The cork bark is plunged into a cauldron of boiling water, and is left in it for half an hour. Then it is cut into strips, next into squares. It is again boiled for a quarter of an hour, and then allowed slowly to dry, and is not touched again for six months, after which it is cut into shape. The best corks are made out of strips that have been kept for three years. To whiten the corks they are subjected to sulphur fumes. The great enemy to the cork tree is the _Coroebus bifascatus_, an insect that bores a gallery, not in the bark, but in the wood of the tree. It attacks the branches, and its presence can be detected by the sickly look of the leaves. When this indication shows that it is burrowing, the branches affected are cut off above the point to which it has bored, and are burnt. At one time it was supposed that the cork tree required no culture. But of late years great pains have been taken with it, and it readily responds to them. A self-sown tree growing up in the midst of heather and cistus is not likely to attain to a great size. It is cut down to the root; then, when it sends up fresh shoots, one is kept, the rest removed. This operation has to be repeated, and the ground about the root to be well dressed. After six years the tree will take care of itself. The great danger, above all, to which the cork woods are exposed, is fire; whole tracts have been devastated in this way, and the proprietors ruined. Consequently, precautions are insisted on. Smokers are specially warned not to throw about their unextinguished matches. The carob tree (_Ceratonia siliqua_) is another that is met with, and which attracts the attention of the visitor from the north. The pods, called locust beans, are supposed to have been those on which S. John the Baptist fed when in the wilderness. These beans grow in shape like a horn, which has given its name to the tree. They contain a sweet nutritious pulp, enclosing yellow seeds. The fruit is used extensively for feeding animals, and is eaten by children, who, indeed, will eat anything. When the phylloxera was ravaging the vineyards of France, a company started a distillery at Cette to manufacture cognac out of the fruit of the carob. But it failed, as the brandy so made retained a peculiar and disagreeable flavour that could not be got out of it. The carob is an evergreen, vigorous and beautiful. It grows in most stony, arid spots, where is hardly a particle of soil. Such a tree cannot live only on what it derives from its roots; it must live in a great measure by its leaves, as, indeed, to a large extent, do all evergreens. The scanty soil will in many places not feed trees that drop their leaves in autumn, and supply them afresh every spring. Such renewal exacts from the poor soil more than it can furnish. Consequently, Nature spreads evergreens over the rocky surfaces that contain but slight nutritive elements. Thus it is that in Provence the vegetation is nearly all of an evergreen character.