54 Major-General Straton's Description of the 



measuring light, little, if at all, inferior to that of shadows- 

 When an opaque body was interposed between one of the 

 candles and the eye, the images which appeared white before, 

 changed immediately to green and red ; and if both eyes were 

 then shaded from the light by means of opaque bodies, the 

 images resumed their white colour 



• In making these last experiments, another new and inte- 

 resting appearance presented itself to my observation. My 

 two eyes being shaded from the direct light of the candles, 

 when I removed both of the opaque bodies suddenly, and 

 thus admitted the direct light of the candles into my eyes, I 

 was surprised to find that the two images of the slip of white 

 paper appeared immediately and distinctly more luminous. 

 This phenomenon, in all the trials I have made, lasts only for 

 a few seconds, the sensation being similar to that which would 

 be produced by the paper being more illuminated by a sud- 

 den flash of light. 



Satisfied with barely announcing to the Society these new 

 and curious phenomena, I forbear to offer any attempt at an 

 explanation of them. All I shall at present say, is, that they 

 appear to me to be produced by an important function of the 

 eye, which has entirely escaped the notice of the writers on 

 Vision. I have the honour to be, Sir, 



Your most obedient Servant, 



Kingussie, 28th March 1826. T. Smith. 



Art. XI Description of the Great Temple of Carnac, in 



Thebes. By Major-General Straton, F. R. S. Edin. 

 With a Plate. Communicated by the Author. 



The first impressions conveyed by the great Egyptian temples 

 are those of sublimity and colossal solidity. The beholder, on 

 coming nearer to them, is delighted with the symmetry and 

 just proportions of the constituent parts. On a close ap- 

 proach, while he is gratified with the accuracy and perfection 

 of the details, he is astonished at the degree of perfection 

 which the arts of statuary, sculpture, and design, had attained 



