The works of Francis Bacon, lord chancellor of England.

BooK II. NOVUtI ORGANUM. 415
which latter term we do not mean the simple motions, bodies appear to aim at the mere pregeneration of integral bodies, such as plants or servation of their nature, whilst in this they atanimals, but of homogeneous bodies. By this tempt its propagation.
motion homogeneous bodies convert those which Let the twelfth motion be that of excitement,
are allied to them, or, at least, well disposed and which appears to be a species of the last, and is
prepared, into their own substance and nature. sometimes mentioned by us under that name. It
Thus flame multiplies itself over vapours and is, like that, a diffusive, communicative, transioily substances, and generates fresh flame; the tive, and multiplying motion; and they agree reair over water and watery substances multiplies markably in their effect, although they differ in
itself and generates fresh air; the vegetable and their mode of action, and in their subject-matter.
animal spirit, over the thin particles of a watery The former proceeds imperiously, and with auor oleaginous spirit contained in its food, multi- thority; it orders and compels the assimilated to
plies itself and generates fresh spirit; the solid be converted and changed into the assimilating
parts of plants and animals, as the leaf, flower, body. The latter proceeds by art, insinuation,
the flesh, bone, and the like, each of them assi- and stealth, inviting and disposing the excited
milate some part of the juices contained in their towards the nature of the exciting body. The
food, and generate a successive and daily sub- former both multiplies and transforms bodies and
stance. For let none rave with Paracelsus, who substances; thus a greater quantity of flame, air,
(blinded by his distillations) would have it, that spirit, and flesh is formed; but in the latter, the
nutrition takes place by mere separation, and powers only are multiplied and changed, and
that the eye, nose, brain, and liver, lie concealed heat, the magnetic power, and putrefaction, in
in bread and meat, the root, leaf, and flower, in the above instances, are increased. Heat does
the juice of the earth; asserting that just as the not diffuse itself, when heating other bodies, by
artist brings out a leaf, flower, eye, nose, hand, any communication of the original heat, but only
foot, and the like, -from a rude mass of stone or by exciting the parts of the heated body to that
wood, by the separation and rejection of what is motion which is the form of heat, and of which
superfluous; so the great artist within us brings we spoke in the first vintage of the nature of
out our several limbs and parts by separation heat. Heat, therefore, is excited much less
and rejection. But to leave such trifling, it is rapidly and readily in stone or metal, than in air,
most certain that all the parts of vegetables and on account of the' inaptitude and sluggishness
animals, as well the homogeneous as organic, of those bodies in acquiring that motion, so that
first of all attract those juices contained in their it is probable that there may be some substances,
food, which are nearly common, or at least not towards the centre of the earth, quite incapable
very different, and then assimilate and convert of being heated, on account of their density,
them into their own nature. Nor does this as- which may deprive them of the spirit by which
simnilation, or simple generation, take place in the motion of excitement is usually commenced.
animated bodies only, but the inanimate also Thus, also, the magnet creates in the iron a new
participate in the same property, (as we have ob- disposition of its parts, and a conformable motion,
served of flame and air,) and that languid spirit, without losing any of its virtue. So the leaven
which is contained in every tangible animated sub- of bread, yeast, rennet, and some poisons, excite
stance, is perpetually working upon the coarser and invite successive and continued motion in
parts, and converting them into spirit, which af- dough, beer, cheese, or the human body; not so
terwards is exhaled, whence ensues a diminution much from the power of the exciting, as the preof weight, and a desiccation of which we have disposition and yielding of the excited body.
spoken elsewhere.? Nor should we, in speak- Let the thirteenth motion be that of impress'ion,
ing of assimilation, neglect to mention the accre- which is also a species of motion of assimilation,
tion which is usually distinguished from aliment, and the most subtile of diffusive motions. We
and which is observed when mud grows into a have thought it right, however, to consider it as
mass between stones, and is converted into a a distinct species, on account of its remarkable
stony substance, and the scaly substance round difference from the two last. For the simple mothe teeth is converted into one no less hard than tion of assimilation transforms the bodies themthe teeth themselves; for we are of opinion that selves, so that if you remove the first agent, yomu
there exists in all bodies a desire of assimilation, diminish not the effect of those which succeed;
as well as of uniting with homogeneous masses. thus, neither the first lighting of flame, nor the
Each of these powers, however, is confined, first conversion into air, are of any importance to
although in different manners, and should be the flame or air next generated. So, also, the
diligently investigated, because they are con- motion of excitement still continues for a consinected with the revival of old age. Lastly, it is derable time after the removal of the first agent.
worthy of observation, that in the nine preceding as in a heated body on the removal of the original
heat, in the excited iron on the removal of the
* See the citing instances, Aphorism 40. magnet, and in the dough on the removal of the