THE 



LONDON AND EDINBURGH 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[THIRD SERIES.] 



OCTOBER 1832. 



XLVII. Livestigation of certain remarkable and unexplavied 

 Phcenomena of Vision^ in ixhich they are traced to Functional 

 Actions of the Braiii. By Mr. Thomas Smith, Surgeon^ 

 Fochabers *. 



OOME years ago I published in this Journal f an account 

 *^ of a remarkable affection of sight which I had discovered 

 accidentally while engaged in a course of experiments on the 

 apparent luminousness of objects, and which was thought the 

 more worthy of being recorded, that it could be easily pro- 

 duced in others as well as in myself, by placing the two eyes 

 in certain relations to light. 



My former communication having been limited to a mere 

 announcement of the new facts I had observed, I propose, in 

 this paper, to state the results of the attempts which I have 

 made, since that period, to discover the causes of the phaeno- 

 mena. These results might be mentioned in a few words ; but 

 as the subject is, in almost all its bearings and relations, en- 

 tirely new, and as the conclusions to which 1 have been led, 

 tend, if confirmed, to throw a very unexpected light on the 

 nature and exciting causes of cerebral Jitnction^ of the laws of 

 which so little is known, I have thought it incumbent on me 

 to give each particular 5>tep of the investigation in detail, to 

 enable the reader who takes an interest in the subject, to judge 

 how far the conclusions are borne out by the premises. Our 

 total ignorance of the proximate or immediate causes of per- 



• Communicated by the Author. 



+ See Edinburgh Journal of Science, First Series, vol. v. p. 52. 

 Third Series. Vol. 1. No. 4.. Oct. 1832. 2 K 



