The works of Francis Bacon, lord chancellor of England.

42 NATURAL HISTORY. CENT. III.
256. Both of them have the whole species in intentive and erect, insomuch as you contract your
every small portion of the air, or medium, so as eye when you would see sharply; and erect your
the species do pass through small crannies without ear when you would hear attentively; which in
confusion: as we see ordinarily in levels, as to beasts that have ears movable is most manifest.
the eye; and in crannies or chinks, as to the 2G67. The beams of light, when they are multisound. plied and conglomerate, generate heat, which is a
257. Both of them are of a sudden and easy different action from the action of sight: and the
generation and delation: and likewise perish multiplication and coglomeration of sounds doth
swiftly and suddenly; as if you remove the light, generate an extreme rarefaction of the air; which
or touch the bodies that give the sound. is an action materiate, differing from the action
258. Both of them do receive and carry ex- of sound; if it be true, which is anciently reportquisite and accurate differences; as of colours, ed, that birds with great shouts have fallen
figures, motions, distances, in visibles; and of down.
articulate voices, tones, songs, and quaverings, in
audibles. Dissents of visibles and audibles.
259. Both of them, in their virtue and working, 268. The species of visibles seem to be emisdo not appear to admit any corporal substance into sions of beams from the objects seen, almost like
their mediums, or the orb of their virtue; neither odours, save that they are more incorporeal: but
again to rise or stir any evident local motion in the species of audibles seem to participate more
their mediums as they pass; but only to carry with local motion, like percussions, or imprescertain spiritual species; the perfect knowledge sions made upon the air. So that whereas all
of the cause whereof, being hitherto scarcely at- bodies do seem to work in two manners, either by
tained, we shall search and handle in due place. the communication of their natures or by the im260. Both of them seem not to generate or pressions and signatures of their motions; the
produce any other effect in nature, but such as diffusion of species visible seemeth to participate
appertaineth to their proper objects and senses, more of the former operation, and the species auand are otherwise barren. dible of the latter.
261. But both of them, in their own proper 269. The species of audibles seem to be caraction, do work three manifest effects. The first, ried more manifestly through the air than the spein that the stronger species drowneth the lesser; cies of visibles: for I conceive that a contrary
as the light of the sun, the light of a glow-worm; strong wind will not much hinder the sight of
the report of an ordnance, the voice: The second, visibles, as it will do the hearing of sounds.
in that an object of surcharge or excess destroyeth 270. There is one difference above all other bethe sense; as the light of the sun the eye; a tween visibles and audibles, that is the most reviolent sound near the ear the hearing: The third, markable, as that whereupon many smaller differin that both of them will be reverberate; as in ences do depend: namely, that visibles, except
mirrors, and in echoes. lights, are carried in right lines, and audibles in
262. Neither of them doth destroy or hinder arcuate lines. Hence it cometh to pass, that vithe species of the other, although they encounter sibles do not intermingle and confound one another,
in the same medium, as light or colour hinder not as hath been said before, but sounds do.. Hence
sound, nor "e contra." it cometh, that the solidity of bodies doth not
263. Both of them effect the sense in living much hinder the sight, so that the bodies be clear,
creatures, and yield objects of pleasure and dis- and the pores in a right line, as in glass, crystal,
like: yet nevertheless the objects of them do also, diamonds, water, &c. but a thin scarf or handker
if it be well observed, affect and work upon dead chief, though they be bodies nothing so solid, hin
things; namely, such as have some conformity der the sight: whereas, contrariwise, these porous
with the organs of the two senses, as visibles work bodies do not much hinder the hearing, but solid
upon a looking-glass, which is like the pupil of bodies do almost stop it, or at the least attenuate
the eye: and audibles upon the places of echo, it. Hence also it cometh, that to the reflection
which resemble in some sort the cavern and of visibles small glasses suffice; but to the restructure of the ear. verberation of audibles are required greater spaces,
264. Both of them do diversely work, as they as hath likewise been said before.
have their medium diversely disposed. So a 271. Visibles are seen further off than sounds
trembling medium, as smoke, maketh the object are heard, allowing nevertheless the rate of their
seem to tremble, and a rising or falling medium, bigness, for otherwise a great sound will be heard
as winds, maketh the sounds to rise or fall. further off than a small body seen.
265. To both, the medium, which is the most 272. Visibles require, generally, some distance
propitious and conducible, is air, for glass or between the object and the eye, to be better seen;
water, &c. are not comparable. whereas in audibles, the nearer the approach of
266. In both of them, where the object is fine the sound is to the sense, the better. But in this
mnd accurate, it conduceth muchto have the sense there may be a double error. The one, because to