Chem. [f. TRI- 5 a + HYDRATE.] A compound containing three molecules of water combined with an element or radical or with another compound; also, a compound containing three hydroxyl groups, OH, united to an element or radical; e.g., bismuth trihydrate, which may be regarded as Bi2O3, 3H2O or as Bi(OH)3. So Trihydrated a., combined with three molecules of water.
1854. Scoffern, in Orr’s Circ. Sc., Chem., 374. A crystallized trihydrate of phosphoric acid results.
1868. Watts, Dict. Chem., IV. 83. Nitrates … Copper also forms a trihydrated salt, Cu″N2O6.3 H2O. Ibid. (1873), Fownes’ Chem. (ed. 11), 391. The trihydrate is the ordinary gelatinous precipitate obtained by treating solutions of aluminium salts.
1888. Muir & Morley, Watts’ Dict. Chem., I. 145. Aluminium … Trihydrate…. Occurs native, in hexagonal fibrous crystals, as gibbsite, and hydrargyllite.
