342 LETTEES ON NATURAL MAGIC. 



fluids, and to the creation of brilliant colours by 

 the combination of bodies in which no colouring 

 matter is visible. Facts of this kind are too 

 common and too generally known to require to 

 be noticed in a work like this. The art of pro- 

 ducing such changes was known to some of the 

 early impostors, who endeavoured to obtain a 

 miraculous sanction to their particular dogmas. 

 Marcos, the head of one of the sects that wished 

 to engraft paganism upon Christianity, is said to 

 have filled three transparent glasses with white 

 wine, and while he prayed, the wine in one of 

 the glasses became red like blood, that in another 

 became purple, and that in the third sky-blue. 

 Such transformations present no difficulty to the 

 chemist. There are several fluids, such as some 

 of the coloured juices of plants, which change 

 their colour rapidly and without any additional 

 ingredient : and in other cases, there would be 

 no difficulty in making additions to fluids which 

 should produce a change of colour at any required 

 instant. 



A very remarkable experiment of an analogous 

 nature has been publicly exhibited in modern 

 times. Professor Beyruss, who lived at the 

 court of the Duke of Brunswick, one day pro- 

 nounced to his highness that the dress which he 

 wore should during dinner became red ; and the 

 change actually took place, to the astonishment 

 of the prince and the rest of his guests. M. 

 Vogel, who has recorded this curious fact, has 

 not divulged the secret of the German chemist ; 

 but he observes, that if we pour lime-water into 

 the juice of beet-root, we shall obtain a colourless 

 liquid ; and that a piece of white cloth dipped in 

 this liquid and dried rapidly, will in a few hours 



