The works of Francis Bacon, lord chancellor of England.

542 OF SOUND AND HEARING.
ner inanimates proportionate, and having (as cured of cataracts of the eyes, when the little silseemeth) a conformity with the organs of the ver needle moved over the very pupil of his eye,
senses; as colours, a mirror, that is crystalline and did touch it, he, without any medium, (that
like the eye; sounds, the places of reverberation, silver needle being far narrower than the pupil
which seem, likewise, to resemble the bone and itself of the eye,) saw perfectly the needle. The
cavern of the ear. second, that the cave of the ear is distinctly interBoth work diversely, accordingly as they have posed before the organ of hearing, so as, being
their mediums well or ill disposed. without, the sound is altogether unable to touch
To both the medium the most conducible and the bone and membrane of hearing.
propitious is the air. In both the stretching of The species of sight are more swiftly conveyed
the sense, and, as it were, its erection to perceiv- than sounds, as appeareth in the flash and report
ing, availeth somewhat in more nice objects. of guns; also in lightning and thunder, where
the thunder is heard after a while.
I conceive also that the species of sound do
The species of visibles appear to be as if emis- hang longer in the air than visibles. For, although
sions of beams from the visible body, almost like neither do these perish on the instant, as we see
odours. But the species of audibles appear more in a ring spinning, and lute-strings fillipped, and
to partake of a local motion, like the percussions in twilight and the like; yet I deem that sounds,
vwhich are made in the air: that whereas bodies for that they are carried by the wind, stay
for the most part work in two manners, by comrn- longer.
munication of their nature, or by an impression or The beams of light being gathered, induce heat
signature of their motion, that diffusion in visibles also, which is an action diverse from the visible
appeareth more to partake of the former manner; quality. In like manner, if it be true that shouts
in audibles, of the latter. have cast down birds flying over, that is also an
The dilatation of sounds appears to be more evi- action exceedingly diverse from the audible
dently carried by the air than of visibles. For I quality.
judge that a vehement wind shall not so much There seemeth not in visibles to be found an
hinder any visible afar off, as a sound; I under- object as odious, and noisome to the sense, as in
stand the wind blowing contrary. audibles; but they affect it more evenly; for
It is a notable difference, whence also many things foul to sight rather offend by moving of the
less differences flow, that visibles (original light fancy concerning foul things than of themselves;
excepted) are not carried but by right lines, but in audibles the grating of a saw that is sharpwhilst sounds are carried by arcuate lines. ened, and other like sounds, cause a horror; and
Hence it happens, that visibles confound not a discordant note in music is straightways reone another, that are represented together: sounds fused and loathed.
contrarily. Hence it happens, that the solidity It is not assured, that there is refraction in
of the substance seems not greatly to hinder sight, sounds, as in beams. But, doubtless, sounds do
provided only the positions of the parts of the rebound: but that is to be ascribed to reflection.
body be after a simple order and with straight For, I do not think, if sounds pass through
passages, as in glass, water, crystal, diamond; diverse mediums, as air, cloth, wood, that there
but a little silk or linen cloth breaks the sight, be one place of the sound, where it is carried, anthough they be bodies very thin and porous; but other where it is heard, which is the property of
cloths of this kind little or nothing hinder hearing, refraction; but refraction seems to depend upon
which those solids do exceedingly. Hence it action, in right lines, which pertains not to sound.
happens, that unto the reverberation of visibles a But contraction of sound, and its dilatation, acsmall mirror suffices, or like transpicuous body, cording to the disposition of the medium, happens,
let it be only placed in a right line, where the undoubtedly, as in the speaking of puppets, and
visibles pass; but unto making of the reverbera- under water: the sound is contracted within that
tion of echo, it needeth also to confine the sound cell, which abroad is dispersed; as by mirrors
from the side, because it is carried to all sides. visibles are dilated and contracted.
The visible object is further carried, in proportion, A tremulous medium (as smoke in visibles)
than sound. makes the visible objects also to tremble; but in
Visibles, too nearly approached to the eye, are sounds nothing such is yet found, unless, pernot so well seen as at some little distance, so as the chance, the rise and fall by winds. For the
beams may meet in a more acute angle; but in trembling in the nightingale-pipe is trembling of
hearing, the nearer the better. But herein there the percussion, not of the medium.
may be twofold error. The first, because to see- Going from great light into the dark, or out of
ing there is required light; but if the object be the dark into the light, the sight is some little
brought very near to the eye, this is shut out. confused; but whether the like be after very loud
For I have heard of one trustworthy, which was noises, or a great silence, would be inquired.