Brass* 
95 
of them approaching nearer to the qualities of gold, ex- 
cept in weight, than any other yet discovered* It takes a 
most beautiful polish, is less liable to tarnish or to be 
scratched than gold, and though very ductile, it is capa- 
ble of being rendered extremely strong and elastic : It is 
peculiarly adapted for watch cases, snuff boxes, and all the 
variety of trinkets for which gold is at present employed : 
the inventor supplies the unwrought metal at a very rea- 
sonable rate.— 4 Com . Mag. 362. 
A summary of these alloys of copper and zinc, and 
copper and tin, is given by Aiken as follows : 
Copper with Zinc . Copper nearly saturated with zinc, 
that is, in which the latter makes about a fourth (more or 
less) of the mixture, forms brass , the most important of 
all the alloys of this metal, and which has been fully de- 
scribed under that article. With a much less propor- 
tion of zinc the colour of the alloy approaches very nearly 
to that of gold, and the malleability increases. Mixtures 
chiefly of these two metals are used to form a variety of 
yellow or gold-coloured alloys, known by the names of 
Tombac , Manheim or Dutch Gold, Timely Similar , Prince 
Rupert's Metals Pinchbeck , 8tc. but the precise compo- 
sition varies according to the fancy or the experience of 
different manufacturers. The Dutch gold may be beat- 
en out into extremely fine leaves, which, when fresh, have 
nearly the brilliance of gold-leaf, and are used as a cheap 
imitation of it, but they tarnish very soon. The mixture 
may be made either by directly melting copper and zinc* 
or by mixing brass and copper. In either case the cop- 
per should be melted first, and the zinc added afterwards, 
! the whole stirred together with wood, covering it with a 
1 little charcoal, and poured out immediately, to prevent 
the loss by the burning off of the zinc. 
Several direct experiments on the union of copper and 
zinc in different proportions were made by Marggraf* 
