Its elementary constituents are,
| Carbon | 6·812 | 8 proportions. |
| Hydrogen | 1·000 | 7 ditto. |
This new material (when mixed with alcohol) is a solvent of all the resins and particularly of copal, which it dissolves, without artificial heat, at the ordinary temperature of the atmosphere; a property possessed by no other solvent known; and hence it is peculiarly useful for making varnishes in general. It also mixes readily with oils, and will be found to be a valuable and cheap menstruum for liquefying oil-paints; and without in the slightest degree affecting the most delicate colours, will, from its ready evaporation, cause the paint to dry almost instantly.
Cocoa-nut oil, at the common temperature of the atmosphere, always assumes a concrete form; but a portion of this caoutchoucine mixed with it will cause the oil to become fluid, and to retain sufficient fluidity to burn in a common lamp with extraordinary brilliancy.
Caoutchoucine is extremely volatile; and yet its vapour is so exceedingly heavy, that it may be poured, without the liquor, from one vessel into another like water.
CAPERS. The caper is a small prickly shrub, cultivated in Spain, Italy, and the southern provinces of France. The flowers are large roses of a pretty appearance, but the flower buds alone are the objects of this cultivation.
They are plucked before they open, and thrown into strong vinegar slightly salted, where they are pickled. The crop of each day is added to the same vinegar tub, so that in the course of the six months during which the caper shrub flowers, the vessel gets filled, and is sold to persons who sort the capers, (the smallest being most valued) by means of copper sieves. This metal is attacked by the acid, wherefrom the fruit acquires a green colour, much admired by ignorant connoisseurs.
The capers, as found in the French market, are distinguished into five sorts; the non-pareille, the capucine, the capote, the second, and the third; this being the decreasing order of their quality, which depends upon the strength of the vinegar used in pickling them, as also the size and colour of the buds.
The caper shrub grows in the driest situations, even upon walls, and does not disdain any soil; but it loves a hot and sheltered exposure. It is multiplied by grafts made in autumn, as also by slips of the roots taken off in spring.