138 LETTERS ON NATURAL MAGIC. 



flock : bishops and pontiffs themselves wielded the magi- 

 cian's wand over the diadems of kings and emperors, and, 

 by the pretended exhibition of supernatural power, made 

 the mightiest potentates of Europe tremble upon their 

 thrones. It was the light of science alone which dispelled 

 this moral and intellectual darkness, and it is entirely in 

 consequence of its wide diffusion that we live in times 

 when sovereigns seek to reign only through the affections 

 of their people, and when the minister of religion asks no 

 other reverence but that which is inspired by the sanctity 

 of his office and the purity of his character. 



It was fortunate for the human race that the scanty 

 knowledge of former ages afforded so few elements of 

 deception. What a tremendous engine would have been 

 worked against our species by the varied and powerful 

 machinery of modern science! Man would still have 

 worn the shackles which it forged, and his noble spirit 

 would still have groaned beneath its fatal pressure. 



There can be little doubt that the most common, as 

 well as the most successful, impositions of the ancients 

 were of an optical nature, and were practised by means of 

 plane and concave mirrors. It has been clearly shown by 

 various writers that the ancients made use of mirrors of 

 steel, silver, and a composition of copper and tin, like 

 those now used for reflecting specula. It is also very 

 probable from a passage in Pliny, that glass mirrors were 

 made at Sidon ; but it is evident that, unless the object 

 presented to them was illuminated in a very high degree, 

 the images which they formed must have been very faint 

 and unsatisfactory. The silver mirrors, therefore, which 

 were universally used, and which are superior to those 

 made of any other metal, are likely to have been most 

 generally employed by the ancient magicians. They 

 were made to give multiplied and inverted images of 

 objects, that is, they were plane, polygonal or many- 



