392 Proceedings of Philosophical Societies. [May, 



In this paper the author enters upon an examination of the 

 motions of the eye, and the classification of the muscles accord- 

 ing to their offices. This is done for the purpose of explaining 

 the uses of the six nerves which enter into the orbit, and in pur- 

 suance of his former papers on the nervous system. 



His object in this paper is to show, in the first place, that 

 there are motions performed by the eye not hitherto noticed. 

 Every time the eyelids descend to cover the transparent part of 

 the eye, the eyeball ascends, or suffers a revolving motion. If 

 this were not the case, the surface of the eye would not be 

 moistened, nor freed from offensive particles. He proves, in the 

 next place, that when we fall asleep, the eyeball is turned up, 

 and the cornea lodges secure and moistened by the tears, under 

 cover of the upper eyelid. He shows that these motions are 

 rapid and insensible, and that they are provided for the sale- 

 guard of the eye. The other motions are voluntary, and for the 

 purpose of directing the eye to objects. He then proceeds to 

 the examination of the muscles of the eyeball, distinguishing 

 them, as usual, into the straight and oblique muscles. It has 

 been supposed, hitherto, that both these classes of muscles were 

 voluntary ; some describing the oblique muscles as coadjutors of 

 the recti, and others as opponents to the recti ; but Mr. Bell 

 maintains that the obliqui are provided for the insensible motions 

 of the eyeball, and the recti for those motions which are directed 

 by the will, and of which we are conscious. 



He proceeds to show, that the consciousness of the action of 

 the recti muscles, gives us the conception of the place or relation 

 of objects. He then proves by observation and experiment, that 

 the actions of the straight muscles are inseparably connected 

 with the activity of the retina ; that is, with the enjoyment of the 

 sense of vision : but that the moment the vision is unexercised, 

 the eyeball is given up to the operation of the oblique muscles, 

 and the pupil is consequently drawn up under the eyelid. 

 Hence, the eyes are elevated in sleep, in faintness, and on the 

 approach of death ; aud that distortion which we compassionate 

 as the expression of agony, is the consequence merely of 

 approaching insensibility. 



Having examined the different motions of the eye and eyelids, 

 and the muscles which are appropriated to them, the author pro- 

 mises, in the second part of the paper, to explain on this founda- 

 tion, the distinction in the uses of the nerves of the orbit. 



The Society then adjourned, in consequence of the approach- 

 ing fast and festival, to meet again on 



April 10, when the following paper was read : An Account of 

 an Apparatus on a peculiar Construction, for the Exhibition of 

 Electromagnetic Experiments. By W. H. Pepys, Esq. FRS. 



This apparatus, constructed at the London Institution, under 

 the direction of the author, consists of two plates, the one of 

 copper, and the other of zinc, each two feet wide, and 50 feet 



