Oak is tough, durable, easily obtained, liable to warp and check in seasoning, often hard to nail without splitting, susceptible of high polish, and not greatly liable to attack by insects. It contains gallic acid, causing peculiar taste and odor and attacking iron, the solutions staining the wood. Experiments[13] indicate that iron fastenings are shortly protected by an insoluble scale of resulting salt, and that the wood, although [p012] darkened, remains practically uninjured. The later oaken vessels were iron-fastened,[14] and cabinet-makers now employ that metal in joining oak. The barks of all species are also so charged with acid as to be used in the tanning of leather. The several kinds of oak are commercially divisible into three general groups, white oak, red or black oak, and live oak.[15] The principal species affording woods under each head are as follows:

Live Oak
(Quercus virginiana).

Oak trees are characterized by oblong, thin-shelled kernels, protruding from hard scaly cups and called acorns. The foliage is sometimes deciduous and sometimes evergreen. Most oaks require many years to reach maturity, but are then long-lived. Fifty of the nearly three hundred known species of oak are natives of the United States and Canada; all but four become trees under favorable conditions. Quercus is from two Celtic words, quer, signifying fine, and cuex, a tree. [p013]

FOOTNOTES

[12] Thought by some botanists to be distinct species, namely, Quercus pedunculata and Quercus sessiliflora.

[13] Havemeyer Chemical Laboratory, N. Y. University.

[14] Communication. Mr. Chas. H. Cramp, President Cramp Ship-building Co., Philadelphia.

[15] This division is also a botanical one based not only on differences in anatomical structure of the wood itself, but on the time required by fruit in attaining maturity, and on persistence of foliage (evergreen or deciduous), etc.