of judging of them. Do we but ftand for a few seconds on our head, or turn round, and alter in the brain the current of blood, and how is the image of man, erect, and viewing the heavens, reversed! He who could exclaim, "These are THY wondrous works; How wondrous

then THYSELF!" If more or lefs blood, or that not duly fupplied with the vital principle in the air, be tranfmitted to the brain, how would the ideas of this fublime poet, respecting hideousness and holiness, vice and virtue, be confounded! In the delirium of a fever, even in the mind of a LoCKE, how unproportioned to the reality would be the representation of things!

At Paris there was a man whofe head had been broken and trepanned. If the filver plate was removed, and the cortical part of the brain preffed, his fight would become dim; and if the preffure was increased, he would exhibit the abolition of fenfe and motion, or apoplexy, and immediately upon taking away the preffure (which he earneftly begged might be continued but a very short time), all his faculties returned unhurt.

The connection of mind and matter however muft not be confounded. The UNDERSTANDING, indeed, is the refult of mechanism. A nerve is an infinite affemblage of minute threads. Thefe acquire force by exertion,

thus

thus, in learning to repeat by memory, the electic impulfe of each word becomes concatenated, so that by reading the fame thing over and over again, the whole leffon is acquired: thus the multiplication table is readily got by rote, and, when a boy is asked, how much is times 9? he begins 4 times 4 is 16, and fo gets down at laft to 4 times 9 is 27.

To evince the fibrous ftructure of the ORGANS of SENSE, the retina* of an ox was suspended in a glass of warm water, and fome cauftic alkali being added to it, as the adhering mucus was corroded, the hair-like fibres remained floating in the veffel.

Hence it seems, that the ORGANS of SENSE are compofed of minute fibres; and it is probable that the locomotive muscles, as well as the vascular ones, of microfcopic animals have much greater tenuity than thefe fibres of the retina.

Befides the fimilar laws, which will be fhewn in this volume to govern alike the actions of fentient and muscular fibres, there are many other analogies which exist between them.

They are both originally excited by irritations from without, are alike strengthened and fatigued by exertions, *The expanfion of the OPTIC NERVE.

VOL. IV.

b

are

are alike painful if excited into action when inflamed, and are alike subject to spasm, paralysis, and the torpor, of declining years.

The retina, as was before fhewn, is an expanfion of the optic nerve. Its branches are composed of infinite fibres. A part of these being exercised conveys a distinct idea. If the impulse be strong, the object is clear; if weak, the object is diftant, and confused.

It is probable that fight bears no reference to the image of objects; no more than a looking-glass fees, because it reflects the image of different objects: the image on the concavity of the eye is topfy turvy, and double to those who have two eyes; but the idea is the refult of impreffion upright and single.

By this organ we can clearly explain our notion of INTELLECT as dependant upon mechanism. If the mechanism of the eye be defective, we can acquire no ideas which refult from this fenfe. If the optic nerve be palfied, or, on the contrary, if inflamed, that is, supplied with too much blood, or if jaundiced, fight is loft or imperfect; or if we make gyrations round one foot with the eyes fhut, when we afterwards open them, the image of objects will appear in rotatory motion.

Sight or vifion, therefore, depends on mechanism, but ftill it must not be confounded with it. For the MIND or soul has a much higher origin than that of the perishable frame with which it is at prefent connected. It is

neither
agents in this its incarcerated ftate.

nerve nor the electric fluid.

66

These are only its

When the "
When the "filver

cord" is broken, which connects MIND and MATTER together, vitality ceases, the body then, with all its artful and numerous veffels, fibres, and nerves, and other exquifite machinery, undergoes decompofition, and is turned into its original elements; but the IMMORTAL SOUL, having fhaken off this coil, is destined for a new refidence; to flourish in eternal youth; to outlive the wreck of elements, and the crash of worlds.

II. OF GANGLIONS.

Befides progreffive motion, the various movements of the hands, and other parts of animal bodies, which are performed by MUSCLES curiously fashioned for each purpofe and wifely distributed, there are other motions that, on the contrary, have little or no dependance on our inclination. Of this kind are the actions of the heart; the circulation of the blood; the motions of the stomach, and inteftines; the progrefs of the chyle to the subclavian vein ; the movement of the various fecreted liquors, fuch as the gall; the faliva; &c. These, together with the lungs in refpiration, have received the denomination of VITAL OF INVOLUNTARY MOTIONS, because they go on without any confcious exertions of the intellectual principle.

If fuch a variety of nice and complicated movements had been left to the determination of the will, it had occupied every moment of our thought, and had stopped during fleep, when consciousness is totally obliterated. We therefore here clearly difcern the goodness of the ALMIGHTY, which has given man the absolute direc