BY THE SOLAR RAYS. 167 



aiid it breaks up some of the strongest forces of chemi- 

 cal affinity. To modern science is entirely due the 

 knowledge we have gained of the marvellous powers of 

 the sunbeam ; and it has rendered us familiar with 

 phenomena, to which the incantation scenes of the 

 Cornelius Agrippas of the dark ages were but ill-con- 

 trived delusions, and their magic mirrors poor instru- 

 ments. The silver tablets of the photographic artist 

 receiving fixed impressions of the objects represented in 

 the dark chamber by a lens, are far superior as ex- 

 amples of natural magic. 



In the dark ages, or rather as the earliest gleams of 

 the bright morning of inductive research were dis- 

 pelling the mists of that phantom-peopled period, it was 

 observed, for the first time, that the sun's rays turned a 

 white compound black. Man must have witnessed, long 

 before, that change which is constantly taking place in 

 all vegetable colours : some darkening by exposure to 

 sunlight, while others were bleached by its influence. 

 Yet those phenomena excited no attention, and the 

 world knew nothing of the mighty changes which were 

 constantly taking place around them. The alchemists 

 sublime pictures of credulous humanity toiling in 

 the smoke of their secret laboratories, waiting and 

 watching for every change which could be produced by 

 fire, or by their ' ( royal waters," caught the first faint 

 ray of an opening truth ; and their wild fancy, that 

 light could change silver into gold, if they but succeeded 

 in getting its subtile beams to interpenetrate the metal, 

 was the clue afforded to the empirical philosopher to 

 guide him through a more than Cretan labyrinth.* 



* See Researches on Light, by the Author. Reference to any of 

 the works of the alchemists will prove the prevalence of the idea 

 expressed in the text. We find that gold was considered to be 

 always under the influence of light and solar heat. " It is said of 

 gold that it waxeth cold towards daylight, insomuch that they who 

 wear rings of it may perceive when the day is ready to dawn." 



