( 267 )- ' 
gether with the l^erves upon which Account there may 
be as true a fence of Light in them as there is of Pain 
ia the hand ("which is alfo full of llood Vejfels ) ssY.tn 
it is prickt with the point of a Needle; and perhaps the 
prefence of Veins and Arteries in a member, is abfolutely 
neceflary tofenfibility. The blacknefiot the Cboroide may 
make its nicenefs of fence, as we fee Paper blackt eafieft 
fires. He fays the Choroide does communicate wirh the 
Optickj^erve:^ by which l^erve he does not underftand the 
Marrow^ or inner part of it, which is infenfible; but the 
Membrane (being part of the Tia mater) which incompaffes 
it, and is the true Organ offence not only in the E'je> but al- 
fo in the Ear whereas the Marrow of the Nerves contain 
only fpirits and liquour ufcful to motion. 
To the Third head , where Mr. Perault gives reafons 
why there is no Vifion upon the Bafe of the Optic}^ Nerve, 
as firft fuppofing that Vifion is to be made on a fmooth 
furface, the Optici^ Nerve which is a bundle of Fibres is 
not fmoothe'd at its firft entring the l{etina> but after- 
wards when the Fibres are diffolved, and fpread into a Coat, 
as when Rags are made into Paper. 
Here Mr. Manotte (\{ I rightly comprehend him j de- 
nyes the i{ettnas confifting oi Fibres \ affirming it to have 
nothing but a Mucoufnefs with fome Veins and Arteries. 
But if I am not miftaken fin an Experiment of Dr.^n^^j's, 
^K^tina ^nt into a Glafs of fair Water , and drawn about 
under Water, both for the Expanding and Magnifying it> 
appeared plainly to have a fibrous texture* like that of a 
pieceofvery fine Lawn. 
In the Second place 5 Mens /^^W/^ fuppofes that the 
Choroide being pierced by the Optick^ Nerve y there may 
come a light thro the parts ot the Eye, the back way. in" 
to x\itOpticJ{Nerve,wh:\c\\ would fpoyl iht fenfe of another 
light coming thro the F///'//. 
But this Mr. Uariotte will by no Hieaas agree too. 
fJiJkria 
