conclude that if the Retina were the Organ of fight, this dog 
would noc lee the objefts indilferently inlightned, which arc 
about the candle, although at 3 or 4 foot diftance, bccaufe they 
would receive a great deal more imprefifion from this reflexion, 
and that a great fonfation doth obliterate a leffer 5 which is con- 
trary to experience^and it is not at all likely,there fliould be fuch 
a defeft in the fight of Animals, 
The third is,that the Eyes of Birds are fo framed^that the Op- 
tique nerve after its infertion into the Eye is infleftedj and ex- 
tends it felf on the Concavity of the Sclerotis about the breadth 
of 2 or 3 lines more or lefs according to the bignefs of the Eyes; 
and the length of thfs inflection is covered by the Chorocides^ lea- 
ving but one little white ftreak in the middle, from whence the 
^ainA takes its Original, which extends it felf on the Choroeidcs 
through all the bottom of the Eye, but it is covered on the fide 
of this white ftreak with a little black membrane as long as the 
inflexion of the nerve^and almoft as broad > which proceeds from 
the f ia mater ^ and is as it were an sppendixof the Cheroeides : 
and if you confider the fituation of this membrane, ycu will find 
it is near the Axis of fight, and that the rayes of thcObjedts, 
which the Birds look on with both Eyes, falj precifely upon it 
after their refraeiion. Since then in the place , where Vifion 
ought to be ftrongeft, the Retina is covered, and that no man 
doubts bur Birds are more clear- fighted than other Animals vyou 
ought to acknowledge, that the Retinaismt the principal Or- 
gan of Vifion , but that that preeminence belongs to the cho- 
roeides, 
AN ACCOMPT 
Civin by jD^<5?^?r Edward Brown, concerning th^ Cc^per-mint 
at HQnn'§^tomd in Hungary, 
HErrn-grottnd is a little townjeated very high between imy 
Hills, upon a part of land of thefamename, anHungafri- 
4in mile diftant from Netvfol, In this town is the entrance in^ 
a large Copper-mine, very much digged. : : • j 
Iwtntin throughaC«;^/V/?^/^^, called Tach-ftfih^ and con t4- 
Bued divers hours in the Mine, and vificed many of thenioft m- 
markablc 
