PHYSICAL AND LITER'ARY. ^J 



feems to have nothing of rednefs in it : 

 green is transformed into another fort of 

 brown, only diftinguifhable from the former 

 hy ar certain inclination to a livid olive-co- 

 lOur; when nitre is mixed with the fpirits," 

 one may ftill fee fome remains of a greenifh 

 colour, unlefs it be poured in very "plenti- 

 fully -..dark- blue is hardly to be known 

 from black, except that it appears th^ deeper- 

 black 6i the two?: ' Jigiit blue' is changed 

 into d very light brown of a peculiar kind : 

 white aifumes a livid yellowifh caft : and 

 yellow alone appears unaltered arid ex- 

 tremely luminous. Thefe experiments I 

 made with different forts of rich^coloured 

 bodies, as filks, cloths and paintSi Poliflied 

 copper, which has contrafted from the air a 

 high-flaming colour, is reduced by the fame 

 light into the appearance of yellow brafs j 

 the faces and hands of fpeftators appear 

 like thofe of a dead corpfe j and other rnixed 

 colours,' which have red or green in their 

 compofition, undergo like changes. 



27. Having placed a pafte-board with a 



circular hole in it between my eye and the 



•flame of the fpirits, in order to diminifh 



and circumfcribe my object, I examined the 



Vol. IL E conftitution 



