Physiologia Epicuro-Gassendo-Charltoniana, or, A fabrick of science natural, upon the hypothesis of atoms founded by Epicurus repaired [by] Petrus Gassendus ; augmented [by] Walter Charleton ...

SECT. I.

IT was a hypochondriack conceit of Plato,* 1.1 that all our Cognition is but Recognition, and our acquired Inte••∣lection a meer Reminiscence of those primitive lessons the Soul had for∣gotten since her transmission from the sphere of supreme Intelligences, and Immersion into the Opacity of Flesh. For, Proper Science is pro∣per only to Omniscience; and not to have knowledge by infusion or ac∣quisition, is the attribute only of the Essence of Wisdom; and a priviledge due to none but the Ancient of Dayes, to have his knowledge derived be∣yond Antiquity: but Man, poor ignorant Thing, sent to School in the World, on the design of Sapience, must sweat in the exploration and pursuit of each single Verity; nor can he ever possess any science, in this dark region of life, but what he hath dearly purchased with his own anxious discovery, or holds by inhaeritance from the charitable industry of his Fore-fathers. And, that the naked Mind of m••n, endowed only with a simple Capacity of Science, might by degrees adorn it self with the no∣tions of whatever concerns his well-being either in this state of Mortality, or that future one of Immortality▪ hath the Bounty of his Creator furnish∣ed him with the Sense of HEARING: a sense particularly and eminently ordained for Discipline. For, though we sing Hymns to the Eye, for the Invention: yet must we acknowledge a sacrifice of gratitude due to the Ear, for the Communication and Diffusi••n of Arts and Sciences. Quemadmodum aspectus ad vi••ae dulcedinem, & ••ommoda ••st magis necessarius:

ita Auditus ad excipiendam artem, scientiam▪ & sapientiam est accommo∣datior: ille ad inventionem, hic ad communicationem aptior est; saith that accurate and eloquent Anatomist, Iulius Casserius Placentinus, (in premio ad libr. de sens. organ.). Thus much the antique Aegyptians in∣timated in their Hieroglyphick of Memory, the figure of a mans Ear; and the Philosopher exprest in his Character of the Hearing, Auditus est sen∣sus Disciplinae; as also that Modern Ornament of Germany, Sennertus (in hypomn. Phys.) in this memorable sentence; Aures in homine quasi por∣ta mentis sunt, per quam illi communicantur, quae doctrina & institutione de Deo, & alijs rebus necessarijs traduntur, quaeque nullo alio sensu ad∣disci possunt. Now, to bring you home to the scope of this (not other∣wise or unreasonable, or unnecessary) Elogy of the Hearing; since the Relation betwixt the Sight and Hearing is so great, as to the point of mans acquisition of Knowledge, as that the one can be no more justly called the Discoverer, than the other the Propagator of all Arts and Sciences: it is evident we have made no undecent Knot in the Clue of our Method, by immediately subnecting this Enquiry into the Nature of a Sound, the ad∣aequate and proper object of the Hearing, to our praecedent speculations of the Nature of Vision, Colours, and Light.

Besides, as these two Senses are Cousin-Germans,* 1.2 in their Uses and Ends: so likewise are they of near Alliance, in their Objects; there being no small, nor obscure Analogy, betwixt the nature and proprieties of a Vi∣sible Species, and the nature and proprieties of an Audible Species, or Sound. For

(1) As ••t is the property of Light, transfigured into Colours, to re∣present the different Conditions or Qualities of bodies in their superficial parts, according to the different Modification and Direction of its rayes, either simply or frequently reflexed from them, through the Aer, to the Eye: so is it the propriety of Sounds to represent the different Conditions or Qualities of Bodies, by the mediation of the Aer percussed and broken by their violent superficial impaction, or collision, and configurate into swarms of small consimilar masses, accommodable to the Ear. So that He speaks as Philosophically, who saith; that various sounds are no more but the various Percussions and imprest Motions of the Aer: as He that saith, Colours are no more then the various Immersions of Light into the superficial particles of bodies and respective Emersions or Reflections from them, through the diaphanous medium to the Eye. Nor can we much dislike the conceipt of Athanas Kircher. (Musurgiae Universalis l. 9. part. 4. praelus. 1.) that if it were possible for a man to see those subtle motions of the aer, caused by the strings of an instrument, harmonically playd upon (as we may the Circular Undulations, and Tremblings of water, raised by a stone thrown into it, in a river or standing lake) the whole Tune would appear to him like a well drawn Picture, ingeniously and regu∣larly adumbrate with admirable variety of Colours, each one distinctly representing the particular Condition of that string or sonant Body, that created it.

(2) As Light immediately fails and disappears upon the remove or eclipse of its lucid fountain;* 1.3 as is manifest by the succession of darkness in a room at night, when a candle is either removed out of it or extinguished,

the succession of its rayes being intercepted: so doth a Sound instantly perish upon the Cessation of the undulous motion of the Aer, which con∣duceth not only to the Creation, but Delation of it, as the principal, if not the sole Vehicle. For, the subsistence of Sounds is not by way of dependence upon the solid bodies, by which they were produced; accord∣ing to the 7 Proposit. of Mersennus (Harmon. lib. 1. pag. 3.) Soni non pen∣dent à corpore, à quo primum producti sunt: but upon the Continuation of the motion imprest upon the Aer, so that the Duration of a Sound is equal to the duration of the Agitation of the aer. And therefore Bapt. Porta, Cornelius Agrippa, Wecherus, Alexius, and others of the same tribe, that so highly pretend to Phonocamptical Magick, are worthy more than de∣rision, for their insolent undertaking to Conserve a voice, or articulate sound of many syllables, by including it in a long Canale of Lead, or other im∣pervious matter; so that upon unstopping the extreme of the Tube, after many not only hours, but months, the voice shall issue out as quick and distinct as at the first pronunciation, or insusurration into the cavity thereof. Which (whether more impudent, or ignorant (for both Ex∣perience and the Nature of a Sound evidence the contrary) is disputable) Rhodomantade is demonstrated to be absolutely impossible, by Athanas. Kircher. (Musurgiae Universal. lib. 9. & Magiae Echotectonicae cap. 1.) whe∣ther we remit the unsatisfied.

* 1.4(3) As the Actinobolism, or Deradiation of Light from the Luminary, is Sphaerical, in respect of the circumambient space illuminate by it: so is the Diffusion of a Sound in excentral lines from the sonorous body, through the whole space, or medium within the sphere of its vertue; for, otherwise a General, speaking in the midst of his Army, could not be heard in round. Here is the only difference betwixt the Actinobolism of Light and Sounds; that the one is performe•• in time imperceptible, though not instantaneous: the other in moments distinguishable, which are more or less according to the degrees of distance betwixt the sonant and audient. Again, as the Dera∣diation of Light, considered meerly as Visible, not as Lucidum, is Conical, or Pyramidal, in respect to the Eye of the Spectator; as we have profes∣sedly demonstrated in the 10. Article of the 1. Sect. of our Chapt. concern∣ing the Nature of Light: so likewise doth every sound make a Cone, or Pyramid in the medium, whose Base consisteth in the extreme of the body producing the sound, and cone in the ear of him that hears it; or as some Mathematicians, as Blancanus and Mersennus, whose Base is in the Ear, and Cone in some one point of the sonorous subject. Allowing only this Difference; that the Cones or Pyramids of Visible Species are more Geometrical, i. e. more exactly conform to proportion Geometrical, than those of Audible Species; which in regard as well of the grossness of their Particles, as less velocity of their motion, are easily injured and perturbed by Winds. And this, in truth, is the best ground they have to stand upon, who opinion Sounds to be no more but simple Motions of the Aer.

* 1.5(4) As Visible Species, so do Sounds inform the Sense, of the Magnitude, Figure, and other Qualities of the Bodies, from which they are emitted. For experience assureth, that Greater Bodies emit a Graver Sound, than smaller; that Concaves yeild a stronger and more lasting Sound, than Planes; that Hard things sound more Acutely than Soft;

strings distended yeild a sharper sound, than lax; Empty vessels than full, &c. Hence is it, that Goldsmiths, and Coyners distinguish good mony from bad, pure Gold from that largely allayed with Copper; and Metallists judge of simple and compound Metals, only by their Ring or sound. And we have heard of Vintners, who could exactly distinguish the Kinds and Goodness of Wines, only by the sound of the Vessels that con∣tained them: and therefore used to choose them more by their Ear, than Palate. But, what we here say, that Harder Bodies emit a sound more Acute than softer; we desire may be understood only of the Plurality, not Generality of Bodies. For the examining Mersennus, having experimented the different sounds of Metalls, tells us (in praefat. ad Harmonic.) that He found a Cylindre of Iron to be Unisone to another of steel, equal in diametre and length; and both in acuteness to transcend a Cylindre of Brass of equal dimensions, by a whole Diatessaron: nay more, that a Cylin∣dre of Firr Wood yeilded, upon equal percussion, a sound more acute by a whole Ditone, than a Cylindre of Brass, which yet yeilds a sound more strong, lasting and grateful than any of the rest. Each of which observations is suf∣ficient to cut off the general intaile of that Canon, Sonos eò acutiores, quo duriora fuerint corpora. Legendus est Athanas. Kircher. Art. Magn. Conso∣ni & Dissoni lib. 1. appendice de Phonognomia.

(5) As a Greater Light alwayes obumbrates a Less,* 1.6 so a Great Sound alwayes drowns a Less: for it is manifest, that the sound of a Trumpet conjoyned to the low or submissive voice of a man, makes it wholly unaudible, and the loud clamours of Mariners are scarce heard in a tempest.

(6) As a too great Light offends alwayes, and often destroyes the sight,* 1.7 as is eminently exemplified in the tyranny of Dionysius, the Sicilian: so, too great sounds injure and lacerate the Hearing. For, many men have been strucken deaf for ever, by great Thunder-claps, and as many by the re∣ports of grand Artillery.

(7) As Light, meerly by the Condensation of it rayes,* 1.8 produceth Heat in the aer: so Sounds meerly by their Multiplication. For, it is observed, that in all Battails, and chiefly in Naval fights, where many Cannons are fre∣quently discharged, the aer becomes soultry and hot; not so much from the many sulphureous or igneous particles of the Gunpowder commixt with, as the violent concussions, and almost continued agitation of the Aer. So that even in this particular, that Axiom, that Motion is the Mother of Heat, holds exactly sound.

(8) The Effects of Audible Species, as well as of Visible,* 1.9 are subject to variation, according to the divers Condition of the Medium. For, as Flame, beheld through smoak, seems to tremble: so do sounds, trajected through aer variously waved by Winds, rise and fall betwixt every Gust; as is ob∣servable most easily in the ringing of Bells, whether the wind be favourable, or adverse.* 1.10

(9) And what most conduceth to our comprehension of the Nature of a Sound; For, as Light, so is a Sound capable of Locomotion, Exsilition, Impaction, Resilition, Disgregation, Congregation; all which are the proper

and incommunicable Attributes of Corporiety. Only we must confess them discrepant in this, (1) That Sounds are delated from their Ori∣ginal not only in direct lines, but circular, elliptical, parabolical, and all others; for a sound heard on the other side of a high Wall, comes not to the ear in a direct line through the Wall, as Kircherus contends (in Musurgiae Universal. lib. 1.) with taedious arguments, but in an Arch, as the incomparable St. Alban hath firmly evinced (in Cent. 3. Natural. Hist.): whereas Light constantly progress through the Medium to the Eye, in Direct lines, whether primary, reflex, or refracted. (2) A Sound is diffused through it sphere of acti∣vity in a longer space of time, by much, than Light, as is sensibly demonstrated by this, that the flash of a Cannon arrives much soo∣ner at the Eye, than the report at the Ear: and the immediate Reason hereof is the less velocity of motion in the sound, which con∣sisting of grosser particles than those of Light, must be proportio∣nately slower in its Delation. For, a Sound seems to be nought but the Aer, at least the subtler or more aethereal part of aer, extrite and formed into many small (Moleculae) masses, or innumerable mi∣nute Contextures, exactly consimilar in Figure, and capable of affecting the Organ of Hearing in one and the same manner: which configurated small masses of aer fly off from bodies compulsed or knockt each against other, with some violence; and progress by Diffusion in round. For, because upon pressure they mutually recede, each particle going off in that point where it finds the freest egress: therefore must some tend up∣ward, others downward, some to the right, others to the left, some ob∣liquely, others transversly, &c. but all more slowly than the particles of Light, whose Tenuity being far greater, causeth them not to be subject to retardment by the like tumultuous Convolution. But, as the greater Cor∣poriety of Sounds makes them slower in their Diffusion; so doth it make them more impetuous and forcible in their Impaction, than the Species of Light: it being obvious to observation, that Violent Sounds, such as great Thunders, Volleys of Cannon shot, the breaking of Granades, &c. usually shake the largest Buildings, and shiver Glass windows at a mile distance and more. And yet are Sounds far easilier impeded, perturbed, and flatted, than the rayes of Light; every man knowing that no sound can penetrate Glass, but in one case, or exigent of Nature, of which we shall particularly speak, in the last Section of this Chapter: and since Sounds are repercussed more slowly; they 〈◊〉〈◊〉 Disgregated more hardly, and Congregated more faintly, than the rayes of Light. Lastly, the Proportion of Retar∣dation in the diffusion of Sounds to the utmost of their sphere of acti∣vity, is such even from Winds; that as Mersennus hath computed, the diameter of the sphere of a sound, heard against the wind, is by almost a third part less than the diameter of the sphere of the same sound, assisted by a favourable or secund Wind: but the Diameter of a Lucid Sphere is alwayes equ••••, which way soever and how violently soever the wind blows. (3) Bodies of narrow Dimensions make a sensible reflection of Light; as is manifest from a Burning-glass of an inch diameter: but a Body of far greater dimensions is required to the sensible Reflection of a Sound, i. e. to the production of an Eccho; though it is not to be doubted, but •• ••ound may be reflected from every Hard bodie on which it is impinged. This considered, we cannot but smile at the Credulity of many grea•• Aristoteleans, who are persuaded that an Echo is made

by the meer Repercussion of the Sound from the particles of the Aer. For, notwithstanding we deny not, but the particles of the aer, within the sphere of the Sounds diffusion, encountring and arietating those particles of the sound, may in some small measure repercuss them: yet we think it unsafe, therefore to admit this aereal Repercussion to arise to Sensibility, or to be observable by the Creation of an Echo. And therefore we conceive, that whatever sensible Reflection or Multiplication of a Sound, seems to proceed from the Aer, is not caused really by the Aer, but some Dense and Hard Bodies, such as Rocks, Aedifices, Arches, &c. whose Concavities reflect the particles of a Sound for the same reason, that Concaves Multiply Light.

Notes

• * 1.1

  Art. 1. An Elogy of the sense of Hearing: and the Relation of this and the praecedent Chapter.
• * 1.2

  Art. 2. The great Affi∣nity betwixt Vi••ible ••nd Au∣dible species: in their repre∣sentation of the superficial Conditions of Objects.
• * 1.3

  Art. 3. In the Causes and manner of their Destru∣ction.
• * 1.4

  Art. 4. In their Acti∣n••bolism, or Diffusion, both Sphaerical and Pyramidal.
• * 1.5

  Art. 5. In their certi∣fying the sense of the Magni∣tude, Figure, and other•• Qualities of their Origi∣nals.
• * 1.6

  Art. 6. In the obscu∣ration▪ of Less by Greater.
• * 1.7

  Art. 7. In their of∣f••nce of the or∣gans, when excessive.
• * 1.8

  Art. 8. In th••ir pro∣duction of Heat by Multi∣plication.
• * 1.9

  Art. 9. In their Varia∣bility, accord∣ing to the va∣rious dispositi∣on of the Me∣dium.
• * 1.10

  Art. 10. In their chief Attributes, of L••comotion, Ex∣siliti••••, ••mpacti∣on, Resilition, D••••gregation, Cong••egation▪