. by a rela- ' tive reft among themfelves. For myfelf, it rather appears ' to me, that the Particles of Bodies cohere by an attraSive ' Force, whereby they tend mutually toward each other : ' which Force, in the very point of Contact, is very great ; ' at little Diftances is lefs ; a little farther diftance is quite c infenfiblc.' See Attraction.
' Now if compound Bodies be fo hard, as by Experience ' we find fome of 'em to be, and yet have a great many ' hidden Pores within 'em, and confifl of Parts only laid to- ' gether ; no doubt thofe fimple Particles which have no ' Pores within 'em, and which were never divided into Parts, ' muft be vaftly harder. See Matter.
' For fuch hard Particles gather'd into a Mafs, can't poffi- ' bly touch in more than a few Points : and therefore much ' lefs Force is requir'd to fever them than to break a folid ' Particle, whofe Parts touch throughout all their Surfaces, « without any intermediate Pores or Interlaces. But how ' fuch hard Particles, only laid togeiher, and touching only ' in a few Points, fhould come to cohere fo firmly as in fact ' we find they do, is inconceivable ; unlefs there be fome ' Caufe, whereby they are attracted and prefs'd together.
' Now, the fmallett Particles of Matter may cohere by the ' ftrongeft Attractions, and conftitute larger ; whofe attract- ' ing Force is feebler : And, again, many of thefe larger ' Particles cohering, may conftitute others ftill larger ; whofe ' attraSive Force is ftill weaker ; and fo on for fcveral Suc- ' ceffions, till the Progreffion end in the biggeft Particles, ' on which the Operations in Chymiftry, and the Colours of ' Natural Bodies do depend ; and which by cohering com- ■ pofe Bodies of a fenfible Magnitude.' See Hardness, Fluidity, and Firmness.
The different Degrees of Cohejion, conftitute Bodies of different Forms and Properties.
Thus, the fame great Author obferves, that the Particlesof Fluids which don't cohere too ftrongly, and are fmall enough to render 'em fufceptible of thofe Agitations which keep Liquors in a Fluor, arc noil eafily feparatcd and rarefied in- to Vapour, and make what the Chymifts call Volatile Sa- dies ; rarefying with an eafy heat, and again condenfing with a moderate cold. See Volatility.
Thofe whofe Particles are groffer, and fo lefs fufceptible of Agitation, or cohere by a ftrongcr Attraction, are not fepa- rable without a greater degree of Heat; and fome of 'em not without Fermentation : and thefe make what the Chymifts call Fix' d Sadies. See Fixation.
COHOBATION, in Chymiftry, a repeated Diftilla- tion of the fame Matter, with the Liquor drawn from it ; that Liquor being again and again return'd upon the Mat- ter left at the bottom. See Distillation.
The Defign of this Operation is to open the Pores, and feparate and volatilize the fpirituous Part.
Cohohation is a kind of Circulation ; only differing from it in this, that the Liquor is drawn off in Cohobatian as in common Diftillation, and thrown back again ; whereas in Circulation it rifes and falls in the fame Veflel, without ever being carried out. See Circulation.
COHORT, Cohors, among the Romans, a Body of Infan- try, confifting of five or fix hundred Men ; anfwering in mod refpeefs to our Battalion.
The Cohort was divided into three Maniples, or Compa- nies ; the Maniple into two Centuries ; and the Century in- to an hundred Men. See Manipulus, Century, t$c.
The firft Centurion in a Cohort was called <Primipilus ; and bore the Eagle, or Standard of the Legion. See Primi- pilus.
A Legion confiftcd of fix Cohorts. See Legion.
When the Army was rang'd in order of Battel, the Co- harts were difpos'd in the following manner: The firft Cohort took up the right of the firft Line, as the Companies of Grenadiers do in our Regiments ; the reft follow'd in their natural Order : fo that the third was in the Centre of the firft Line of the Legion, and the fifth on the left : the fe cond between the firft and third ; and the fourth between the third and fifth. The five remaining Cohorts form'd a fecondLine in their natural Order : Thus the fixth was be- hind the firft, and fo of the reft.
The firft, third, and fifth Cohorts were efteem'd the beft; at leaft it appears fo from the Pofts they took up, which were look'd on by the Romans as the moft important.
Marius was the firft who divided the Roman Forces into Cohorts.
( 24.7 ) c o 1
The Word properly fignifies the Area, Yard, or Spaed before the Door of a Houle.
ufc.
COIF the Badge of a Serjeant at Law; who is hence alio called Serjeant of the Coif. See Serjeant.
The Coif is of Lawn, and wore on the Head, under the Cap when they are created, and ever after.
The Ufe of the Coif was to cover the l"onfuram Clerica- lem, otherwife called, Corona Clcricalis ; becaufe the Crown of the Head was clofe Ifiav'd, and only a Border of Hair left around the lower Part, which gave it the Appearance of a Crown. See Crown, Tjenia, £?c.
COIN, or Matrice, in the Manufactory of Money, Me- dals, Counters, lie. is a piece of Steel well temper 'd, four or five Inches high, fquare at bottom, and round a-top ; whereon are engraved, Dent-wife, or En creux, with Pun- chions and other Inttruments, the feveral Figures, Marks, SSc. to be ftruck on the Monies, (gc. See Matrice.
For the manner of engraving of the Coins ; fee Encra- ving an Steel.
Coin is more generally us'd for a Piece of Metal, con- verted into Money, by the impreffing of certain Marks or Figures thereon. See Money.
Or, Coin may be defin'd, a Species of Money, ftruck with a Hammer, or Mill. See Coinage.
Hence, Coin differs from Money, as the Species does from the Genus. Money is any Matter, whether Metal, Wood, Leather, Glafs, Horn, Paper, Fruits, Shells, Kernels, &c. which have courfe as a Medium in Commerce.
Coins are a particular Branch of Monies, viz. fuch as are made of Metal, Gold, Silver, or Copper, and ftruck accord- ing to a certain Procefs, call'd Coinage.
It is obferv'd, under the Article Money, that the precife Epocha of the Invention of Money is not known ; 'tis too antient for our Annals : And if we might argue from the Neceffity and Obvioufnefs of the Thing, muft 'be nearly co- eval with the World.
Whether Coins be of equal Antiquity, may admit of foms doubt ; efpecially as molt of the antient Writers are fo fre- quent and exprefs in their mention of Leather Monies, Pa- per Monies, wocden Monies, i£c. Some, however, maugre all this, are of opinion that the firft Monies were of Me- tal : the Reafons they give, are the Firmnefs, Neatnefs, Cleanlinels, Durablencfs, and Univerfality of Metals ; which, however, do rather conclude, they ought to have been fo, than that they actually were fo.
In effect, the very Commodities themfelves were the firft Monies, i. e. had courfe for one another by way of exchange 5 and it was the difficulty of cutting, or dividing certain Com- modities, and the impoffibility of doing it without great Lofs, that firft put 'em on the Expedient of a general Me- dium. See Trucking.
Indeed, thus much may be faid in behalf of Coins, that, on this view, 'twas natural for 'em to have their firft recourfe to Metals ; 'as being almoit the oniy things whofe Goodnefs, and as it were Integrity, is not diminifh'd by Partition; be- fides the Advantages above exprefs'd, and the Convenien- ces of melting, and returning 'em again into a Mafs of any fize or weight. See Exchange.
'Twasprobably, then, this Property of Metals which firft accuftom'd People, who traffick'd together, to account 'em in lieu of Quantities of other Merchandifes in their Exchanges - and at length to fubftitute 'em wholly in their ftead : and thus arofe Money: As it was theirothcr Property to preferve any Mark or Impreffion a long time, which confirm 'd 'em in the Right ; and thus was the firft rife of Coins.
In the firft Ages, each Perfon 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 ftipulated between them : To this end they went to Market, loaden with Metal, in propor- tion to the Purchafe to be made, and furnifti'd with Inftru- ments for portioning it, with Scales for dealino it out, ac- cording as occafion requir'd.
By degrees it was found more commodious to have Pieces ready weigh'd ; and as there were different Weights re- quir'd, according to the Value of the different Wares, all thofe of the fame Weight began to be dittinguifh'd with the fame Mark, or Figure : Thus were Coins carried one ftep further.
At length, the growing Commerce of Money beginning to be difturb'd with Frauds, both in the Weights and the Mat- ter, the publick Authority interpos'd ; and hence the firft Stamps or Impreflions of Money ; to which fucceeded the Names of the Moniers ; and at length the Effigies of the Prince, the Date, Legend, and other Precautions to prevent the Alteration of the Species : And thus were Coins com- pleated. See Commerce.
On the Foot whereon Money now ftand% 'tis divided into real, or effective Money ; and imaginary Money, or Money of Accompt.
Jmagi-
