Imatges de pàgina
PDF
EPUB

Earth

effect of

causes.

required, that the tides may have their full motion. A tide of lefs motion may be in fuch an extent of fea as the Cafpian.

In the last place, how does the theory of tides account for the regular peculiarity of the flux and reflux of the Atlantic, different from all other tides; while at Bathsha in the kingdom of Tunquin, there never is more than one tide in 24 hours; and fome days, no tide? --- For my part, I refolve the whole into the immediate power of the Deity. This power is gravity, attraction, repulfe. The inactivity of matter requires the conftancy and univerfality of divine power to fupport the material universe, and move it as occafion requires; that is, as infinite wisdom sees most conducive to the benefit of his creation.

Men of fine imagination may make a wonquakes the derful difplay of mathematical learning in immaterial accounts of gravity, etc. combined with the principles of mechanifm; and electricity, which is called the immediate officer of God Almighty; but the truth is, a conftant repetition of divine acts in regular and irregular motions of the earth and the feas. The finger of God moves the land and the waters.

In the cafe of earthquakes, as electricity, or aerial power, is infufficient to produce them, in my opinion, for two reafons before given; to wit, that the electrical Atroke is ever fingle and momentary, but the vibrations

of

of the earth, in a quake, are often 3 and 4 minutes, and have held to 7 minutes and that, befides the fwelling and trembling of the earth, it has fo opened at those times, as to swallow not only houses and people, but even mountains, and to fend forth great rivers and vaft waters. And, as fubterranean fire and vapor, I think, can never do fuch work, for many reasons that may be offered, we muft, I think, afcribe the earthquakes to the immediate impreffion of divine power; by which a city is tumbled into ruins in three or four minutes, in the fad manner Lisbon was destroyed the first of November, 1755. or, the water of the great abyfs is with fuch violence moved, that it shakes the arches of the earth, and where infinite wisdom directs, is enabled by Almighty Power to open the globe with tremendous noises, and pour forth vaft torrents of water, to cover a land where once a flourishing city has ftood. The electric stroke cannot be more dreadful than fuch exertion of omnipotence. The immediate action of the Deity, to destroy, must be as efficacious furely as any fubordinate agent or caufe: and it must be more terrible to the mind, as there can be no fuppofition of accident in ruin this way: but we fee as it were the almighty arm, exerting an irresistible force, that could in the fame few moments N 2 that

An account of mufcular

and that it

that a large town and its inhabitants are destroyed, shake the whole world into one dreadful ruin, or feparate it into nothing. To my apprehenfion, the aerial power of electricity is not fo fearfully ftriking, as the Creator's appearing, on the fpot, to Shake terribly the earth: and if we confider, that it is on account of fin, that God refigns his omnipotence to his wrath, and commands his whole difpleasure to arife, must not this account of an earthquake have the greatest tendency to reform the manners of the furviving people?

As to muscular motion, if it be rightly confidered, it appears very plainly to proceed motion; from a living force, impreffed ab extra; that is caufed by mechanifm does not act as cause in this affair; a continued but the divine power acts in the cafe, as it Deity. does in many different places of the human body at once, and with inexpreffible variety.

act of the

Various are the accounts that learned men have given of muscular motion, and ingenious are their reasonings on the fubject: but they are not fatisfactory, nor do they at all explain the thing, and account for it. What is a muscle?

It is to be fure a bundle of small blood veffels, confifting of arteries and their returning veins, laid one upon another in their parallel plates, running thro' the whole length of the muscle; and at small intervals, thefe blood

I

blood veffels, or longitudinal, red, and fleshy fibres, are contorted and bound about with fmall, tranfverfe, and fpiral ramifications and twinings of the nerves. This is a muscle: it has two ends, or tendons, faftened to two bones, one of which is fixed, and the other moveable; and by the contraction of the muscle, the moveable bone is drawn upon its fulcrum towards a fixed point. This is indifputable; and it is likewife certain, that the muscles are to be diftinguished into those of voluntary, and those of natural or neceffary motion: that the voluntary muscles have antagonists, which act alternately in a contrary direction, that is, are contracted by the command of the will, while the others are ftretched, and again are extended, while the others are contracted: but the neceffary mufcles have contracting and extending powers within themselves, and need no antagonists.

This being the true state of the muscles, the question is, what causes that elasticity, fpring, or power of contraction and restoration, which their nervous coats and fibres have, to recover themselves against a given weight or force that ftretches them? The reply is, that many unanswerable reasons can be given to prove, that this contractive reftitutive force does not depend on the mixture, effervefcence, or rarefaction of any fluids, humours,

N 3

humours, or liquors within the body; and there is one convincing experiment that

fhews it.

Lay open the thorax of a dog, (as I have often done) and take a distinct view of that famous muscle, the heart, in its curious and wonderful motion, while the animal is still alive. In diafole, the muscle is very red and florid, foft and yielding to the touch, and thro' it the vital fluid glows and fhines; it appears in this ftate fully replenished and diftended with blood: but in fyftole, as foon as it begins to contract, and the blood rushes out by the compreffion of the contracting fibres, the heart lofes its florid colour, and becomes pale and livid, compact and folid, and evinces that, during this ftate of it, the muf cle contracts inwardly into its own dense subftance, and takes up lefs fpace than before, till it returns to its diaftole: then the blood which flowed from it with velocity, during Systole thro' the coronary veins into the auricles, rufhes back into it thro' the coronary ar teries, reftores the glowing florid colour, and inflates the muscle, in order to ftrain the nerves for the next contraction. It is plain from hence, that the heart has lefs blood and fluid in time of contraction, and that the contraction is not caused by the addition of another fluid from the nerves, as the learned have afferted.

[merged small][ocr errors]
« AnteriorContinua »