ed energy of the powers of natural life. This vivifying plenum, occupying and organifing every par ticle and interftice in our compofition, can dif charge it's whole nifus according to the pathic intimation and direction of any nerve or nerves, as inftantly as electricity does through the substance of the body that receives the fhock.

When you confider the rarifying and expanfive force of this element, which is capable in an inftant of time to produce the greatest and most stupendous effects, you have a full proof not only of the power of fire, but also of the wisdom with which it is managed, and withheld from bursting forth to the utter ravage and deftruction of all things; and it is very remarkable, that this fame element, fo fierce and deftru&tive, should yet be fo variously tempered, and applied by Divine Providence, as to be the genial and cherishing flame of all natural life.

So bright and lively are the fignatures of a DIVINE MIND operating and difplaying itself in fire and light throughout the world, that, as Ariftotle obferves," all things feem full of divinities, whofe apparitions on all fides ftrike and dazzle our eyes." And indeed the wifeft men of antiquity, how much foever they attributed to second causes, and the force of fire, yet fuppofed it always to be governed by a mind or intellect active and provident, reftraining it's force, and directing it's ope

rations.

The order and courfe of things, together with what we daily experience, fully proves that there is a mind that governs and actuates this mundane fyftem, as the proper real agent and cause, and that the inferior inftrumental caufe is pure ether, fire, or the fubftance of light, which is applied and determined by an infinite mind in the macrocosm or univerfe with unlimited power, and according to

ftated

ftated rules, as it is in the microcosm with limited power and skill by the human mind. There is no proof from reafon, or experiment, of any other agent or efficient caufe than MIND or SPIRIT. When I speak therefore of corporeal agents, or corporeal caufes, you are to understand them as used in a different, fubordinate, and improper sense.

The principles, whereof a thing is compounded, the inftrument used in it's production, and the end for which it was defigned, are all in vulgar use termed causes, though none of them be, strictly fpeaking, agent or efficient. Therefore when I fpeak of the element of fire as acting, it is to be underfood only as a mean or inftrument, which is indeed the cafe of all mechanical caufes whatsoever. They are nevertheless sometimes termed agents, or caufes, although by no means active, in a strict and proper fignification: when therefore force, power, virtue, or action, are mentioned as fubfifting in an extended, corporeal, or mechanical being, these terms are not to be taken in a true, genuine, réal, but only in a grofs and popular fenfe, which fticks in appearances, and does not analyse things to their first principles. In compliance with eftablished language, and the use of the world, we must employ the current phrafes; but for the fake of truth, we fhould diftinguish their meaning.*

What I have here, as well as in my former Lectures, laid before you, concur in proving, (nay all nature gives teftimony thereto,) "that the fluid etherial matter of the heavens acts by impulse on the folid matter of the earth; is inftrumental in every one of it's productions, and neceffary to all the ftated phenomena of nature. The elements may then be divided ino active and paffive; not that they are fuch by any inherent or effential difference,

Siris, No. 154, 155.

but

but that, according to the order established by the DIVINE ARCHITECT, they are obferved to fubúf under fuch relations."*

OF ANIMAL ELECTRICITY.

I fhall here introduce you to the reafons and experiments, which induced Dr. Shebbeare to adopt electricity, as the principle of vital heat and motion, in 1755; and then fhew how far his opinion has been confirmed by fubfequent information.

A mufcle put into motion by the will, may yet be more actuated by a farther extenfion of volition, as from walking to running; by this operation of the mind, there is more of the vital fire determined to the mufcles employed in those actions; muscles are also brought into action, by the fire from the electric machine, and palfied limbs have been rendered plump by the fame machine, and a power of motion and action reftored to thofe whose palfies have not been of a long standing, and which do not take their fource from the fpinal marrow, This offers a convincing proof, that vital fire is the cause of muscular motion, and that this vital fire is of the fame kind with that produced by our electrical machines.

After fo many experiments on the electrical fluid, and after the difcovery of fo many phenomena, which are no ways to be diftinguished from thofe of fire, it will fcarce be any longer difputed, that they are the fame in their own nature. Nor will any one, I prefume, after the fire put in action in electrical experiments, has been perceived by all our fenfes, fuppofe that there can be lefs reality in it, than in earth, air, water, or fire, whofe reality with refpect to mankind depends on the

* Jones's Effay on the First Principles of Philofophy, p. 8,

the evidence of thofe very fenfes. Electricity communicates ideas to every fenfe; it is light to the eye, odour to the nofe, ftroke to the touch, fubacid to the taste.

If you apply heat, either by means of water, or any other method, to the heart of a viper or of an eel taken from the body of those animals, it will again begin to vibrate. Now heat is fire in action, and thus you fee the fame effect is produced, as was effected in the palfied limb.

The reason why the hearts of vipers, and eels, and fuch like animals, are put into motion by a power of the fame nature, though in a lefs degree than that which moves the hearts of larger animals, is, because they are extremely cold by nature, and therefore a lefs degree of fire actuates on their heart than on thofe of larger animals. It is not improbable, that the fame degree of heat, which is neceffary to keep a fowl alive, would deftroy a frog or viper, and burft the cells of the tunica cellularis. After the heart of a viper has difcontinued to beat with the application of any certain degree of heat, it will vibrate again on the application of a fuperior degree.

The heart, which in the open air had ceased to move with a certain degree of heat, will vibrate again in vacuo with the fame degree; for the preffure of the atmosphere being removed, a lefs power is required to diftend the fibres.

Dr. Shebbeare took the heart of an ecl, which had been fome time dead, and placing it on a card, put it on the conductor; the first motion that was communicated to it, was it's fwelling, or the diaftole of the ventricles, which not being immediately followed by the contraction or fyftole, he took the electrical fpark therefrom, on which it contracted; it then dilated again, and upon the application of his finger again contracted; and thus

having repeated it feveral times, the heart continued to perform it's diaftole and fyftole, without being touched; and when it was removed it ceased, but began again upon being placed on the bar.

Lord Bacon has given us a very remarkable inftance of the effect of fire upon the human heart. He fays, " that upon the embowelling of a criminal, he had feen the heart of a man, after it was thrown into the fire, leap up for feveral times together, at first to the height of a foot and a half, and then gradually lower, to the best of his memory, for the space of feven or eight minutes."

Trace vital heat and motion from their fource, and you will find these phenomena still more clearly illuftrated. An egg, though it include all the parts neceffary for the formation of an animal, will never produce a chicken, unlefs it is kept in a certain degree of heat for a certain time; which heat, regularly conducted, is all that is neceffary to the production of an animal fimilar to the pato,

rent.

That there is nothing more neceffary to the producing this animal from an egg, than commOK fire, has been long known and practifed in Egypt, and demonftrated by Mr. Reaumur. There is no other vital principle transfufed from the hen to the embryo, than from a common fire. Thus is fire plainly proved to be the first mover in the animal machine, and is the only active material or natural principle during it's exiftence; and it is a principle abfolutely neceffary for the prefervation of health, and generating wholefome fluids. Shall fire be allowed to have the power of beginning the vital motion in the womb, or egg, and fhall it be refused the power of continuing it after the birth?

Now, for many reafons which will be feen as we proceed, it appears that the fluid of fire paffes by the nerves to the brain and fpinal marrow, and

from