Page:Cyclopaedia, Chambers - Volume 2.djvu/969

 VIS

Mence, they define Virtue to be a firm Puipofe or Refo- lution of doing whatever right Reafon demands to be done. For tho a Cuttom of doing well be requir'd to make a Per- fon efteem'd good among Men 5 yet it does not follow, that that Cuttom or Habit is the formal Caufe of that Denomi- nation, or the Goodnefs it felf.

Moralifts ufually dittinguifh four 'Principal, or, as they are vulgarly call'd, Cardinal Virtues, viz. Prudence, Jttjlice-, Fortitude, and 'Temperance ; The Reafon of which Divi- sion is founded in this, That for a Man to live virtuoufly and honeftly, 'tis neceffary he know what is fit to be done; which is the Bufinefs of Prudence.

That he have a conttant and firm Will to do what he judges beft ; which will perfect the Man, either as it re- trains too violent Perturbations, the Office of -Temperance. Or, as it fpurs and urges on thofe that are to flow and languid, which is the Bufinefs of Fortitude.

Or, laftly, comparatively, and with regard to human So- ciety $ which is the Object of Juflice.

To thefe four all the other Virtues arc refer'd, cither as Parts, or as Concomitants.

VIRTUES, in the Hierarchy, the third Rank, or Choir of Angels $ being that in order between "Dominations and 'Powers. See Hierarchy.

- To.thefe is attributed the Power of working Miracles, and of flrengthning and reinforcing the inferior Angels in the Ex- ercife' of their Functions. See Angel.

VIRTUOSO, an Italian Term, lately introduced into EngliJJj 5 fignifying a Man of Curiofity and Learning j or one who loves and promotes the Arts and Sciences.

In Italy, Virtuofi are properly fuch as apply themfelves to the polite Arts of Painting, Sculpture, Turning, Mathema-

ticks, $$c. A Perfon who makes Profeffion thereof, is

call'd Virtuofi, qttefia e un Virtuofo.

Among us, the Term feems affected to thofc who apply themfelves to fome curious and quaint, rather than imme- diately ufeful Art or Study : As Antiquaries, Collectors of Rarities of any kind, Microfcopical Obfervers, f£c.

VIRULENT, a Term apply'd to any thing that yields a Virus ; that is, a corrofive or contagious Pus. See Pus.

The Gonorrhoea Virulenta, is what we popularly call a Clap. See Gonorrhoea.

VIS, a Latin Word, fignifying Force, or Waver 5 adopt- ed by phyfical Writers, to exprefs divers Kinds of Natural Powers : as the

Vis Inertia or 'Power of Inactivity, which is defin'd by Sir 7. Newton to be a Power implanted in ail Matter, whereby it refills any Change endeavour'd to be made in its State, i. e. whereby it becomes difficult to alter its State, either of Reft, or Motion. See Inertia.

This Power, then, coincides with the Vis re/iftendi, Power of refitting, whereby every Body endeavour?, as much as it can, to perfevere in its own State whether of Rett, or uni- form- rectilinear Motion : Which Power is {till proportional to the Body, and only differs from the Vis Inertia of the Mafs in the manner ot conceiving it.

Bodies only exert this Power in Changes brought on their State by fome Vis Impreffa, Force imprefs'd on 'em. And the Exercifc of this -Power, is, in different refpe£ts, both Refiflance, and Impetus ; Refinance, as the Body oppofes a Force imprefs'd on it to change its State ; and Impetus, as the fame Body endeavours to change the State of the refit- ting Obftacle.- "Phil. Nat. Trine. Math. Lib. I. See Re- action.

The Vis Inertia, the fame great Author elfewhere ob- ferves, is a paffive Principle, by which Bodies perfitt in their Motion or Rett ; receive Motion, in proportion to the Force impreffing it, and refift as much as they are refitted. See Motion.

For the EjfeB of the Vis Inertia; in rejifling and retard- ing the Motion of Bodies, &c. fee Resistance, and Re- tardation.

Vis Impreffa, is defined by Sir I. Newton to be the Ac- tion exercis'd on any Body, to change its State, either of retting, or moving uniformly in a right Line.

This Force confifls altogether in the Action 5 and has no place in the Body after the Action is ceafed. — For the Body perfeveres in every new State by the Vis InertitS alone.

This Vis Impreffa may arife from divers Caufes, as from the Percuffion,Preftion, and Centripetal Force. See Percus- sion, &c. Vis Centripeta. "* /-Centripetal Force.

Vis Centrifuga. ( „ j Centrifugal Force. Vis Matrix. C e ^ Motion. Vis Stimtilans. -J ( Stimulant. VISCERA, in Anatomy, a Term of equal import with Entrails, or Bowels 5 including the Heart, Liver, Lungs, Spleen, Intettines, and other inward Parts of the Body. See Body.

The Word is alfo frequently ufed fingularly, Vifcus, to ex- prefs fome particular part of the Entrails 5 by reafon the Word Entrails has no Singular,

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V I S

The Term Vifcus is pure Latin, being fcrm'd of Vefci, to feed ; by reafon, the Foods, call'd in Latin Vejca, un- dergo divers Preparations in the Vifcera.

VISCIDITY, or Viscosity, the Quality of fomething that is vifcid, or vifcous, i. e. glutinous, or tticky ; like Birdlime, which the Latins call by the Name Vifcus. See Birdlime.

Vifcid Bodies, are thofe which confitt of Parrs fo implica- ted within each other, that they refill a long rime a com- pleat Separation, and rather give way to the Violence done them by ttretching or extending each way. See Particle, and Cohesion.

The too great Vifcidity of Foods has very ill Effects : Thus, Meab, or Faring not fermented, Gellics, &c. of A- ntmals, tough Cheefe, or Curd too much preis'd, produce a Weight or Oppreffion in the Ventricle ; Winds, ifawnings, Crudities, Ob limit ions of the minuter VelTels in the Intef- tines, &c. Hence, an Inactivity of the Intellines themfelves, a Swelling of the Abdomen ; and, hence, a Vifcidity of the Blood, from the re-union of the vijcid Particles 5 Ob- structions of the Glands ; Palenefs, Coldnefs, Tremors, &c.

VISCOUNT. See Vicount.

VISCUS, Viscous, Viscosity, in Anatomy. Sec Vis- cera, and Viscidity.

Viscus, in Natural Hittory, £*?$. See Misletoe.

VISIBLE, fomething that is an Object of Sight, or Vi- fion $ or fomething whereby the Eye is affected, lo as to produce a Senfarion. See Vision.

The School Philofophers make two Kinds of Vifibles, or Vifible Objects : the one proper, or adequate $ which are fuch as are no other way perceivable, but by Sight alone : The other common 5 which are fubject to -divers Senfes, as the Sight, Hearing, Feeling, &c.

Again, the firtt, or proper Objefl of Vifion, is of two Kinds, viz. Light, and Colour ; for thefe two are only fen-

fible by Sight. The firtt and primary, viz. Light, they

make the formal, and Colour the material Object. See

OfiJE-CT.

The Carteftans think they philofaphize better, when they fay, That Light alone is the proper Object of Vifion ; whe- ther it flow from a luminous Body thro' a tranfparent Me- dium, and retain its firtt Name, Light : or whether it be reflected from dpake Bodies, under a certain new Modifica- tion, or Habitude, and exhibit their Images : or, laftly, whether in being reflected, it is likewife refracted after this or that manner ; and affects the Eye with the Appearance of Colour.

But, agreeably to Sir I. Newton's Sentiments, Colour alone is the proper Object of Sight : Colour being that Piopcrty of Light, whereby the Light it felf is vifible ; and whereby the Images of opake Objects are painted on the Retina. See Light, and Colour.

Arifiotle, de Anima, Lib. II. enumerates five Kinds of common Vifibles, which are ufually received for fuch in the' Schools, viz. Motion, Refl, Number, Figure, and Magni- tude : Others maintain nine, as in the Verfes,

Sunt objetJa novem Vifus communia : Quantum, Inde Figura, Locus, fequitur diftantia, fitus, Continuumque ££ Dilcretum, motu'que, cjuiefque.

Authors reafon very variouily as to thefe common Objects of Vifion : There are two principal Opinions among the Schoolmen. — The Adherents to the firtt, hold, That the common Vifibles produce proper Reprcfentations of them- felves, by fome peculiar Species or Image whereby they are formally perceiv'd independently of the proper Vifibles.

But the fecond Opinion prevails mott, which maintains, That the common Vifibles have not any fuch formal pecu- liar Species to become vifible by 5 but that the proper Ob- jects are fufficient to ttiew themfelves in this or that Place or Situation ; and in this or that Diftance, Figure, Magni- tude, &c. by the Circumttances of their conveyance to the Senfory.

In effect, fince thefe common Vifibles cannot be repre- fented alone, (for who ever Taw Place, Dittance, Figure, Si- tuation, ££c. of it felf) but are always convey 'd along with the Images of Light and Colour to the Organ ; what ne- ceffity is there to conceive any fuch proper Images, whereby the common Vifibles Ihould be formally perceiv'd by the Soul ? 'Tis much more probable, that from the peculiar manner wherein the Senfitive Faculty perceives a proper Ob- ject, it is appriz'd of its being in this or that Situation, or Place 5 in this or that Figure, Magnitude, &c. How this is effected, may be conceiv'd from what follows.

I. The Situation and <Place of vifible Objects, are per- ceiv'd without any intentional Species thereof, ?nerely by the Impulfe being made from a certain Place and Situation, either above or below, on the right or left, before or behind 5 whereby the Rays of the proper Vifibles are thrown upon the Retina, and their Impreffion conveyed to the Senfory.

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