Advertifement. )^lie Following Obfer- njations were not written, with Inten¬ tion that they Sbonld he An¬ nexed to the Foregoing Efjay, but to Gratijy a Philojophi- calVhyjician, Which is the Keafon why, bejides tboje things that are more purely Optical , 1 thought fit to mention Some Others, that might be either ZJfiefid or R. Grateful Advertiietnent. Grateful to an Inquifitive Man of his Trofejfon. But having allm'dt he Stationer to Exfe&^that this Boof\^tho' it have for Title but an Eflay, jhsuldnot be of too inconfder- ahle aBull^; I made choice of thefe Papers, among Se veral that lay by tpe, to in- creafe the Bignefs of the Bool\, Becatffe that, the Eyes, being thoje Parts of the Bodies of Men and other Animals, that I pitch’dupon in the Foregoing Treatife, to Strengthen the ThoBrine de¬ liver d in it about. Final Advertifement. Caufes; it feemd Suitable E- nough to my Subject and D^ign, to mention form Vn- common Thingr that related to ZJifion or the Organs of it, that We may be irruitedhoth to Admire the Wifdom of God, which, to furnijh Man with'a Senfe that requires the Concourfe of fo very many things, has, if I may fo fqea\, Qrowded them into fo Small an Engine as an Eye-, and to Celebrate his Goodnefs too, which has been Difflayd in that,notwithfianding that the Eye is fo- very Com- Advertilement. founded a Tart, and the Sight fo eafily Vitiatedyet the moji fart of Men by far do, from their Cradles to their Graves, enjoy the Be¬ nefit and Comfort offo Ne- cejfary and Noble a Senfe. O B S E R V. ; O B S E R V L E xamining a Gentleman, that was already Aknoft Blind, and fear’d to grcKv Altogether fb, about the'^mptoms of his Dileale, ( which came with a Stroke ugpn his Head ) I found, as I ex¬ pelled, by his Anfwers, that, tho’ he could not any thing well dis* tinguifli Objects of Ocher Colors, Yet he could well perceive thole ( 24 ^ ) that were White, to be of That Colour. Which confirms what Tmention in the Hiftory of Colours^ concerning the great Qu^antity af Light, that is RefleOrod by White Objeds, in comparifbn of thofe that are otherwife Golour’cl. And this Obfervation it Self^^as con¬ firm’d by another Patient, who, tho’almoft Blind, coiftd yet dif-, cern White Objeds.^^ O B S E frT. n. " I Knew a Gentleman that had a Cacarad growing,which,when I look’d on his Eye ina lightfcm place, appear’d tO ^Cover aln^li juR the 'Upper Part of the ‘ Pupil; an(;l thp* HC were a,Vo\ing VigO]*G‘ns PeriPn, the Weathef was, ve¬ ry clear,.he could notis^ell. diftetn Men ' f^oin Womfinv xrdfs idre Street. this' Gentlemans Miis- fortune came by a great Stroke tie received ohth at Sid e*;d'f his Head, wher eof hefliew’d m'e the Scar; which ( 2 ^ 7 ) which Circumftance I therefore Note, becaufe when.no Outward Violence has been offer’d to the Eye, it has been obfeived by a good Oculiff:, and, if Imilretnember not, I have Seen an Inftance of it. That a finall Part of the Pupil, left un¬ cover’d by the Catarad, would lerve for^ndfe Sight.than the Gen¬ tleman enjoy’d. In him like wile I had a further Confirmation , of what I was lately Obferving about the Conlpicuoulnels of White Ob* jeds. For tho’ he could not, as I was faying, difeern Men and Women that pafs’d by, on the o- ther Side of the Street, yet, having once defired him to tell me, if he could diftiriguilh any Objed there, he told me that he could and th^t I might no longer Doubt of it, when I asked him what he faw, he faid that it was a Woman that pafs’d by with a White Apron, which Apron he faw diredly, and therefore jmight eafily con¬ clude, without diftindly feeing the R 4 * Wearer, ( ) Wearer, that the Perfon that Wore it was a Woman. O B S E R V III. M Eeting accidentally with a Man, by ProfefTion a Far¬ rier, whofe Eyes look’d very odly, I queftioned him about hisDiftem- per; and found by his anfwers, that he had had Catarads in both his Eyes, but either had them ill Couch’d, or had not behaved him- lelforderly afterwards. For there Seemed ftill to be ragged Filnis, that cover’d conliderable portions of his Pupils; in fb much that I fom- what wonder’d to fee him go free¬ ly about, as he did, without requi¬ ring any body to help him,fb much as up or down Stairs: and I hereupon asking him, whether he were able to Read in a large Print, he told me he was,with the help of his Catara^f Spe^acks,2is they call them,which I doubting of, brought him a Book, whofeTitle Page he was not able to Read ( 249 ) Read; this he Excus’d by faying that the place was too Lightibm, which tho’ it did not Seem to O- tiiers, yet, confidering that it was about Noon, I caus’d the Room to be a little darken’d, and then per¬ ceived that indeed he could Read ^ well Enough. O B S E R V. IV. Gentleman, having in a quar¬ rel receiv’d a Stroke on one Side of his Head, which knock’d him down, found afterwards a great Weaknefsand dimnefs in his Eyes'; into which when I look’d atten¬ tively, I plainly dilcern’d, that M above one half of his Pupil was yet uncover’d, fb that when he look’d downwards, he could See well e- nough with That Eye, yet there was grown in it no left than two Ca * tarafts, which, when I look’d on them attentively, and in a good Light, I could manifeftly perceive to be Diftind ; the One of them feeming ( i5o ) leeming to be fmooth f pread, as if its Circular Edge adher’d clofely to the infideof the Eye,*and the Other, that ieem’d not altogether of the lame Cobur, hanging ioofely, and as it were* a Rag, at fbme diftance above it. What afterv/ards be^ came of this Cedtleman I could not learn, tho’ I would gladly have done it; TwoCatarafibs at a time in one Eye being Tome what Extraor- . dinary, O B S F R V. V. A Learned Gentleman- coming hnce to vifit me, with defign, ' as I affierward’s perceive’d, to hear my OpidionGoncerning an odd DiL temper hej bad in his Eyes; I found, byJDifcoutiihg with him concer- nirig the of his Dileafe, that ti'a’i^.'when he lookM onOb- • at hand, he Saw them - ibmewhat 1])imlyj but yet Single, there; Wore fome Objdds, par- tiealaiiy* Pods and Rails, which, ^ 'i- when (251 ) when he beheld at a certain di- ftance ( which was not very great) they appear’d to him both more Dark and Double. I found allbthat he complained of divers Black Flyes and litle Leaves, that pafs’d now and then before his Eyes ; which, tho'^ they do not always fore^bode a True Catara£f, fince Others and I alfo hav^ oblerv’d them to continue many years without being more than a Bajiard as Bhy- ficians Speak e ) jet in him they were probably Forerunners of a True Gatarad; in regard that I have known it obferv’d by a skil¬ ful Oculift, that fome Perfons, be¬ fore their Gatara£l:,have complain’d that at fome Diftances they law ObjeQis almoft Double; ib that loo¬ king at ones Head, they thought they Saw a great part of a Dark Head a little above it: which De^ Icriptiori,whether it proceeded from fome Refra£lions made by the yet not OnifbriBiy Opacous Matter of the Gatarad , not having oppor¬ tunity (aja) tunity to examine thofe Perfbns my feif, I dare not Venture to fay. O B S E R V. VI- I T may be worth Obferving, How long The better fort of Ca¬ taracts, tho^ they hinder Sight for a time, as a thick Curtain drawn crofs the Pupil, yet may remain in the Eye, without Spoiling the Optic Nerve or hindringVihon when once the CataraCt is removed; Of which I remember, among Other Inftan- ees, I took notice in the Cafe of a Woman, who told me fhe had Ca- taraCts in her Eyes fo long, that fhe was brought a Bed of Sm Chib dren conieeutively, without being able to Sse aay one pf theni, till after fhe was Cur’d by having the Catarads Couched. But then fhe law lb . well; that with SpeCllacks fhe could read in a portable Bible of a fmall Print. And divers confi- derable Perfons of my Acquaintance law One iQf Eighteen years Old, born ( 353 ) born with Catarads in both her Eyes, Who not naturally Wanting the Faculty of Seeing,tho’ thus Hin¬ der’d of the Exercife of it, had been fo happily Couched, as afterwards to have the benefit of Sight in them both. • O B S E R V. VIL I Tbasteen of late the Opinion of very Learned men, that tho Both obr Eyes be Open and turn’d towards an ObjeiEt, yet ’tis but One of them at a time that is effeaually Imployed in giving us the Repre- fentation of it. Which Opinion, in this place where I ar» writing but Obfervations, it were not proper to Difcufs; efpecially becaule what is fuppos’d to be Obferv’d, w ill not always Uniformly happen, but may much Vary in particular Per^ fbns, according to their feveral Cuftoms, and the Conftitution of their Eyes. For I have, by an Ex¬ periment purpofcly made, feveral times (M4) tiiries found, that my Two Eyes Together fee an Objed in another Situation , than Either of them Apart would do. On the other fidej I met with a Perfbn, who told me he had a Catarad in his Eye for two Years, without dilcer-r ning that he had any fiich Impedi¬ ment in either of his Eyes; and when I ask’d him, how he knew that, he aniwer’d me, that others had taken notice of a white Fiinap thatcrols’d his Eye, fb long before he himlelf did. But not knowing what aCataradwas , and not find¬ ing himto complain of it at all him** felf, the Thing remain’d unheeded, till the Patieat, having one day cc* cafiori to hub his Sound Eye, whilli: the Lid cover’d it, was (adly Sur¬ priz’d to find himfelf altogether in the Dark ; and then reforting to anOculifi, was afiur’d it was a Catarad, which, a while before I met with him, had been Couch’d." But notwithftanding this Relation, what I had try’d about the Ufing (^? 5 ) of Both Eyes, made» me ask of a very Ingenious Perfon, that by an Accident h^d Ibme months before one of his Eyes ilmck out, whether he did not obferve, that upon the being confin’d to the ufe of One Eye he was apt to milfakethe Situati¬ on and Diftances of things. To yvhich he anfwer’d me, that have- mg frequently occafion to pour Diftill’d Waters and other Liquors out of one Vial into an other, after this Accident he often Spilt his Liquors, by pouring quite Befides the necks of the Vials he thought he was pouring them diredly Into. Afterwards inquiring of a Gentle- was a Goodfellow, and had by a Wound a while before loft the ufe of One of his Eyes; he confels’d to me, that divers times pouring the Wine out of one Veflel into another , he would mift the Orifice of the Bottle or Glafsthat Ihould receive it, and expole him- lelf to the merriment of the Com¬ pany. A yet more confiderable In- ftance (i’ell, IS never without Pain in it; W looking into her Eyes, I per¬ ceived nothing Amils, yet conieftu- ringthatfoGbftinate aDiftemper mull (Vo) muft have had fbme Unufual Influ¬ ence upon her Sight; I learn’d by Inquiry that after theViolent Fits of Pain and Difbrder fhe had from time to time in her Head, if fhe did but caff her Eyes, or turn therh fuddenly,from one fide to the other, there would prelently enfiie aCon- vulfivc Motion in One of them, whexebyit would notdnly bedrawn away, but, which was Very ftrange. All White Things, and mofl: other Objedls, that fhe look’d on with that Eye, appear'd Green to her: And yet this was not a Tranfient Difcompofure that would go quick¬ ly off, but would Molefl: her for a good while^ and frequently Return’d upon her for a whole year; fb that fhe difpaired of Recovering the ufe of that Eye, vvherevvitH yet fhe now fees very well, tho’ her Gephalick Diftempers vvete rather Mitagated than quite Cur’d. And when I ask'd her, whether,^ vvhilefl: theCOnvulfion of her Eye Hfted, fhe did not fee Gbjeds Ddu • (^71 ) ble? She anfvver’d, that whiled that Diftemper was upon her if iiie went to Read in a Book, the Letters were fo apt to appear Dou¬ ble, that when/he was bent upon Keying, /he vyas fain to /hut the Di/tempefd Eye, and Imploy only « the Other. ■' ^ OBSERV. XIV. S ome may think that a'Man has rather an Exc«llent,than a Viti¬ ated Sight, who can See Oftieds with a far lefs degree of Light thaa other Men have need of to Difcera wem. But tho’an Extraordinary TMdernefsmaybe a kind of Per- /edion m the Eyes of Bats and Owls, whole uiual Food may be more ea- lily Purcha/ed by Twilight: Yet as to Man, the main part of whole AcEions is to be perform’d by the Light of the Day, or fonie other almoft Equivalent; it may Argue the provident goodnefs of the Author of Nature, to have given Him Eyes Conftituted as thofe of Men ( 172 ) Men generally are : Since, That a very great Tendernefs of th^Retina, or principal part of the Organ of Sight, would be, if not an Imper- feQ:ion, at leaft a great Inconve¬ nience, may appear by the Memo¬ rable Story lam going to Relate. In the Army of the late King of Hapy Memory, (^Charles the Firft ) there was a Gentleman- of great Courage and good Parts, that was Major to one of the Regiments ; who being after¬ wards by the prevailing Ufurpers forc’d to leek his Fortune abroad, ventur’d to do his King a piece of Service at Madrid, which was of an Extraordinary Nature and Confe- quence, and there judg’d very Ir¬ regular. Upon this he was com¬ mitted to an Uncommon Prifon, which, tho’ otherwife Tolerable e- nough, had no \yindow at all be- longing to it, but a Hole in the thicknels of the Wall, ^at which the Keeper once or twice a day put in (273 ) in liberal provifion of Viduals and Wine, and prelendy Clos’d the Window , if it may be fo call’d, on the Out-fide, but not perhaps very Solicitoufly. For Ibme Weeks this poor Gentleman continu’d in *the Dark, very Dilconlblate. But afterwards he began to think he o faw fbme little Glimering of Light, which from time to time Increaled; infbmuch, that he could not only Difcover the Parts of his Bed, and other fiich large Objeds, but at length came to Difcover things ,fo Minute, that he could Perceive the Mice that frequented his Cham¬ ber, to eat the Crumbs of Bread that fell upon the Ground, and Pifcern their Motions very well. Several other Effects of his Sight in that Dark Place He Related. /Sid that which Confirms that this Pro¬ ceeded mainly from the great Ten- dernefs the Vifive Organ had acqui¬ red, by fb long a Ray in fb Obfcure a Place, was, that when after'fbme Months, the Face of Affairs Abroad T being ( 274 ) being fomwhat. Chang’d, His Li¬ berty was reftor’d him, he durft: not leav'e his Prifon Abruptly, for fear of lofing his Sight by the Daz- ling Light of the Day; and there¬ fore was fain to Accuftom his Eyes by flow degrees to the Light. This Strange, as well as once Famous Story,I the lefs Scruple to fet down in this Place, becaufe’ I had the Curiofity to learn it from the Gent- tleman’s own Mouth, who acquain¬ ted me with other Particulars about it, that, for want of the Notes I then took, I fliall not now venture, to fpeak of. F I N I s.