24 
COPAL AND COPAL VARNISH. 
same way as on hard copal. Its fusing point is between that of 
the globular and the hard copals. When in a state of fusion, it 
gives off less acid than the former, but much more oil (volatile as 
well as empyreumatic) than the latter ; in other respects it re- 
sembles the hard copal. By careful treatment, a transparent var- 
nish is obtained with it ; but so soft and so slow in drying, that it 
would be as well altogether to reject its use in the manufacture of 
varnish. 
To Prepare a Varnish for Coating Metals. — Digest one part of 
bruised copal in two parts of absolute alcohol ; but as this varnish 
dries too quickly, it is preferable to take one part of copal, one part 
of oil of rosemary, and two to three parts of absolute alcohol. This 
gives a clear varnish, as limpid as water. It should be applied hot, 
and, when dry, it will be found very hard and durable. 
To Prepare a Varnish for the Scales of Thermometers. — I 
recommend the following : — One part of copal, one part of oil of 
rosemary, and three parts of oil of turpentine, recently rectified or 
digested with sulphur. After a moderate digestion, the varnish is 
ready for use. This varnish dries quick, but is not so hard as the 
preceding, although it resists the action of the air and atmospheric 
influences. 
For Varnishing Leather. — Especially of delicate colors, I re- 
commend the following : — Six parts of oil of turpentine, saturated 
with caoutchouc, two parts of copal, and two parts of oil of rose- 
mary. This varnish should be applied somewhat fluid, and always 
dried at a high temperature. 
For Varnishing Furniture. — The fused copal dissolved in oil of 
of turpentine is the most economical. If the copal has not been 
kept a sufficient time in a state of fusion, the varnish made with it 
remains soft for some time after it is dry, and afterwards peels off. — 
Pharm. Jour., Aug. 1, 1850. 
