by a due dose, might in good measure check that wasting inflammation which steals on with age.

An experiment is inverted when the contrary of what the experiment shows is proved; for example, heat is increased by burning glasses; but may cold be so too? So heat in diffusing itself rather mounts upward, but cold in diffusing itself rather moves downward. Thus, if an iron rod be heated at one end, then erected upon its heated end, and the hand be applied to the upper part of the rod, the hand will presently be burned; but if the heated end be placed upward and the hand applied below, it will be burned much slower. But if the whole rod were heated, and one end of it wet with snow or a sponge dipped in cold water, would the cold be sooner propagated downward than upward if the sponge were applied below? Again, the rays of the sun are reflected from a white body, but absorbed by a black one. Are shadows also scattered by black and collected by white bodies? We see in a dark place, where light comes in only at a small hole, the images of external objects are received upon white paper, but not upon black.

An experiment is compelled where it is urged or produced to the annihilation or destruction of the power, the prey being only caught in the other chases, but killed in this. Thus the loadstone attracts iron-urge, therefore, the iron, or urge the loadstone, till they attract no longer; for example, if the loadstone were burned, or steeped in aquafortis, would it entirely, or only in part, lose its virtue? So if iron were reduced to a crocus, or made into prepared steel, as they call it, or dissolved in aqua-fortis, would the loadstone still attract it? The magnet draws iron through all known mediums-gold, silver, glass, etc. Urge the medium, therefore, and, if possible, find out one that intercepts the virtue. Thus make trial of quicksilver, oil, gums, ignited gold, and such things as have not yet been tried. Again, microscopes have been lately introduced which strangely magnify minute objects; urge the use of them, either by applying them to objects so small that their power

is lost, or so large till it is confounded. Thus, for example, can microscopes clearly discover those things in urine which are not otherwise perceptible? Can they discover any specks or clouds in gems that are perfectly clear and bright to appearance? Can they magnify the motes of the sun, which Democritus mistook for atoms and the principles of things?16 Will they show a mixed powder of vermilion and ceruse in distinct grains of red and white? Will they magnify larger objects—as the face, the eye, etc.—as much as they do a gnat or a mite, or represent a piece of fine linen open as a net? But we need not insist longer on compulsory experiments, as they do not justly come within the limits of literate experience, but are rather referred to axioms, causes, and the New Organum.

The application of an experiment is no more than an ingenious translation of it to some other experiment of use; for example, all bodies have their own dimensions and gravities. Gold has more gravity and less bulk than silver, and water than wine-hence a useful experiment is derived for discovering what proportion of silver is mixed with gold, or of water with wine, from a knowledge of their measure and weight, which was the grand discovery of Archimedes." Again, as flesh putrefies sooner in some cellars than in others, it were useful to transfer this experiment to the examination of airs, as to their being more or less wholesome to live in, by finding those wherein flesh remains longest unputrefied; and the same experiment is applicable to discover the more wholesome or pestilential seasons of the year. But examples of this kind are endless, and require that men should have their eyes continually turned one while to the nature of things and another while to human uses.

16 Epistles of Hippocrates, or Pliny's Nat. History.

17 The means that Bacon proposes, and to which the chemists still adhere, is the reverse of that of Archimedes. The ancient compared, in his experiment, three bodies of the same weight, but of different volume, while the text advises three bodies of the same volume, but of different weight. This reversion, however, does not affect the result.-Ed.

The conjunction of an experiment is a connection and chain of applications, when those things which were not useful single, are made useful by connection; for example, to have roses or fruits come late, the way is to pluck off the early buds, or to lay bare the roots and expose them to the open air, toward the middle of spring; but it is much better to do both together. So ice and nitre separate have a great power of cooling, but a much greater when mixed together. But there may be a fallacy in this obvious affair, as in all cases where axioms are wanting, if the conjunction be made in things that operate by different and, as it were, contrary ways."

As for chance experiments, these are plainly an irrational and wild procedure, when the mind suggests the trial of a thing, not because any reason or experiment persuades it, but only because nothing of the kind has been tried before; yet even here, perhaps, some considerable mystery lies concealed, provided no stone in nature were left unturned; for the capital things of nature generally lie out of the beaten paths, so that even the absurdness of a thing sometimes proves useful. But if reason also be here joined, so as to show that the like experiment never was attempted, and yet that there is great cause why it should be; then this becomes an excellent instrument, and really enters the bosom of nature. For example, in the operation of fire upon natural bodies it has hitherto always happened that either something flies off, as flame and smoke in our common fires, or at least that the parts are locally separated to some distance, as in distillation, where the vapor rises and the fæces are left behind; but no man has hitherto tried close distillation. Yet it seems probable, that if the force of heat may have its action confined in the cavities of a body, without any possibility of loss or escape, this Proteus of matter will be manacled, as it were, and forced to undergo

18 Such are the compounds of very active substances, which chemists designate neuter: for example, the greater part of salts, as nitre, sea-salt, the salt of Glauber, and generally all those substances composed of an acid united to an alkaline or earthy base.-Ed.

numerous transformations, provided only the heat be so moderated and changed as not to break the containing vessel. For this is a kind of natural matrix, where heat has its effect without separating or throwing off the parts of a body. In a true matrix, indeed, there is nourishment supplied; but in point of transmutation the case is the same. And here let none despair or be confounded, if the experiments they attempt should not answer their expectation; for though success be indeed more pleasing, yet failure, frequently, is no less informing; and it must ever be remembered, that experiments of light are more to be desired than experiments of profit. And so much for learned experience, as we call it, which thus appears to be rather a sagacity, or a scenting of nature, as in hunting, than a direct science."

As regards the Novum Organum, we shall state here nothing either summarily or in detail, it being our intention, with the Divine assistance, to devote an entire treatise to that subject, which is more important than all the rest.

CHAPTER III

Division of the Invention of Arguments into Promptuary, or Places of Preparation, and Topical, or Places of Suggestion. The Division of Topics into General and Particular. An Example of Particular Topics afforded by an Inquiry into the Nature of the Qualities of Light and Heavy

Τ

HE invention of arguments is not properly an invention; for to invent, is to discover things unknown before, and not to recollect or admit such as are known already. The office and use of this kind of inven

19 This section appears to have been little understood even by some eminent men, who censure the scheme of the author, and think that experiments must need be casual, and the human understanding unable to direct and conduct them to useful purposes unless by accident. The misfortune seems to lie here, that few converse so familiarly with nature as to judge what may be done in this way; or how the numerous discoveries of Lord Bacon, Mr. Boyle, Dr. Hook, Sir Isaac Newton, etc., were made. An attentive perusal of the Novum Organum, where this subject is largely prosecuted, will unravel the mystery.—Shaw.

tion seems to be no more than dexterously to draw out from the stock of knowledge laid up in the mind such things as make to the present purpose; for one who knows little or nothing of a subject proposed, has no use of topics or places of invention, while he who is provided of suitable matter, will find and produce arguments, without the help of art and such places of invention, though not so readily and commodiously; whence this kind of invention is rather a bare calling to memory, or a suggestion with application, than a real invention. But since the term is already received, it may still be called invention, as the hunting in a park may be called hunting no less than that in the open field. But not to insist upon the word, the scope and the end of the thing itself, is a quick and ready use of our thoughts, rather than any enlargement or increase of them.

There are two methods of procuring a stock of matter for discourse; viz., 1, either by marking out, and indicating the parts wherein a thing is to be searched after, which is what we call the topical way; or 2, by laying up arguments for use, that were composed beforehand, relating to such things as frequently happen and come in dispute; and this we call the promptuary way: but the latter can scarce be called a part of science, as consisting rather in diligence than any artificial learning. Aristotle on this head ingeniously derides the Sophists of his time, saying, they acted like a professed shoemaker, who did not teach the art of shoemaking, but set out a large stock of shoes, of different shapes and sizes.' But it might be replied, that the shoemaker who should have no shoes in his shop, and only make them as they were bespoke, would find few customers. Our Saviour speaks far otherwise of divine knowledge, saying, "Therefore every scribe which is instructed into the kingdom of heaven, is like unto a man that is an householder, which brings forth out of his treasure things new and old.”2

We find also that the ancient rhetoricians gave it in

1 De Reprehen. Soph. ii. 9.

2 St. Matt. xiii. 52.