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An Observation 
Concerning d Blemilh in an Horfes Eye, not hitherto iif cover'd by 
any Author % which may he of great u[e in the Choice of an 
Horft ? to thof e who are Curious % made by Dr, Richard Lower 
- at the Royal Society , January 23. i66\ a 
: A Mong the many defeds and diflempers in the Eyes, the Eyes 
x\ of Horfes are peculiarly affeded with one, which no Ani- 
mal befides is troubled withall f as far as I have obferv’d.) nei- 
ther do I remember any Author hitherto to have taken notice of 
it 1 and that is a Sfungy Excrescence (commonly of a dark muske- 
colour ) which grows out of the edge of that Coat of the Eye 
call'd the Vvea^ which Spungeif it grow large or increafein 
number ( as it frequently happens ) it depraves the fight very 
much, or totally intercepts it„ But that you may more eafily con- 
ceive the manner,how it is done, you may remember,that the Uvea 
is a mufculous part,the ufe of it being chiefly to contra# and dilate 
i t felf for theadmiflion of Objects with as much light, as the 
Eye can conveniently bear *, fo that, the brighter and more 
refulgent the light is, to which the Eye is expos’d, that Mem- 
brane contra&s its felf into a narrower compafle 5 and the more 
dark the place is, it delates it felf the more, as you may fee in a 
Cats eye more readily perform’d, than in any other animal , I have 
yet obferv’d : So that, if that fyungy fubftance, which growes out 
of the edge of the Uvea> be fo greater the number of them fuch, 
as that they grow in feveral places about the fupll of the Eye, 
where it contrads its felf, th epfill or fight is very much (if not 
totally) obftruded, and confequently the Hoife fees very little 
or nothing at all: As I have many times taken exa# notice in 
feme Horfes, which being brought into the Sun-fhine, could not 
fee atall, but fuffer’d me to touch the fight of their Eye with my 
finger without the lead winking-, which Horfes being led back 
into the Stable, the Uveain that obfeure place dilating it -felf, 
they could fee very well again, and would not fufiferme toihew 
my finger near to the Eye without frequent doling their Eye- lids 
and tolling their heads. T he fame Horfes 1 underload by the 
J T tt Owners 
