Microscopic appearance of tapioca.
Pure tapioca is insipid, inodorous, only slightly soluble in cold water, but entirely soluble in boiling water, forming a translucent and highly nutritious jelly. Its granules are muller-shaped, about 1⁄2000 of an inch in diameter, and display very marked hilums. It
is used in a similar manner to sago and arrow-root. See Cassava.
TAPS, WOODEN (to prevent their cracking). The taps are placed in mother paraffin, heated to from 110° to 120°; by this means the water is eliminated from the wood, and the wood becomes thoroughly impregnated with paraffin. The taps are heated in this bath until all the aqueous vapour has been expelled, and are left in it, after the removal of the vessel from the fire, up to the very moment the paraffin begins to solidify. Wooden taps thus prepared are very durable, do not become soaked with liquids, keep very tight, and are not liable to become mouldy. The excess of paraffin is wiped off with care, and the taps are next rubbed clean with a piece of flannel. (Dr E. Kopp.)[224]
[224] ‘Chemical News.’
TAR. Syn. Pix liquida (B. P., Ph. L., E., & D.), L. A liquid bitumen prepared from the wood of Pinus sylvestris, and other species, by heat. The chemical constitution of tar is very complicated. Its uses in the arts are well known. As a medicine it is stimulant, diuretic, sudorific, and vermifuge.—Dose, 20 to 60 minims, made into pills with flour; in ichthyosis, &c. Externally, in lepra, psoriasis, foul ulcers, &c. See Ointment and Infusion.
Tar, Barbadoes. Syn. Pix liquida Barbadensis, Petroleum Barbadense, Petroleum (Ph. L. and E.), L. “Black liquid bitumen, exuding spontaneously from the earth.” (Ph. L.) Its properties for the most part resemble those of the last.—Dose, 10 to 30 drops; in asthma, chronic coughs, tapeworm, &c. Externally, in chilblains, chronic and rheumatic pains, &c. See Petroleum.
Tar, Coal. Produced during the distillation of bituminous coal for gas. See Naphtha, &c.
TARAX′ACUM. See Dandelion.