in any of the courts at Westminster, under the seal of each court; which exemplifications may be given in evidence to a jury. It is held that nothing but matter of record ought to be exemplified.

EXERCISE, among physicians, such an agitation of the body as produces salutary effects in the animal economy. Exercise may be said to be either active or passive. The active is walking, hunting, dancing, playing at bowls and the like; as also speaking, and other labour of the body and mind; the passive is riding in a coach, on horseback, or in any other manner. Exercise may be continued to a beginning of weariness, and ought to be used before dinner, in a pure light air; for which reason, journies and going into the country contribute greatly to preserve and re-establish health.

EXERCISE, in military affairs, is the ranging a body of soldiers in form of battle, and making them perform the several motions and military evolutions with different management of their arms, in order to make them expert therein.

Exercise is the first part of the military art, and from it the greatest advantage may be expected, in the expertness with which men become capable of loading and firing, and their learning and attention to act in conformity with those around them. It is not from numbers, or from inconsiderate valour, that victory can rationally be hoped for. In battle the triumph is usually derived from a knowledge of arms, and a strict attention to discipline.

EXERCISE of the infantry, includes the use of the firelock and practice of the manœuvres for regiments of foot, according to regulations used by authority. The beauty of all exercise and marching consists in seeing a soldier carry his arms well, keep his firelock steady, and the whole body without constraint. Every motion should be performed with life, and with the greatest regard to exactness, and in order to these, a regiment should never be under arms longer than two hours at a time.

EXERCISE of the cavalry, is of two sorts, viz. on horseback and on foot. The officers commanding squadrons must be careful to form with great celerity, and preserve just order and distances. The men must keep a steady seat upon their horses, and have their stirrups of a fit length.

EXERCISE of the artillery,,is the method of teaching the regiments of artillery the use and practice of all the various machines of war, viz. Exercise of the light field

pieces teaches the men to load, ram, and sponge the guns well; to elevate them according to the distance, by the quadrant and screw; to judge of distances and elevations without the quadrant; how to use the port-fire, match, and tubes for quick firing; how to fix the drag-ropes, and use them in advancing, retreating, and wheeling with the field-pieces; how to fix and unfix the trail of the carriage on the limbers, and how to fix and unfix the boxes for grapeshot on the carriages of each piece.

EXERCISE of the garrison and battering artillery, is to teach the men how to load, ram, and sponge; how to handle the handspikes in elevating and depressing the metal to given distances, and for ricochet; how to adjust the coins, and work the gun to its proper place; and how to point and fire with exactness, &c.

EXERCISE for the mortar, is of two different sorts, viz. with powder and shells unloaded, and with powder and shells loaded; each of which is to teach the men their duty, and to make them handy in using the implements for loading, pointing, traversing, and firing, &c.

EXERCISE of the howitzer, differs but little from the mortar, except that it is liable to various elevations; whereas that of the mortar is fixed to an angle of 45"; but the men should be taught the method of ricochet-firing, and how to practice with grape-shot; each method requiring a particular degree of elevation.

EXERCISES are also understood of what young gentlemen or cadets learn in the military academies and riding-schools; such as fencing, dancing, riding, the manual exercise, &c. The late establishment at High Wycomb is calculated to render young officers perfectly competent to all the duties of military service, provided they have been previously instructed in the first rudiments. Officers are there taught and exercised in the higher branches of tactics and man

œuvres.

EXERGUM, among antiquarians, a little space around or without the figures of a medal, left for the inscription, cypher, device, date, &c.

EXHALATION, a general term for all the effluvia or steams raised from the surface of the earth in form of vapour. Some distinguish exhalations from vapours, expressing by the former all steams emitted from solid bodies, and by the latter the steams raised from water and other fluids.

EXHAUSTED receiver, a glass, or other

vessel, out of which the air hath been drawn by means of the air-pump. See PNEUMATICS.

EXHAUSTION, in mathematics, a method in frequent use among the ancient mathematicians, as Euclid, Archimedes, &c. that proves the equality of two magnitudes, by a deduction ad absurdum, in supposing that, if one be greater or less than the other, there would follow an absurdity.

This is founded upon what Euclid saith in his tenth book, viz. that those quantities, whose difference is less than any assignable one, are equal. For if they were unequal, be the difference never so small, yet, it may be so multiplied, as to become greater than either of them: if not so, then it is really nothing. This he assumes in the proof of the 1st proposition of book 10, which is, that if from the greater of two quantities, you take more than its half, and from the remainder more than its half, and so continually, there win, at length, remain a quantity less than either of those proposed.

On this foundation they demonstrate, that if a regular polygon of infinite sides be inscribed in, or circumscribed about a circle; the space, that is the difference between the circle and the polygon, will, by degrees, be quite exhausted, and the circle be equal to the polygon.

EXHIBITION, a benefaction settled for the benefit of scholars in the universities, that are not on the foundation. EXIGENT, in law, a writ or part of the process of outlawry on civil actions.

EXISTENCE, that whereby any thing has an actual essence, or is said to be. Mr. Locke says, "that we arrive at the knowledge of our own existence by intuition; of the existence of God by demonstration; and of other things by sensation. As for our own existence," continues that great philosopher, "we perceive it so plainly that it neither needs, nor is capable of any proof. I think, I reason, I feel pleasure and pain; can any of these be more evident to me than my own existence? If I doubt of all other things, that very doubt makes me perceive my own existence, and will not suffer me to doubt it. If I know I doubt, I have as certain a perception of the thing doubting, as of that thought which I call doubt: experience then convinces as that we have an intuitive knowledge of our own existence."

From the knowledge of our own existence, Mr. Locke deduces his demonstration of the existence of a God.

It has been a subject of great dispute whether external bodies have any existence but in the mind, that is, whether they really exist, or exist in idea only: the former opinion is supported by Mr. Locke, and the latter by Dr. Berkeley. "The knowledge of the existence of other things, or things without the mind, we have only by sensation; for there being no necessary connection of real existence with any idea a man hath in his memory, nor of any other existence but that of God, with the existence of any par ticular man; no particular man can know the existence of any other being, but only, when, by operating upon him, it makes itself be perceived by him. The having the idea of any thing in our mind no more proves the existence of that thing than the picture of a man evidences his being in the world, or the visions of a dream make a true history. It is, therefore, the actual receiving of ideas from without that gives us notice of the existence of other things, and makes us know that something does exist at that time without us which causes that idea in us, though perhaps we neither know nor consider how it does it. This notice, which we have by our senses, of the existence of things without us, though it be not altogether so certain as intuition and demonstration, yet deserves the name of knowledge, if we persuade ourselves that our faculties act and inform us right concerning the existence of those objects that affect them: but besides the assurance we have from our senses themselves, that they do not err in the information they give us of the existence of things without us,we have other concurrent reasons; as, first, it is plain these perceptions are produced in us by external causes affecting our senses, because those that want the organs of any sense never can have the ideas belonging to that sense produced in their minds. Secondly, because we find sometimes that we cannot avoid the having those ideas produced in our minds. When my eyes are shut I can, at pleasure, recal to my mind the ideas of light, or the sun, which former sensations had lodged in my memory; but if I turn my eyes towards the sun I cannot avoid the ideas which the light or the sun then produces in me; which shews a manifest difference between those ideas laid up in the memory, and such as force themselves upon us, and we cannot avoid having; besides, there is nobody who doth not perceive the difference in himself between actually looking on the sun and contemplat

ing the idea he has of it in his memory; and therefore he hath certain knowledge that they are not both memory or fancy. Thirdly, add to this, that many ideas are produced in us with pain, which we afterwards remember without the least offence: thus, the pain of heat or cold, when the idea of it is revived in our minds, give us no disturbance, which, when felt, was very troublesome; and we remember the pain of hunger, thirst, head-ach, &c. without any pain at all, which would either never disturb us, or else constantly do it, as often as we thought of it, were there no more but ideas floating in our minds, and appearances entertaining our fancies, without the real existence of things affecting us from abroad. Fourthly, our senses, in many cases, bear witness to the truth of each others report concerning the existence of sensible things without us: he that doubts when he sees a fire, whether it be real, may, if he pleases, feel it too, and by the exquisite pain may be convinced that it is not a bare idea, or phantom."

Dr. Berkeley, on the other hand, contends that external bodies have no existence but in the mind perceiving them, or that they exist no longer than they are perceived: his principal arguments, which several others, as well as himself, esteem a demonstration of this system, are as follow: "That neither our thoughts, passions, or ideas formed by the imagination, exist without the mind is allowed; and that the various sensations impressed on the mind, whatever objects they compose,cannot exist otherwise than in a mind perceiving them, is equally evident. This appears from the meaning of the term exist, when applied to sensible things: thus, the table I write on exists, i. e. I see and feel it; and were I out of my study I should say it existed, i. e. that were I in my study I should see and feel it as before. There was an odour, i.e. I smelt it, &c; but the existence of unthinking beings without any relation to their being perceived is unintelligible: their esse is percipi." Then to shew that the notion of bodies is grounded on the doctrine of abstract ideas," What," he asks," are light and colours, heat and cold, extension and figure, in a word, the things we see and feel, but so many sensations, notions, ideas, or impressions on the sense; and is it possible to separate, even in thought, any of these from perception? The several bodies then that compose the frame of the world have not any subsistence without a mind; their

esse is to be perceived or known; and if they are not perceived by me, nor by any other thinking being, they have no shadow of existence at all: the things we perceive are colour, figure, motion, &c. that is, the ideas of those things; but has an idea any existence out of the mind? To have an idea is the same thing as to perceive; that, therefore, wherein colour, figure, &c. exist, must perceive them. It is evident, therefore, that there can be no unthinking substance, or substratum of those ideas. But you may argue, if the ideas themselves do not exist without the mind, there may be things like them, whereof they are copies or resemblances, which exist without the mind. It is answered, an idea can be like nothing but an idea, a colour or figure can be nothing else but another colour or figure. It may be farther asked, whether those supposed original or external things, whereof our ideas are the pictures, be themselves perceivable or not? If they be not, I appeal to any one whether it be sense to say a colour is like somewhat which is invisible, hard or soft, like somewhat untangible, &c. Some distinguish between primary and secondary qualities, the former, viz. extension, solidity, figure, motion, rest, and number, have a real existence out of the mind; for the latter, under which come all other sensible qualities, as colours, sounds, tastes, &c. they allow the ideas we have of them are not resemblances of any thing without the mind, or unperceived, but depend on the size, texture, motion, &c. of the minute particles of matter. Now it is certain that those primary qualities are inseparably unit. ed with the other secondary ones, and cannot even in thought be abstracted from them, and therefore must only exist in the mind. Again, great or small, swift or slow, are allowed to exist no where without the mind, being merely relative, and changing as the frame or position of the organ changes: the extension, therefore, that exists without the mind is neither great nor small, the motion neither swift nor slow, i. e. they are nothing. That number is a creature of the mind is plain, (even though the other qualities were allowed to exist) from this, that the same thing bears a dif ferent denomination of number as the mind views it with different respects: thus, the same extension is 1, 3, or 36, as the mind considers it, with reference to a yard, a foot, or an inch.

"In effect, after the same manner, as the modern philosophers prove colours, tastes