ITTRIA. This earth was discovered by Gadolin, a Swedish chemist, in a fossil, found at Ytterby, in Sweden, which has since received the name of gadolinite, and in which it is combined with silex and lime. The discovery was confirmed by Ekeberg, Klaproth, and Vauquefin ; and the same earth has been discovered in some other fossils, particularly com bined with lantalium. In several of its properties ittria resembles glucine, par ticularly in forming salts of a sweet taste, and in being soluble in carbonate of am monia ; but it differs entirely in others, The process followed by Vauquelin to obtain this earth from the gadolinite was, to dissolve it, with the assistance of heat, in diluted nitric acid, pouring off the solu tion from the undissolved silex. The liquor is then evaporated to dryness, by which any remaining silex and any oxide of iron is separated from combination with the acid. By redissolving the resi duum in water, the compound of nitric acid and ittria is obtained: if there are any traces of iron, the liquor is either again evaporated to dryness, or a little ammonia is added ; and after the separa tion of the oxide of iron by yellow flakes, the solution is decomposed by ammonia, which precipitates the new earth. (Philo sophical Magazine, vol. viii. p. 369.) The process employed by Klaproth is similar, nitro-muriatic acid being employed ; the iron being removed by the action of suc cinate of soda ; and the ittria being pre cipitated by carbonate of soda. (Analyti cal Essays, vol. ii. p. 47.) Ittria is obtained in the form of a white powder, and is heaver than any other earth ; its specific gravity according to Ekeberg being 4.842. It is not fusible alone, but with borax it forms a white glass. It is not soluble in water, but it retains that fluid with considerable force.
Ittria combines with the acids; its salts, as has beeu remarked, having generally a sweetish taste. Several of them, too, are coloured, a property iu which it differs from all the other earths.
The sulphate of ittria crystallizes in small brilliant grains, according to Klap roth, of a rhomboidal form, and of a colour inclining to an amethyst red. Their taste is sweet, becoming also astringent. require from twenty-five to thirty parts of water, and are not more soluble in hot water. Their specific gravity is 2.79. The sulphuric acid is expelled by a red heat. Nitrate of ittria can scarcely be crystallized ; it assumes a gelatinous con sistence by evaporation, and becomes brittle when this jelly cools. Its taste is similar to that of the sulphate. The mu
riate is obtained nearly in the same form. The phosphate, formed by complex affi nity, is insoluble. The acetite is a crys tallizable salt of a pale red colour.
The salts of ittria are decomposed by the three alkalies, and by lime, astronti tes, and barytes.
Ittria is not dissolved by the liquid alka lies, nor do they redissolve it when added in excess, after having precipitated it from its solutions. This affords a distinguish ing character between it and glucine.
It is soluble in the alkaline carbonates, particularly in the carbonate of ammonia.
Prussiate of potash throws down from its solution a granular precipitate, of a white or pearl-grey colour. It is also pre cipitated in grey flocculi by the watery or spirituous infusion of galls ; but very slightly by the pure gallic acid. It is not affected by sulphuretted hydrogen, or hydro-sulphuret of ammonia, added to its solutions.
The great specific gravity of this earth, its forming coloured salts, and being pre cipitated by the alkaline prussiates, and by tannin, from its solutions, in some measure connect it with the metals, and lead to the suspicion that it may be a me tallic oxide.
The gadolinite is the only fossil that can be considered as belonging to the ge nus of which this earth is the base, for the yttrotantalite contains it in small quantity only, and is properly a metallic fossil be longing to the genus Tantalium. The gadolinite occurs massive, and dissemi its colour is a deep greenish black. Its internal lustre is resplendent ; it is opaque ; its fracture is conchoidal ; its hardness is such, that it is not scratched by the knife ; its specific gravity is 4.2. It intumesces before the blow-pipe, but is not fused. With nitric acid it forms a gelatinous solution. According to Klap roth, it consists of ittria 59.75, silex 21.25, oxide of iron 17.5, argil 0.5, water 0.5. The analysis of it by Ekeberg and Vau quelin, give the proportion of ittria rather less, and of silex and iron somewhat more.
IVA, in botany, a genus of the Monoe cia Pentandria class and order. Natural order of Compositm Nucamentacew. Co rymbiferm, Jussieu. Essential character: male, calyx common, three-leaved ; co rolla of the disk, one-petalled, five-cleft ; receptacle with hairs or linear chaffs : fe male, in the ray, five, or fewer ; corolla none ; styles two, long; seeds naked,, blunt. There are two species, viz. 1. an nua, annual iva, and I. frutescens, shrubby iva, or bastard Jesuits' bark tree.