MAGIC MIRRORS. 191 



colour, chemical composition, mechanical structure, calo- 

 rific condition, or electrical state,) has a power of radia- 

 tion by which a sensible change can be produced in a 

 body differently constituted. 



Fable has told us that the magicians of the East pos- 

 sessed mirrors in which they could at will produce 

 images of the absent. Science now shows us that repre- 

 sentations quite sufficient to deceive the credulous can 

 be produced on the surface of polished metals without 

 difficulty. A highly polished plate of steel may be im- 

 pressed with images of any kind, which would remain' 

 invisible, the polished surface not being in the least degree- 

 affected, as it regards its reflecting powers ; but by breath- 

 ing over it, the dormant images would develope them- 

 selves, and fade away again as the condensed moisture 

 evaporated from the surface.* 



These, which are but a few selected from a series of 

 results of an equally striking character,, serve to con- 

 vince us that nature is unceasingly at work, that every 

 atom is possessed of properties by which it influences 

 every other atom in the universe, and that a most im- 

 portant class of natural phenomena appear to connect 

 themselves directly with the radiant forces. 



The alchemists observed that a change took place iu 

 chloride of silver exposed to sunshine. Wedgwood first 

 took advantage of that discovery to copy pictures. 

 Niepce pursued a physical investigation of the curious 

 change, and found that all bodies were influenced by 

 this principle radiated from the sun. Daguerre produced 

 effects from the solar pencil which no artist could ap- 

 proach to ; and Talbot and others extended the applica- 



* Cornelius Agrippa is said to have possessed such a mirror. 

 The Chinese make mirrors which, when placed in a particular 

 light, show upon their polished faces the pattern on the back of the- 

 metal, although it is invisible in every other position. This is 

 effected by giving different degrees of hardness to the various 

 parts of the metal. In Natural Mayic, by Sir David firewater, 

 several curious experiments belonging to this class are named. 



