Tar, a thick, black, unctuous matter, extracted from old pine and fir trees, by their combustion in a close, smothering heat; (see vol. iii. p. 384). It may also be procured from pit-coal; and for such purpose, Lord Dundonald obtained a patent, of which we have given a concise account in vol. ii. pp. 17, and 18.
Tar is an article of great utility, both in manufactures, and for various economical purposes : it likewise affords security to trees, from the ravages of hares, and other predatory animals : thus, if one part of tar be mixed with six or seven parts of grease, and the composition be laid on the bark with a brush, it will effectually defend plantations, and at the same time prevent the trees from being bark-bound; a disease that often occurs, from the injudicious use of tar and lime. There are, however, some delicate shrubs, to which this mixture cannot be safely or conveniently applied : hence, it will be advisable to surround them with twine covered with tar; and, as this fluid is apt to lose its odour, on exposure to the air, it must be occasionally renewed.
Though considerable quantities of tar are prepared in Britain, yet, as they are insufficient to supply the market, a great number of barrels is annually imported from Sweden, Russia, America, and other countries ; in consequence of which, it is subjected to certain duties, amounting from 12s. 1 1/2. to 14s. 4 1/2d. per last, accordingly as it is shipped in British, or foreign vessels.
Tar was formerly in great repute as a medicine, both in its original state, and also in infusions with water. It has been greatly recommended by Bishop Berkley, in the Murrain of cattle; and likewise in cold and phlegmatic habits of mankind; as it not only raises the pulse, and accelerates the circulation, but at the same time exhilarates the animal spirits. At present, however, tar-water is seldom employed; though it doubtless may, in some cases, be used with advantage ; and especially in external applications for stings. - Thus, if a person stu»g by wasp3, bees, etc. apply to the injured part a pledget dipped in such liquid, it will instantaneously mitigate acute pain, while it prevents swelling and other consequences.