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Thus, Dr. Keil fuppofes the Ocean to be one quarter ot a Mile deep, communilus loch, q. d. at a Medium, or tak- ing one place with another. . ,
Communibus Amis, has the fame Import with regard to Tears, that Communihus locis has with regard to places.
Thus, Mr. <Derbam obferves, that the Depth ot Kara, communikts anms, i. e. one Year with another, were it to ftagnate on the Earth, would amount to, at Townly mLan- ctjkre, Mi Inches ; at Upninfter in Ejfex 19} ; MLuncK
9»j ; at Tlfa «i 5 »n d at <Par ' 5 t0 '» V 1 »k r
COMMUNICATING, in Theology, the A3 of receiv- ing the Sacrament of the Eucharift. See Eucharist.
Thofe of the Reform' d and of the Greek Churches com- municate under both Kinds ; thofe of the Romijh only un- der one. J , . „ T . C -
From the fecond Book oiX'ertullian to his Wire, it ap- pears, that antiently they communicated falling. S.Atl- guftm fays cxprefly, that in Tome Churches, in his lime, they communicate A every Day. .
Among the Greeks, M. Fleury obferves, the Laity Kill communicate every Sunday ; thofe who omit it three Sundays together are excommunicated.
The Oriental Communicants receive the Species ot Wine by a Spoon ; antiently, they fuck'd it thro' a Pipe, as has been obferv'd by Seat. Rbenanus on Tertullian.
COMMUNICATION, the Aa of imparting a thing to another, or making him a Sharer with us therein.
Thus God is fiid to communicate his Grace to us by means of his Sacraments. The Ufe of Speech is for the communicating of our Ideas and Sentiments to each other.
Philofophers are at a Lofs as to the manner of the Com- munication, or Intercourfe between Soul and Body. See Soul, Cause, iSc.
Communication is alfo ufed for the Conneaion ot one thing with another ; or the Paffage from one Place to ano- ther.
Antiently, it was frequent to have fubterraneous Commu- nications between one Place and another. Such a Gallery makes a Communication between fuch.two Apartments.
Lines of Communication, in War, call'd alfo limply lines; are Ditches fix or feven Foot deep, and 12 broad, made between one Fort, or Work, and another ; in order for a Paffage between one Quarter and another ; efpecially in Sieges. See Line, &c.
Communication of Idioms,. in Theology, the Communi- cation of the Attributes of one Nature in Jefus Chrift to that of the other. .
The Communication of Idioms, is rounded on the Unity ot two Perfons in Jefus Chrift : By this Communication of Idioms it is, that we fay, God fuffer'd.died, ££c. which is ftriaiy un- derftood of the Human Nature ; and fignifies, that God fuf- fer'd in his Humanity, that he died as to his Human Na- ture. For the Denominations which fignify Natures, or Pro- perties of Nature, the Schoolmen tell us, are Denominations of Suppofitums, or Perfons, and are to be attributed to 'em : Thus, the two Natures only fubfifting in Jefus Chrift by the fole Perfon of the Word, to this Perfon muft be attributed the Denominations of both Natures, and of their Properties. But we may not by Communication of Idioms attribute to Jefus Chrift what would fuppofe him not to be God; fince that would deftroy the Hypoftatical Union, which is the Foundation of the Communication of Idioms. Thus, we may not fay that Jefus Chrift is mere Man ; that he is fal- lible, iSc. . .
The Lutherans carry the Communication 0] Idioms lo tar, as to fay, that Jefus Chrift is not only in his Divine Na- ture, and by reafon of his Divine Perfon, but alfo really and properly in his Humanity, Immortal, Immenfe, \3c.
Communication of Motion, the Aaion of a moving Bo- dy, whereby a Body at reft is put in Motion, or a Body al- ready in Motion accelerated. See Motion.
F. Mallebranch looks on the Communication of Motion as fomething Metaphyfical ; i. e. as not neceflarily arifing from any phyfical Principles, or any Properties of Bodies, but flowing from the immediate Agency of God : there being, according to him, no more Conneaion, or Dependence be- tween the Motion or Reft of one Body, and that of another, than between the Form, Colour, Magnitude, He. of one Body and thofe of another. The Motion of one Body, therefore, on his Principle, is not any phyfical Caufe of that of ano- ther. See Cause.
Laws of the Communication of Motion.
Aaion, and Reaaion, Sir Ifaac Newton demonftrates, are equal and oppofite 5 fo that one Body {hiking againft ano- ther and thereby occafioning a Change in its Motion, does it feif undergo the very fame Change in its own Motion, the contrary way.
Hence, a moving Body ftriking direaiy againft another at reft, the one lofes juft as much of its Motion as it com- municates to the other ; and they will proceed with the fame Velocity as if grown into one Mafs.
If, thetefore, the Body in Motion be triple that at reft againft which it ftrikes, it will lofe a fourth Part of its M . tion; and whereas, before, it would have run over (v. » 1 j Line of 20 Foot, in a given time, it will now only run'over 18 ; i. e. it will lofe a fourth part of its Velocity.
If the moving Body ftrike on another already in Motion the firft will augment the Velocity of the latter ; but will lofe lefs of its own Motion, than had the latter been abib- lutely at reft.
Thus, v.g. if a Body in Motion be triple of another at Reft, and ftrike againft it with 52 degrees of Motion ; i t will communicate eight degrees of its Motion to the other and retain 24 to it felf. If the other Body had already four degrees of Motion, the firft would only communicate five, and retain 27 : fince thofe five were fufficient, in regard of the Inequality of the Bodies, to make 'em proceed with equal Velocity.
After the fame manner may the other Laws of Communi- cation of Motion in Bodies perfeaiy hard, and void of all Elafticity, be determin'd. But all hard Bodies that we know of have an elaftick Power ; and in elaftick Bodies, the Laws are different, and much more intricate. See Elasti- city ; and the Laws of TcrcvJJion in elaftick "Bodies, fee under Percussion.
If a Body, when moved by another, happen to decline out of the way, fo as to leave a free Paffage to the Body whereby it was moved ; yet, that will only proceed with the Velocity which it had after its Communication to the other, not with that it had before : It being a Rule, that every thing endeavours to perfevere; not in the State where- in it was formerly, but in that wherein it is at that Junc- ture : therefore, a Body which has already loft part of its Motion, by its meeting with another ; may lofe ftill more ' by a fecond and a third ; fo as at length to become per- feaiy quiefcent.
Hence, ift, if two unequal homogeneous Bodies move in a right Line with the fame Velocity, the greater muft per- fevere in Motion longer than the fmaller : for the Motions of Bodies are as their Maffes ; but each communicates of its Motion to the circumjacent Bodies which touch its Surface, in proportion to the Magnitude of its Surface ; the larger Body, therefore, tho it has more Surface than the fmaller, yet having lefs, in proportion to its Mafs or Quantity of Matter, than the fmaller, will lofe a lefs Portion of its Mo- tion every Moment than the fmaller.
Suppofe, e. g. a Cube, A, to be 2 Foot every way, and another, B, one Foot : the Surfaces here will be as 4 to 1, but their Maffes as 8 to 1. If therefore thofe Bodies move with the fame Velocity, the Cube A will have 8 times as much Motion as the Cube B (fhe Quantity of Motion be- ing ever as the Quantity of Matter). That each of 'em, therefore, may become quiefcent at the fame time, the Cube A muft lofe 8 times as much Motion every Moment as the Cube B : But that is impoflible, becaufe as their Sur- faces are to each other as 4 to 1 ; the Bodies againft which they ftrike, will only be as 4 to 1 : Therefore, when the Cube B is become perfeaiy quiefcent, A will have half its Motion.
Hence, 2dly, we fee the Reafon why any long Body, as a Dart, thrown lengthwife, continues its Motion longer than when thrown tranfverfly : it meeting fewer Bodies in the way to communicate its Motion to in the one Cafe than in the other.
Hence alfo, jdly, if a Body be moved almoft wholly within it felf, fo as to communicate little of its Motion to the ambient Bodies, it muft continue its Motion a long time. Thus, a fmooth brafs Ball of half a foot Diameter, fup- ported on a (lender fmooth Axis, with a very weak impulfe, is found to revolve, for the Space of three or four Hours. See Resistance, Z$c.
COMMUNION, in Theology, an uniform Belief in fe- veral Perfons ; whereby they are united under one Head, in one Church.
In this Senfe, the Lutherans, Calmnifts, ike. are laid to have been cut off from rhe Romijh Communion.
This is the primitive ufe of the Word Communion, as ap- pears from the Canons of the Council of Elvira.
Communion is alfo ufed for the Aa of communicating in, or participating of the Sacrament of the Eucharift. See Communicating*
The fourth Council of the Lateran, dectees, that each Believer fhall receive the Communion, at leaft, at Eaft er } which feems to import a tacit Defire that they fhould do it oftner ; as, in effea, they did do it much oftner in the pri- mitive Days. Gratian, and the Mafter of the Sentences, prefcribe it as a Rule for the Laity, to Communicate three times a Year, at Eafter, PVhitfintide, and Chriftmas. B ut ' in the XHIth Century, the Praaice was gor on foot, never to approach the Eucharift except at Eafter ; and the Coun- cil thought fit to enjoin it then by a Law, left their CoW- nefs and Remiflhefs fhould go farther ftill.
