[ *3 ] 
a clearer Sight of the Objed, than if held right 
before them at equal Diftances from both Eyes $ 
becaufe the AdduElor of each Eye is violently drain'd 
and contraded, in order to draw both Pupils to the 
Object, which is troublefome ; and it is only in this 
Cafe that thefe two Mufcles ad together as Antago- 
nifts to the two AbduEtars, and bring them to 
fquinting ; whereas, when the Objed is held a 
little Edeways; tho’ the Pupil is brought near the 
Nofe on one Side, that of the other will be carried 
in fome meafurefrom it on that Side towards which 
the Objed is held, and thereby the proper Mufcles 
will ad together $ that is, the AdduElor on one Side 
will ad in Concert with the AbduElor on the other, 
and vice verfa , altho* not fo perfedly as when the 
Convexity of the Eyes is more natural. The fame 
fquinting Diftortion will happen to any one who 
places an Objed too near his Nofe. Now the Rea- 
fon why the Pupils of the Eyes mutt follow one 
another in viewing Objeds, is, becaufe the Mind 
can attend to no more than one Objed at a time 
and fnce one Eye cannot difcern fo well as both 
together, let the Objed be placed where it will, 
thofe Mufcles, whofe Contractions ferve to condud 
both Pupils towards it* are only employed by the 
Will : And hence it is, that the AbduElor s can ne- 
ver both ad together according to the Will, for one 
Eye in that Cafe would be intirely ufelefs, and the 
Afped of the Perfon unnatural and unfeemly be- 
fides. Arijlotle , in his third Sedion, and firft Pro- 
blem, makes a Query, why the Eyes ad together ? 
and anfwers, That it is becaufe the Motion of both 
has one and the fame Principle, which is, fays he. 
