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ANNUAL OP SCIENTIFIC DISCOVERY. 



which destroys the other kinds of black, while it changes chrome- 

 black to a chesnut-brown. 



The examination of mixed colors is somewhat more complicated ; 

 but as they are for the most part constituted of the substances already 

 mentioned, it will not be difficult, by means of the above reactions, to 

 ascertain in what manner and with what materials such colors have 

 been produced. Beiblatt zur DeutzcJie Muster zeilung. 



