Mr. Smith on the Muscularity of the Crystalline Lens. 5 



ing with lime-water. In this vessel was placed a glass dish, 

 containing an ounce of finely pulverized charcoal. The char- 

 coal was left to stand in the oxygen for 24 hours ; and at the 

 expiration of that time no trace of carbonic acid was to be 

 found on passing the remaining gas through lime-water. 



This experiment was three times performed in the same 

 manner, and with precisely the same result. 



I have here given a brief and simple statement of the ob- 

 servations and experiments which I have yet made upon this 

 curious and interesting subject. The spontaneous combustion 

 of charcoal is, I apprehend, now fully established; and I have 

 endeavoured, to the best of my ability, to determine some of 

 the circumstances under which it takes place. I have abstained 

 from any theoretical speculations ; contented, for the present, 

 to have related the facts which experiments alone have eli- 

 cited. If in future any new facts should present themselves, 

 I shall be happy to submit them to the Society. 



II. On the Muscular Structure and Functions of the Capsule of 

 the Crystalline Lens and Ciliary Zone. By Mr. Thomas 

 Smith, Surgeon, Fochabers*. 



TTAVING found by observations on the eyes of the three 

 *-*■ principal classes of animals, that the capsule of the cry- 

 stalline lens, and the radiated circle of the hyaloid membrane 

 to which it is attached, are endowed with a fibrous structure 

 and contractile property which admirably fit them for chang- 

 ing the figure of the lens, by rendering it more or less spheri- 

 cal ; and that the optical phsenomena attending the accom- 

 modation of the eye to different distances, as well as certain 

 changes which the lens itself is found to undergo, correspond 

 in a singularly happy manner with those which ought to result 

 from the functional action of the capsule as the organ of ad- 

 justment, — I venture, in compliance with the advice of some 

 intelligent friends to whom my observations have been sub- 

 mitted, to offer an account of them for publication ; for though 

 the induction from the phaenomena is not in certain respects 

 so complete as I have been anxious to make it, yet I trust it 

 may be found sufficiently so to vindicate me from the charge 

 of presumption in directing into this new channel the attention 

 of persons better qualified than I can pretend to be, to carry 

 it to perfection. 



The extreme transparency of the capsule of the lens in its 

 sound state renders its structure difficuit to be ascertained by 



* Communicated by the Author. 



