Oil of Camphor.
7 Oil of Camphor.—This liquid is frequently used for the purpose of moistening the compositions; it is thus easily procured: put a small quantity of Camphor into a brass mortar, and to it add some oil of sweet almonds, sufficient to reduce it to a stiff paste, then work the mixture well together, and it will turn to a green colour, after which add a sufficient quantity of oil to liquify it for use. We must observe on the use of this liquid, that the composition into which it enters must be kept as much as possible from the air, as an exposure to it will cause it to evaporate, and thereby cause a failure in the exhibition.