ESSAY IV.

THE PRINCIPLE OF HOMEOPATHY.

"The discovery of natural truth has been remarkably slow. When the discovery is a single fact many years commonly elapse before the next fact in connection with it is brought to light. When it is of a more general kind, and partakes of the nature of a law, it more commonly suggests other truths and valuable circumstances in connection with it, by which means a more rapid progress is, for a time, made."-SIR JOHN HERSCHEL.

ESSAY IV.

THE PRINCIPLE OF HOMEOPATHY.

66

Experience shows many means to be conducive and necessary to accomplish ends, which means, before experience, we should have thought, would have had even a contrary tendency."-BUTLER, Analogy.

"TRIAL," says Sir William Blackstone, "is the examination of the matter of fact in issue; of which there are many different species, according to the difference of the subject or thing to be tried. This being the one invariable principle pursued, that as well the best method of trial, as the best evidence upon that trial, which the nature of the case affords, and no other shall be admitted."

"Evidence," says the same authority, "signifies that which demonstrates, makes clear, or ascertains the truth of the very fact or point in issue, either on the one side or on the other; and no evidence ought to be admitted to any other point."

The laws of nature are general facts ascertained to be so by inference or induction from a great multitude of particular facts. They are discovered, and their truth proved and maintained, by examining them as matters of fact. They are tried by the best method, and on the best evidence which the nature of the case admits.

It is the distinguished prerogative of a few individuals to discover them, but when once announced they are open to the senses and understanding of all men; they are put to the test of daily experiment and observation, and were they not true, the facts which contradict them would not fail to be speedily discovered.

Every department of nature which has hitherto been successfully studied, so as to constitute it a science, has been founded upon one of these general facts or laws of nature. This is the pole star around which all the minor facts harmoniously turn. For example

The law of specific gravity, or the relative weight of bodies, was discovered by Archimedes, on the occasion of plunging himself into a bath, and, as is familiarly known, so great was his delight that he ran about in an ecstacy, crying out "I have found it-I have found it!" It consists of two facts: 1st.When a solid body is plunged into a liquid, it displaces an amount of liquid equal in bulk to its own bulk. 2dly.The solid body so plunged into a liquid, loses in its weight an amount exactly equal to the weight of the liquid which it has displaced.

The law which is the basis of Mechanics was discovered by Galileo;-The less force equals the greater by moving through more space in the same time.

The law of gravitation, upon which Astronomy is founded, was discovered by Newton;-All bodies attract each other directly as the mass, and inversely as the square of the distance. This is commonly regarded as a mathematical demonstration, but it rests, in reality, upon careful experiments and accurate observation,-like the others, it is a fact proved, when put upon its appropriate mode of trial, by satisfactory evidence.

The law which is the foundation of the science of Hydrostatics, and which has lately been so beautifully applied to a very useful practical purpose in the Bramah press, was discovered by the successive experiments of the three great men just mentioned, Archimedes, Galileo, and Newton. It may be thus expressed;—in a mass of liquid each particle presses equally in all directions.

The laws of Kepler, as they are called from their discoverer, which are three important general facts in Astronomy.-1st

The orbits of the planets are ellipses, with the sun in one of the foci. 2d-The planets move over equal areas in equal times. 3d-The squares of the times of revolution of any two planets are to each other, in the same proportion as the cubes of their mean distances from the sun. "Of all the laws," says Sir John Herschel, "to which induction from pure observation has ever conducted man, this third law of Kepler may justly be regarded as the most remarkable, and the most pregnant with important consequences."

The fact in Physiology that all the higher animals are furnished with a heart and blood-vessels, through which a double circulation of the blood is unceasingly carried on, first through the lungs, and afterwards through the rest of the body; this was the discovery of our illustrious Harvey, who for his pains was set down as crazy, and lost nearly all his practice.

The law for the knowledge of which, we are indebted to the indefatigable labours of Richter and Dalton, and which has given rise to the modern science of Chemistry; Elementary or simple bodies combine with each other, to form compound bodies, in definite or fixed proportions.

The law of storms, ascertained by Col. Reid, which is one of the most recent of these valuable discoveries ;-They move in a circle.

They

All these, and other similar truths, are general facts, which have been put upon their trial, and have stood the test. have been supported by sufficient evidence suited to the nature of each case. Before they were known the departments to which they severally belong were characterised by blunders and guesswork, into which they have introduced method and certainty.

The practical value of this kind of knowledge, may in part be learned by comparing the present condition of the arts with that previous to the discovery of these laws. Had the Romans known the law which regulates the flow of liquids, they would have been spared the vast labour of erecting those magnificent aqueducts for the supply of their cities with water, whose ruins so greatly excite our surprise and admiration at the present day. Our navigation hangs upon the faithfulness of the magnetised bar in turning towards the north;