Class II. i. 4. i. OF SENSATION. 219 



fymptom of fcrofula, when it recurs frequently in young per- 

 fons ; but is probably only a concomitant of that difeafe, as a 

 fymptom of general debility j ramifications of new red vefiels, 

 and of enlarged old ones, are fpread over the white part of the 

 eye ; and it is attended with lefs heat, lefs pain, and lefs intoler- 

 ance of light than the ophthalmia interna, dcfcribed in Clafs II. 

 1.2. 2. It. occurs in thofe of feeble circulation, especially chil- 

 dren of a fcrofulous tendency, and feems to arife from a previ- 

 ous torpor of the vefiels of the tunica albuginea from their being 

 expofed to cold air ; and from this torpor being more liable to 

 occur in habits, which are naturally inirritable ; and therefore 

 more readily fall into quiefcence by a fmalier deduction of the 

 itimulus of heat, than would affeA ftronger or more irritable 

 habits ; the confequence of this torpor is increafed action, which 

 produces pain in the eye, and that induces inflammation by the 

 acquisition of the additional fenforial power of fenfation. 



Ophthalmia lymphatica is a kind of anaiarca of the tunica adna- 

 ta ; in this the vefiels over the fcierotica, or white part of the 

 eye, rife considerably above the cornea, which they furround, are 

 lefs red than in the ophthalmia fuperficialis, and appear to be 

 f welled by an accumulation of lymph rather than of blood ; it 

 is probably owing to the temporary obftruclion of a branch of 

 the lymphatic fyitem. 



M. M. If the pain be great, venefeclion by leeches on the 

 temple, or cutting the temporal artery, and one purge with three 

 or four grains of calomel lhould be premifed.. Then the Peru- 

 vian bark twice a day. Opium from a quarter to half a grain 

 twice a day, for fome weeks. Eathe the eye frequently with 

 cold water alone, or with cold water to a pint of which is added 

 half an ounce of fait. White vitriol, fix grains diiTolved in one 

 ounce of water ; a drop or two to be put between the eyelids 

 twice a day. Take very fmall electric fparks from the eyes eve- 

 ry day for a fortnight. Bathe the whole head with fait and wa- 

 ter made warm, every night, for fome months. Send fuch chil- 

 dren to a fchool near the fea, for the convenience of fea- bathing, 

 for many months, annually j fuch fchools are to be found in or 

 near Liverpool. 



When a child is afflicted with an inflamed eye of this kind, 

 he lhould always fit with his back to the v/indow or candle ; 

 but it is generally not necefiary to cover it, or if the uneafy fen- 

 fation of light makes this proper, the cover mould ftand ofir from 

 the eye, fo as not much to exclude the cool air from it. As 

 covering an eye unnecefTarily is liable to make that eye weaker 

 than the other, from its not being fufficiently ufed, and thence 

 to produce a fquinnng forever afterwards. 



Neverthelefs; 



