GOLD. 167 
galvanic electricity, or a flame produced by the agency 
of oxygen gas. 
It is admirably adapted for the uses of the philoso- 
phical chemist: although vessels made of it must al- 
ways be found expensive, from its being necessary to 
solder them with gold; and although it has the disad- 
vantage of being subject to corrosion by the application 
or use of caustic alkalies. Vessels made of it are not 
liable to be broken, and are as indestructible as those 
made of gold. When properly refined, its colour is 
somewhat betwixt that of silver and iron. Not being 
liable to tarnish like silver, platina is manufactured into 
several kinds of trinkets. 
Its ductility is so great that it may be rolled into 
plates, or drawn into wire ; and platina wire, for strength 
and tenacity, is considered much preferable to that 
either of gold or silver of equal thickness. Platina is 
also made into mirrors for reflecting telescopes, into 
mathematical instruments, pendulums, and clock- 
work ; particularly where it is requisite that the con- 
struction of these should be more than usually correct, 
as platina is not only free from liability to rust, but is 
likewise subject to very little dilatation by heat. It is 
sometimes beaten into leaves and applied to porcelain, 
in the same manner as leaf gold ; and its oxide (21) is 
vised in enamel painting, and might be used, with great 
advantage, in the painting and ornamenting of porcelain. 
The platina employed for all thesepurposes is repeatedly 
melted with arsenic, as without the aid of this it could 
only be obtained in very small masses, owing to the in- 
tense heat that is required for its fusion. 
This extraordinary metal was unknown in Europe 
until about the year 1735, when it was first brought 
from South America by Don Antonio Ulloa. 
227. GOLD is a metal distinguished by its yellow colour 
by its being next in weight to platina, softer than silver, fat 
considerably more hard than tin ; and being more easily melted 
than copper. 
It is found in various states, massive, in grains, small 
