[ 20 ] 
COPPER. 
GREEN is the only colour which chopper,, 
the metal next to lilver in denjity^ communicates to 
ghjsy when melted with it in a fufficient heat, 
'Without any additional ingredient: Thus 
1. By grinding cryjial glafs in a copper mortar, and 
afterwards melting it, it becomes green.. 
2. Copper calcined per in a furnace [y.]. 
3,. Copper calcined with fulphur [r], and 
4. Scales beaten off from red hot copper plates 
mixed with glafs, equally impart a green colour. 
to it. 
It is indifferent in what manner the copper is 
prepared, in order to tinge the glafs green, pro- 
vided it be expofed, 'without any other ingredient, tp 
a fufficient degree of heat [s]. 1 have frequently pro- 
duced a fine green from copper filings unprepared. 
^ {q'] Shaw’s Abridg. Boyle, vol.ii'. p. gS’. Though copper 
dried per fe affords but a dark and bafely-coloured calx, yet the 
glafs-men tinge their glafs green therewith. 
Neri, chap. 92. This fort of pnreji glafs will be tinged into 
all colours you define : for example, into an emerald with brafs 
thrice calcined,, as is done foe ordinary glafs : into a fea greerh 
with brafs calcined to rednefs. 
[/■] Junker, Confp. Cbem. tab. xix. p. 433. Beryllus ma- 
rinae viriditaUs per cuprum cum fulphure calcinatum., 
[s] Kunkel’s Notes on Neri, chap..32. Though with copper 
alone one may produce green,^ it is neverthelefs crocus martis dif- 
ferently prepared that makes a variety in it.. I-^have- not foui>d 
that the different manners of preparing copper have producad 
different colours, f have experienced that by calcining copper per 
fe, without any addition, I could produce all the elfeds that the 
author t.eaches us to bring about by different preparations of that 
metaU 
lx 
