African copals are the hardest, they much resembling amber. They are easily distinguished from it, however, as they will readily melt if brought into contact with the flame of a candle.
There are many kinds, the following being the best known:—Zanzibar, Madagascar, Cape of Good Hope, Sierra Leone, Congo, and Angora. The solubility of copals has been mentioned before when describing the rosins. They are a mixture of various matters of similar constitution, but which differ in several essential points, notably by the variations in the degree of solubility.
Certain other bodies mixed with the rosin will greatly facilitate their dissolution in alcohol, camphor and ammonia being generally used for this purpose. The process is very gradual, but camphor is extensively employed by most makers.
Anime.—This copal is the produce of America, Brazil and Cayenne. It is very hard, but readily dissolves in alcohol.
Dammar.—This comes from Australia and New Zealand, is partly soluble in alcohol but not completely so by the cold process.
