THE 



EDINBURGH 



JOURNAL OF SCIENCE. 



Art. I. — Observations on the Vision of Impressions on the 

 Retina, in reference to certain supposed Discoveries respect- 

 ing Vision announced by Mr. Charles Bell. * By David 

 Brewster, LL.D. F.R.S. and St R. S. Ed. &c. 



There is no branch of physical science which has made less 

 progress than that which relates to the optical functions of 

 the eye. Although the phenomena of vision are constantly 

 presented to our consideration, and although experiments 

 without number, and speculations without end, have been ac- 

 cumulated, yet during the last century no prominent discove- 

 ry has been made respecting the physiology of this most im- 

 portant organ. 



It was, therefore, with no inconsiderable satisfaction, that I 

 observed in the Philosophical Transactions for 1823, a paper 

 by Mr. Charles Bell, containing an account of discoveries which 

 promised to throw a new light not only upon the optical, but 

 upon the metaphysical questions which have so long been 

 agitated respecting vision. In studying that paper, however, 

 these expectations have been disappointed. After a careful 

 repetition of the experiments which it contains, and a minute 

 investigation of the phenomena to which it relates, I have no 

 hesitation in stating, that its facts and reasonings are to a 

 great extent incorrect and inconclusive. 



In submitting the results of this inquiry to the Royal Socie- 



* Head before the Royal Society of Edinburgh, December 6, 1821. 

 VOL. II. NO. I. JAN. 1825. B 



