“I ought, perhaps, to add that theine collected as a waste product of coffee, and purified by myself, has cost me less than threepence per ounce troy.”
THENARD’S BLUE. See Ultramarine (Cobaltic).
THEOBROMÆ OLEUM. Syn. Cacao butter. A concrete oil, obtained by expression and heat from the ground seeds of Theobroma Cacao. Occurs in cakes of a yellowish colour, of a pleasant cacao odour. Does not become rancid from exposure to air. Contained in all the suppositories.
Not official.—The following form good bases for suppositories:—Theobroma oil, when melted, begins to solidify at 72° Fahr.; stearine of cocoa-nut oil at 75° Fahr.; 4 of stearine and 2 of mutton fat at 77° Fahr.; 4 of stearine and 1 spermaceti at 80° Fahr. Stearine alone is, perhaps, a better substance than cacao butter for making suppositories. It begins to solidify at 78° Fahr., but there is stearine that solidifies at 120° Fahr.; this will not answer for suppositories.
THEOBRO′MINE. A peculiar principle, closely resembling caffeine or theine, found by Woskresensky in the seed of the Theobroma Cacao, or the nuts from which chocolate is prepared. Its form is that of a light, white, crystalline powder, which is rather less soluble than caffeine. It is obtained like caffeine. See Cocoa.
THERI′ACA. A name given in ancient pharmacy to various compound medicines, chiefly electuaries or confections, employed as antidotes to poisons or infection. The Theriaca Andromachi, Ph. L. 1746, contained above 60 ingredients. Mithridate and Venice treacle are examples of this class. See Treacle.
THERMOM′ETERS. Fahrenheit’s scale is the one generally employed in England, while that of Celsius, or the Centigrade scale, is principally used on the Continent. Reaumur’s is another scale occasionally employed. De Lisle’s thermometer was formerly used in Russia, and some other parts of the north of Europe. As references to these scales are frequently met with in books, it is useful to know their relative value, and the method of reducing the one to the other. The boiling point of water is indicated by 212° on Fahrenheit’s scale, 100° on the Centigrade scale, 80° on that of Reaumur, and O° on that of De Lisle; the freezing point of water marks 32° Fahrenheit, and 0°, or zero, on the Centigrade and Reaumur, and 150° on the scale
of De Lisle. The 0°, or zero of Fahrenheit, is 32° below the freezing point of water.
1. To reduce Centigrade degrees to those of Fahrenheit, multiply them by 9, divide the product by 5, and to the quotient add 32; that is—
Cent.° × 9 / 5 + 32 = Fahr.°