58 THE CHEMISTRY OF CREATION. 



found that all these effects of the solar ray 

 pass off, and all bodies restore themselves again 

 to their original condition. It is not, therefore, 

 to man and the animate world in general, and 

 to vegetation, alone, that night and gentle 

 sleep conie " as Nature's sweet restorers ;" the 

 great earth must rest likewise. These fields and 

 yonder, hills sleep, and become restored and 

 refreshed equally with the. living and moving 

 beings on their surface. Night is precious 

 alike to all ; in truth, it is indispensable. 



The beautiful contrivance now so largely 

 employed for the purpose of portrait taking, 

 the Daguerreotype, exhibits in a singularly 

 striking manner to us the potency and rapidity 

 of action of the actinic rays of the sunbeam. 

 In a darkened chamber, generally in a little 

 box appropriately fitted, the rays of light pro- 

 ceeding from the sitter's figure are collected 

 by means of a lens, and are caused to fall upon 

 a silvered plate, which has been prepared by 

 exposing it to the vapour of iodine and bro- 

 mine. In a second of time the most faithful 

 picture of the person is fixed upon the metal 

 surface, in lines which years cannot efface. By 

 means of a camera obscura, and paper pre- 

 pared in a peculiar manner, Mr. Fox Talbot 

 has succeeded in producing the most exquisite 

 sun-pictures, in which all the varying tones of 



