1726 ARBORETUM AND FRUTICETUM. PART III. 



The bark of Q. Suber furnishes suberine, the suberic acid, and a product 

 by far more important than that of any species of the genus, cork ; a substance 

 which is not produced by any other tree whatever, in sufficient quantities to 

 be applied to any useful purpose. 



The leaves, the flowers, and the fruit, according to Bosc, afford nourish- 

 ment to more than 200 species of insects, even in the neighbourhood of Paris; 

 and some of these insects are either valuable themselves in the arts, or they 

 are the cause of excrescences, such as oak galls, which are valuable. The 

 leaves of Q. coccifera afford nourishment to the Coccus ilicis, a hemipterous 

 insect, which is used in medicine under the name of kermes, and has been 

 employed in dyeing scarlet, from the remotest antiquity, under the name of 

 scarlet grain. This insect is produced, and cultivated for commerce, in the 

 south of France, and in various parts of the south of Europe, and of the East. 

 Oak galls, which are much in demand for the manufacture of ink and for dyeing 

 black, are produced on most of the deciduous European species, and are very 

 abundant on the section 7?6bur ; but the galls of commerce are chiefly pro- 

 duced by the Q. infectoria, a native of Asia Minor and the adjoining countries. 

 All the smaller parts of oaks, such as the spray, buds, leaves, flowers, and 

 fruit, may be employed in tanning ; and, accordingly, the cups, or calyxes, of 

 some species are in use for this purpose, more particularly those of the valonia 

 oak (Q. ./22'gilops), a native of the Archipelago. The leaves of the section 

 .ffobur are used as a substitute for spent tanner's bark in hot-houses ; and 

 being slow in decomposition, are found to retain the heat for a longer period 

 than those of any other European trees. 



The acorns of all the species are edible ; and, in every country where the 

 oak abounds, they form the most important part of the food of wild quadru- 

 peds of the fructivorous or omnivorous kinds, and of some birds. The wild 

 animals most useful to man, which are nourished by them, both in Europe 

 and America, are the wild boar, the stag, and the goat. In Asia, pheasants 

 and pigeons, with other birds in a wild state, eat acorns, no less than wild qua- 

 drupeds. In North America, cows, horses, swine, bears, squirrels, pigeons, 

 and wild turkeys devour them. Among the domestic animals which eat and 

 thrive on acorns, the principal is the swine ; but there are few animals and 

 birds, in a state of domestication, Bosc observes, that may not be made to 

 live and thrive on them, however unwilling they may be to touch them at 

 first. In the earlier ages, there can be no doubt that acorns, in the countries 

 where thev were produced, were the food of man ; and the}' are still, as we 

 have seen, eaten in some parts of the south of Europe, the north of Africa, 

 and the west of Asia. The kinds which produce the acorns most valued 

 for eating are, Q. /'lex, Q. Ballota, Q. gramuntia, and Q. .E'sculus. The degree 

 of bitterness in acorns, produced by tli" same species, varies exceedingly on 

 different trees ; and were any kind of oak to be introduced into orchards as a 

 fruit tree, it would be advisable to select only the best varieties of particular 

 species, and propagate these by grafting. There are even varieties of Q. 

 Robur which produce acorns much less bitter than others; and we have 

 received some from a tree of this species, in the south of France, which ac- 

 cording to Dralet, are so sweet as to be eaten by the inhabitants. (See Re- 

 cherches sur les Chenes a Glands doux, p. 178.) 



The entire tree or shrub, in the case of every species of oak, may be con- 

 sidered as highly ornamental : the least so are the willow-leaved oaks, and 

 the most so the lobed and deeply sinuated leaved kinds. The foliage, even, 

 of the same species, and more especially of the deciduous kinds, varies ex- 

 ceedingly ; not onlv on different individuals, but on the same individual at 

 different seasons of the year. In spring, the leaves of many of the decidu- 

 ous kinds are small, delicate, and beautifully tinged with yellow and red ; in 

 summer, they are broad and green; and in autumn, coriaceous, and of a 

 russet brown, scarlet, or blood-red colour. Nothing can be more remarkable 

 than the variation in the forms of the leaves, in the same individual, in some 

 of the American species ; those of the tree, when young, being sometimes 



