V 1 s 



V L S 



He {hews that objefts may be feen with fufficient diilind- 

 nefs, thoucrh the pencils of rays ifTuing from the points of 

 them do not unite precifely in the fame point on the retina ; 

 bnt that fince, in this cafe, pencils from every point, either 

 meet before they reach the retina, or tend to meet beyond 

 it, the light that comes from them muft cover a circular 

 fpot upon it, and will, therefore, paint the image larger 

 than perfeft vifion would reprefent it. Whence it follows, 

 that every objeft, placed either too near, or too remote for 

 perfeft xnVionJ will appear larger than it is by a penumbra of 

 light, caufed by the circular fpaccs, which are illuminated 

 by pencils of rays proceeding from the extremities of the 

 objeft. All the varieties occafioned by this circumftance 

 he traces with great accuracy, and he applies his obfervations 

 \ipon it to the explanation of many phenomena in vifion. 

 See C/ir/f ff/" Dissipation. 



Dr. Jurin obferves, that when objefts are large, they 

 will appear tolerably diftincl at a much lefs diftance than 

 fmall objects, becaufe the penumbrx will not interfere fo 

 much ; and on this account, a large print may be read much 

 nearer to the eye than a fmaU one. In this cafe the former 

 will appear only ill defined, but fufficiently dilUnft, when 

 the latter is quite indiftinft, the penumbra of one letter 

 interfering with that of another, and thereby making maiks 

 altogether unhke any that are in the book. The difperfed 

 Lght of thefe penumbra?, he fays, is of different denilties ; 

 and Mr. Robins, in his Remarks on Dr. Jurin, p. 279, ob- 

 ferves, that the whole circle made by the confufed image of 

 any print, will be proportioned to the diameter of the pupil 

 of the eye, which limits the whole pencil. 



The fmalleil diltance of perfeft vifion, or that in which 

 the rays of a fingle pencil are coUeAed into a phyfical point 

 on the retina in the generality of eyes, Dr. Jurin, from a 

 number of obfervations, ftates at five, fix, or feven inches. 

 The greateft diftance of diftinft and perfecl; vifion he found 

 to be more difficult to determine ; but by confidering the 

 proportion of all the parts of the eye, and the refraftive 

 power of each, together with the interval that may be dif- 

 cerned between two ftars, the diftance of which is known, 

 he fixes it, in fome cafes, at fourteen feet five inches, though 

 Dr. Porterfield had confined it to twenty-feven inches only, 

 with refpeA to his own eye. 



When vifion is indiftinft, Dr. Jurin thinks that there are 

 two methods of rendering it diilinft. One is for the eye to 

 apply the fame power, by which it conforms itfelf to the 

 view of objects placed at different diftances, fo a? to obtain 

 perfeft vifion ; and the other is the contraction of the pupil 

 by the leffer mulcular ring of the uvea, which is chiefly 

 made ufe of in a ftrong light, and which will fometimes 

 render the other means altogether unnecefTary. In a weak 

 light, he fays, the pupil is fo far fi'om contrafting, that 

 there is rather a neceffity for dilating it, to take in more 

 light. But upon this Dr. Whytt (Eff. on vital and in- 

 voluntary Motions, p. 133.) obferves, that in the fame, or a 

 lefs degree of light, the pupil will be contrafted, in order to 

 view a nearer or a fmaller objeft. For other obfervations 

 on this fubjeft, fee Jurin's Eff. on d'ftinct and indiftinft 

 Vifion, at the end of Dr. Smith's Optics ; and Robins's 

 Remarks on Dr. Jurin, in his Math. Trafts, vol. ii, 

 p. 278, &c. 



Vision, FielJ of. See Field. 



Vision, among Dl-v'tnes, is ufed for an appearance, which 

 God occafionally fent to his prophets and faints ; eitiijer by 

 way of dream, or in reality. 



Such were the vifions of Ezekiel, Amos, &c. ; the vifion 

 of St. Paul, lifted up to the third heaven, &c. ; of Jofeph, by 

 v.'hich he was affured of the purity of the Virgin, S:c. 



Some have reprefented our blcffed Lord's temptation 'm 

 the wilderncfs, Matt. v. i, &c. as a vifion. Mr. Farmer, in 

 particular, confiders it as a divine vifion, reprefenting the 

 trials he was to endure, and defigned to prepare him for 

 encountering and vanquifhing them. See Temptation. 



Many among the Romifh faints have pretended to 

 vifions : as St. Therefa, St. Bridget, St. Catharine de 

 Sienna, &c. 



Hence the word has come into difrepute, and become a 

 common name for all chimeras, or fpeftres, which either 

 our folly or fear pofTefies us wvh : and hence, a pcrfon tlial 

 frames to himfelf wild romantic notion?, is called a v'lfionary. 

 Quevedo's Vifions are defcriptions of what pafled in the 

 imagination of that author. 



Vision, Beatific, denotes the aft by which the angels and 

 blefled fpirits fee God in Paradife. 



VISIR, VisTEK, or Vizier. See Visier. 



VISITATION, VisiTATio, an aft of jurifdiftion, by 

 which a fuperior or proper officer vifits fomc corporation, 

 college, church, or other public or private lioufe, to fee that 

 their rcfpeftive laws and regulations be duly obferved. 



Among us, the bilhop of each diocefe is obhgcd to hold 

 a vifitation every third year, and the archdeacon the other 

 two years ; to fee that the difciplinc be well obferved, the 

 people well inftrufted, and to take care that neither the 

 church, nor the paftors of it, receive any detriment. For 

 the firft 600 years atter Chrift, the bilhops in their own 

 perfons vifited all the parifhes within their reiptftive diocefes 

 every year ; but fince the law and praftice of triennial 

 vifitations have been eftabliflied, the bilhop is not only not 

 obliged by law to vifit annually, but he is reilrained from it. 



The bufinefs of parochial vilitation, in order to infpeft 

 and take account of the fabrics and manfions, ornaments 

 and utenflls, vcftments and books of the church, peculiarly 

 belongs to the archdeacon. In all vifitations of parochial 

 churches made by bifhops and archdeacons, the law hath 

 provided, that the charge of them fhall be defrayed by the 

 procurations then due, and payable by the inferior clergy ; 

 'in which cuftom, as to the quantum, fhall prevail. Thefe 

 procurations are due to the perfon vifiting of common 

 right ; and although originally due by reafon of vifitation 

 only, yet the fame may be due without aftual vifitation. 

 They are fuable only in the fpiritual court, and are merely 

 an ecclefiaftical duty ; and they may be levied by feq«eftra- 

 tion, or other ecclefiaftical procels. Free chapels and 

 donatives (unlefs fuch donative hath received the augmenta- 

 tion of queen Anne's bounty) are exempt from the vifitation 

 of the ordinary, and of courfe pay no procurations ; the 

 firft being vifitable only by commiffion from the king, and 

 the fecond by commifliion from the donor. And there are 

 alfo other churches and chapels exempted, which belonged 

 to the monafteries ; which by 25 Hen. VIII. c. 21. were 

 made vifitable by the king, or bv commiffion under the great 

 feal. 



Anciently the regarder's office was exprefled to be the 

 •vifitation of manners. See Regarder. 



The lawyers hold it a branch of the king's prerogative, 

 to vifit the univerfities ; to enquire into the ftatutes, and 

 the obfervation of them ; to expel delinquents, &c. But 

 fome of the colleges difallow this privilege, and plead them- 

 felves, by royal chai-tcrs, exempt from all civil and royal 

 vifitations. 



With regard to all ecclefiaftical corporations, the ordinary 

 is their vifitor, fo conltituted by the canon law, and thence 

 derived to us. The pope formerly, and now the king, as fu- 

 preme ordinary, is the vifitor of the archbifhop or metro- 

 politan : the metropolitan has the charge and coercion of all 

 8 his 



