leaved; petals three, converging; seed one, three-sided. There are thirty-six species.

RUMMAGE, in the sea-language, signifies to clear a ship's hold, or to remove goods from one place of it to another.

RUMOURS, spreading such as are false is criminal, and punishable by common law.

RUMPHIA, in botany, so named in honour of George Everhard Rumphius, M. D. a genus of the Triandria Monogy nia class and order. Natural order of Terebintaceæ, Jussieu. Essential character: calyx three-cleft; petals three; drupe three-celled. There is only one species, viz. R. amboinensis, a native of the East Indies.

RUNDLET, or RUNLET, a small vessel, containing an uncertain quantity of any liquor; from three to twenty gallons.

RUNGS, in a ship, the same with the floor or ground timbers, being the timbers which constitute her floor, and are bolted to the keel, whose ends are rungheads.

RUNG-heads, in a ship, are made a little bending, to direct the sweep or mould of the futtocks and naval timbers; for here the lines, which make the compass and bearing of a ship, do begin.

RUNIC, a term applied to the language and letters of the ancient Goths, Danes, and other northern nations.

RUNNER, in the sea language, a rope belonging to the garnet, and to the two bolt tackles. It is reeved in a single block, joined to the end of a pennant, and has at one end a hook to hitch into any thing, and at the other end a double block, into which is reeved the fall of the tackle, or the garnet, by which means it purchases more than the tackle would without it.

RUNNET, or RENNET, the acid juice found in the stomach of calves that have fed on nothing but milk, and are killed before the digestion is perfect.

RUPALA, in botany, a genus of the Tetrandria Monogynia class and order. Natural order of Contorte. Protæ, Jussieu. Essential character: calyx none; petals four, cohering at the base; stamina inserted into the middle of the petals; pericarpium one-celled, one-seeded.There are two species, viz. R. montana and R. sessilifolia, both natives of Cayenne.

RUPERT'S drops, a sort of glass-drops, with long and slender tails, which burst to pieces on the breaking off those tails in any part, said to have been invented VOL. X.

by Prince Rupert, and therefore called after his name. This surprising phenomenon is supposed to rise from hence, that while the glass is in fusion, or in a melted state, the particles of it are in a state of repulsion; but being dropped into cold water, it so condenses the particles in the external parts of their superficies, that they are easily reduced within the power of each other's attraction, and by that means they form a sort of hard case, which keeps confined the beforementioned particles in their repulsive state; but when this outer case is broken, by breaking off the tail of the drop, the said confined particles have then a liberty to exert their force, which they do by bursting the body of the drop, and reducing it to a very peculiar form of powder.

RUPPIA, in botany, so named in memory of Henry Bernhard Ruppius, a genus of the Tetrandria Tetragynia class and order. Natural order of Inundatæ. Naiades, Jussieu. Essential character: calyx none; corolla none; seeds four, pedicelled. There is but one species, viz. R. maritima, sea ruppia, or tassel pond-weed.

RUSCUS, in botany, butcher's broom, a genus of the Dioecia Syngenesia class and order. Natural order of Sarmentacex. Asparagi, Jussieu. Essential character: calyx six-leaved; corolla none; nectary central, ovate, perforated at the top. There are five species.

RUSSELIA, in botany, so named in honour of Alexander Russel, M. D. a genus of the Didynamia Angiospermia class and order. Natural order of Personatæ. Scrophulariæ, Jussieu. Essential character: calyx five-leaved, setaceous at the end; corolla tube very long, hairy at the throat; border two-lipped, lower lip trifid; capsule acuminate, one-celled, two-valved, many-seeded. There is only one species, viz. R. sarmentosa, found by Jacquin about Havana, in close woods and coppices.

RUST of a metal, a word that has now given way to the modern term Oxide, which see.

RUTA, in botany, rue, a genus of the Decandria Monogynia class and order. Natural order of Multisiliquæ. Rutuceæ, Jussieu. Essential character: calyx fiveparted; petals concave; receptacle surrounded by ten honey dots; capsule lobed. There are seven species.

RUTILE, in mineralogy, a species of the Menachine genus, of a dark blood-red colour, of various degrees of intensity,

Rr

passing to a brownish red. It occurs crystallized, and the crystals are longitudinally streaked; externally it is shining and glistening; internally its principal fracture is splendent. It is slightly translucent, brittle; it yields a pale yellow or orange yellow coloured streak It is easi ly frangible; specific gravity about 4.2. Without addition it is infusible before the blow-pipe; with borax or alkali it affords a hyacinth transparent glass. It is found to be a pure oxide of menachine, with a slight portion of silica.

RUTULITE, a mineral found in Norway, of a yellowish colour; it occurs massive, disseminated, and crystallized. The crystals are small, singly imbedded, and seldom aggregated. It is translucent on the edges, or opaque, yields a grey streak; it is hard, brittle, and easily frangible. Specific gravity S.5. It experiences little change before the blowpipe, without addition, but with borax it forms a yellowish-green transparent bead; the constituent parts are different, according to the place from which the specimens are found; one from Norway was found to consist of

RUYSCHIA, in botany, so named in memory of Frederick Ruysch, professor of botany at Amsterdam, a genus of the Pentandria Monogynia class and order. Essential character: calyx five-leaved; corolla five-petalled, reflexed; style none; berry many-seeded. There are two species, viz. R. clusiæfolia, and R. surubea.

RYANIA, in botany, so named in honour of John Ryan, M D. a genus of the Polyandria Monogynia class and order. Essential character: calyx five-leaved, permanent, coloured; corolla none; stigmas four; berry suberous, one-celled, many-seeded. There is only one species, viz. R. speciosa, a native of the Isle of Trinidad.

RYE. See SECALE.

RYNCHOPS, the skimmer, in natural history, a genus of birds of the order Gralla. Generic character: the bill greatly compressed; lower mandible considerably longer than the upper; nostrils linear and pervious; back toe very small; tail very forked. R. nigra, or the black skimmer, the only species, is twenty inches long, and three feet and a half in width. It inhabits America and the East Indies, and is almost incessantly on the wing, skimming over the surface of the water, into which it plunges its bill with extreme frequency, to seize small fishes, which constitute its chief food. It is a vulgar error, that the structure of its bill enables it to open oysters and other shellfish with extreme ease, and that in stormy weather it is seen on the shores opening and devouring them. See Aves, Plats XIII. fig. 3.