( '^31 ) 



In Plate VIII; i^t fig. 2, i.s reprefented the i'urface of the cr3'ftal- 

 line humour, pidlured at Jig. i, but, wh/icii is here to be confidered, 

 a« if that figure did prefcat a circular fhapc to tlie eye. Jii this 

 figure, are many lines to reprefent the courle or direflion of the 

 filaments, but, it mult not be fuppofed to give a true reprefcntation 

 of their numbers, the circumference of the cryftalline humour of 

 an ox's eye, containing more than twelve tiioufand of fuch fila- 

 ments. For, ten of thele filaments laid fide by fide are, (as before 

 obferved) jiot equal to the diameter of an hair ; and the v%hole axis or 

 diameter of the cryflalline humour being, as before noted, equal to 

 four hundred hair's brcadtli, it confifts of four thoufand filaments in 

 diameter. And, by the common rules of arithmetic, whereby we find 

 the circumference of a circle, of a given diameter, it will be found, that 

 the circumference of the cryftalljne humour in an ox's eye, confifis of 

 12571-^ filaments. 



Hence we may collefl, how exceffively thin thefe filaments are; 

 and, ^ve fhall be firuck with admiration, in viewing the %\onderful 

 manner they take their courfe, not, in a i-egular circle round the ball 

 of the cryfialline humour, as I firll thought, but, by three difterent 

 circuits, proceeding from the point L, which point, I will call their axis 

 or center. They do not, on the other fide of the fphere, approach each 

 other in a center like this at L, but return in a fhort or fudden turn 

 or bend, wjiere they are the fliortefi:, fo that, the filaments of which 

 each coat is compofed, have not in reality, any termination or end. 

 To explain this more particularly, the fliortefi: filaments MK, HN, 

 and OF, whicli fill the I'pace on the other fide of the fphere, conftitutc 

 a kind of axis or center, fimilar to this at L; lb that, the filaments 

 MK, having gone their extent, and filled up the fpace on the other 

 fide, in like manner as is here lhev>n by the lines ELI, return back, 

 and become the Ihortelt filaments, HN. Thefe filaments HN, paf- 

 fing on the other fide of the fphere, again form another axis or center, 



