5# J Continuation of a Tyifcourfe ahaHt Vifi- 
on, mth an Examination offome Ute Oh^ 
(eBions againfi it. V Villiam Briggs 
M. D. and FeMow of the College of 
Phyfitians. 
LJAviDg formerly given a * Specimen of my thoughts a- 
* ^ bout Vtfiom I purposed to defer the publifhingany 
thing more relating to it^ till a more entire Treatife^zbom the 
Particular ufes (f the parts of the Eye inVifion) had been 
fini(hr> which I intimated my defigning at that time s but 
this will require the confiderarion of many more years, and 
indeed the Subjeft is fo admirable, and may be of fuch ufe 
to convince the Scepticifmoi the age, that I hope it will not 
fee time loft : and if I have fufHcient opportunities* or be 
affifted with theprafkcal Ohfervations of others whom I dare 
confide in, I may perhaps add withall the Patholo^ of thzt 
Vfeful parti to make it the more acceptable to the World. 
In the mean time f have been prevailed with to make thi 
i«Air^^;w^;2)^cf the forementioneddifcourfe* in order to the 
fuller expla my thoughts^ and the clearing fome diffi- 
culties which have been propounded againft it. 
In that fmall Eflay I endeavoured to fliew. That the 
fbres ofihtOpHc Nerve, as rifing from the two protube- 
rances of the thalarniOptici^ were more concerned in VifiofI 
then either the Cornea> Humours^ or Patina fas they are 
confiderdby Writers in O/^^rj-;. not only becaufe/^//^jf^o« 
(a) In Mr. Hook*^ f^M* Colk&lm tf. 
Z 2 
is 
