spirits in a dangerous disease, it need not be doubted that something of a similar nature, made familiar to the system by well-proportioned doses, may likewise in some measure check and retard that continually advancing and creeping fever which is the effect of age. And so much for the Translation of Experiment. Inversion of Experiment takes place when trial is made of the contrary of that which has been by the experiment proved. For instance, heat is increased by burning-glasses; is cold also? Again, heat spreads round, but with a tendency upwards; does cold spread round with a tendency downwards? For example: take an iron rod and heat it at one end; then raise it, with the heated part downwards and the hand above; it will burn the hand at once: hold it with the heated part upwards and the hand below, it will be much longer in doing so. But how if the whole bar be heated, and one end touched with snow or with a sponge dipped in cold water? will the cold travel downwards, if the snow or sponge be applied to the top, faster than upwards if applied to the bottom? Again, the rays of the sun are reflected from white but collected on black; are shadows likewise lost on black and collected on white? As we see in a dark room, where the light is only let in by a little chink, that the images of things outside are received on a white paper, but not on a black. Again, the megrims are relieved by opening a vein in the forehead; is a pain in the forehead relieved by scarifying the skull? And so much for the Inversion of Experiment. Compulsion of Experiment is when an experiment is urged and extended to the annihilation or deprivation of the power; for in the other hunts the prey is only caught, but in this it is killed. Here is an example of compulsion. The magnet attracts iron; urge the iron or the magnet till it can attract no longer; for instance, if the loadstone be burnt, or steeped in aqua fortis, will it lose its power entirely or for a time? On the other hand, if iron or steel be reduced to oxide of iron, or to what is termed prepared steel, or if it be dissolved in aqua fortis, will it still be attracted by the loadstone? Again, the magnet attracts iron through all mediums we know of; as gold, silver, and glass; find some medium, if it be possible, which will intercept the power; try quicksilver; try oil, gums, ignited coal, and other things, hitherto untried. Again, glasses have lately been invented which magnify minute visible objects in a wonderful manner; urge the use of them to objects either so small as to be beyond their power or so large as to confound it. Thus, can they clearly detect in urine things otherwise imperceptible? Can they discover specks or flaws in jewels which appear every way clear and bright? Can they make the motes in the sunbeams (which were objected most unjustly to Democritus as if they were his atoms and principles of things) appear like great bodies? or a thick powder of vermilion and white lead appear so distinct that the red and the white grains shall be seen separately? Again, can they magnify larger figures (say a face, or an eye) as much as they can a flea or a mite? Can they make a piece of cambric, or any of these finer and more open linen textures, appear full of holes, like a net? But on the compulsions of experiments I dwell the less, because they commonly fall outside the limits of learned experience, and are rather referred to causes, and axioms, and the New Organon. For wherever a case is established of negation, privation, or exclusion, there is some light given towards the invention of Forms. And so much for the Compulsion of Experiment. Application of Experiment is nothing but the ingenious translation of it to some other useful experiment. For instance; all bodies have their own dimensions and gravities; gold has more weight, but less dimension than silver; water than wine. From this is derived a useful experiment; for by taking the bulk and the weight you may know how much silver has been mixed with gold, or how much water with wine; which was the Eupka of Archimedes. Again, flesh putrefies sooner in some cellars than in others; it would therefore be useful to apply this experiment to the discovery of airs more or less healthy to live in; those namely, in which flesh is longest in putrefying. The same method may be applied to discover healthy and unhealthy seasons of the year. But there are innumerable instances of this kind. Let men only watch, and keep their eyes continually turned to the nature of things on one side, and to the uses of man on the other. And so much for the Application of Experiment. Coupling of Experiment is the link or chain of applications; when things which would be ineffectual singly are effectual in conjunction. For example; you wish to have roses or fruit come late. It will be effected, if you pluck off the earlier buds; it will be effected likewise if you uncover the roots and expose them to the air until the middle of spring; but much more if the two be coupled together. Again, ice and nitre have both of them great power of refrigeration; much more when mixed. This is indeed clear of itself. And yet there may often be a deception in it (as in all things else where axioms are wanting), if the things sc coupled be such as operate in different and contrary ways. And so much for Coupling of Experiment. There remain the Chances of Experiment. This form of experimenting is merely irrational and as it were mad, when you have a mind to try something, not because reason or some other experiment leads you to it, but simply because such a thing has never been attempted before. Yet I know not but in this very process (of which we are now treating) some great thing may be involved; the leaving (I say) of no stone in nature unturned. For the magnalia of nature generally lie out of the common roads and beaten paths, so that the very absurdity of the thing may sometimes prove of service. But if reason go along with it; that is, if it be evident that an experiment of this nature has never been tried, and yet there is great reason why it should be tried ; then it is one of the best ways, and plainly shakes out the folds of nature. For instance, when fire works upon a natural body, one of two things has hitherto always happened; —either that something flies out (as flame and smoke in common combustion), or at least that there is a local separation of the parts, and to some distance; as in distillation, where the dregs settle at the bottom, and the vapours, after they have had their play, are gathered into receptacles. But of what I may call close distillation no man has yet made trial. Yet it seems probable that the force of heat, if it can perform its exploits of alteration within the enclosure of the body, where there is neither loss of the body nor yet means of escape, will succeed at last in handcuffing this Proteus of matter, and driving it to many transformations; only the heat must be so regulated and varied, that there be no fracture of the vessels. For this operation is like that of the womb, where the heat works, and yet no part of the body is either emitted or separated. In the womb indeed alimentation is conjoined; but as far as conversion is concerned it seems to be the same thing. Such then are the Chances of Experi ment. Meanwhile I give this advice as to experiments of this nature; that no one should be disheartened or confounded if the experiments which he tries do not answer his expectation. For though a successful experiment be more agreeable, yet an unsuccessful one is oftentimes no less instructive. And it must ever be kept in mind (as I am continually urging) that experiments of Light are even more to be sought after than experiments of Fruit. And so much for Learned Experience, which (as I have already said) is rather a sagacity and a kind of hunting by scent, than a science. Of the New Organon I say nothing, nor shall I give any taste of it here; as I purpose by the divine favour to compose a complete work on that subject, being the most important thing of all. CHAP. III. Division of the art of discovery of Arguments into |
