roundish formations on the surface of the moon, of the same nature as bulwark plains.

Rings. In gunnery, the rings of a gun are of five kinds: the base ring, reinforce ring, trunnion ring, cornice ring, and muzzle ring.

Ri'olite, in mineralogy, a substance containing selenium and zinc.

Ripie'no (Ital. full), in music, used in compositions of many parts, to distinguish those which fill up the harmony, and play only occasionally, from those which play throughout the piece.

Risus (Lat. laughter).-In pathology, risus sardonicus is a convulsive affection of the lips and cheek, which frequently precedes or accompanies tetanus;-Risus caninus is a spasmodic contraction of the muscles of one of the commissures of the lips, and of the corresponding cheek.

Ritornello (Ital. a return), in music, a short repetition, such as that of an echo, or of the last words of a song. Rivose (Lat. rivus a rivulet), in zoology, marked with furrows sinuate or not parallel.

Ko'borant (Lat. strengthening), in pharmacy, a medicine which strengthens the parts, and gives new vigour to the constitution.

Rocel'lic, in chemistry, applied to rocellic acid, a crystallized acid discovered in the Rocella tinctoria.

Rochelle Powders, a term applied to powders used for making an effervescing purgative drink when mixed in water or other liquid.

Rochelle Salt, a tartrate of soda and potassa.

Rock (Fr. roc, and Ital. rocca), a prefix of frequent occurrence in scientific words. In mineralogy, rock-butter is a native alum which occurs in soft masses in the cavities or fissures of argillaceous slate, mingled with clay and oxide of iron.-Rock-crystal is a transparent crystallized quartz.Rock-milk is an acidiferous earthy mineral, consisting of almost pure carbonate of lime.-Rock-oil, another name for petrol, or petroleum.-Rockruby, a name sometimes given to the garnet, when it is of a strong but not of a deep red.-Rock-salt, common salt found in solid masses or beds in different formations. Rock-soap, a mineral composed chiefly of silica, alumina, and water.-Rock-wood, a variety of asbestos. In conchology, rock-shells is the common name of certain univalves, characterized by the long straight canal which terminates the mouths of their shells.

Rocket (Ital.), an artificial firework, or

military projectile, consisting of saltpetre, sulphur, and charcoal, which is carried by its own conflagration to a considerable distance, and finally explodes. Congreve rockets, which are employed as military projectiles, were first invented by Sir Wm. Congreve: they are of various sizes, from twentyfour to three pounders. Rodentia, or Rodents (Lat. rodo to gnaw), an order of quadrupeds with two incisor teeth in each jaw, adapted for gnawing, as Rats, Mice, Squirrels, Beavers, Hamsters, Jerboas, Marmots, Guinea-pigs, Cavias, &c. Rolling, in mechanical science, an epithet applied to machinery, by which metals are compressed into sheets.Rolling-mill, a mill for rolling or forming iron and other metals into plates or sheets.-Rolling-press, a cylinder rolling upon another cylinder, by which printing is performed on engraved plates.

Roman, an epithet frequently applied to terms connected with mechanical science; as, Roman cement, an excellent water cement, in general use for building purposes, usually obtained from a species of ferruginous limestone. Roman vitriol is a name for sulphate of copper.-In pyrotechny, Roman candle is a particular kind of firework, characterized by the continued emission of a multitude of sparks, and the ejection, at regular intervals, of brilliant stars, which are thrown upwards as they become ignited.

Roman'zofite (from Count Romanzoff), a brown mineral from Finland. Ro'meine (from Rome de l'Isle), a hyacinth-coloured mineral, which occurs in small square octahedrons, and consists of antimonious acid, lime, protoxide of manganese, protoxide of iron, and silica: hardness, scratches glass. Dana.

Rondel (Fr. a target), in fortification, a small round tower erected in some particular cases at the foot of the bastion.

Root (Swed. rot), in botany, that part of a plant which grows downwards into the earth, while the stem ascends into the air; the smaller divisions of roots being called fibrils. - In arithmetic and algebra, the root of any quantity is an expression whose continued multiplication into itself a given number of times produces the quantity proposed. The root of an equation is any quantity which fulfils the conditions proposed in such equa

tion.

Rootstock, in botany, a prostrate stem which yearly produces young branches

Rosa'ceæ (Gr.and Lat. rosa, Celt. ros), a nat. order of exogenous plants, composed of herbaceous plants or shrubs, of which Rosa is the type and genus, distinguished by the beauty of the flowers. Don enumerates 205 species, some of which have many varieties. Rose-cut, in jewellery, an epithet applied to such precious stones as are cut with a smooth rounded surface, to distinguish them from such as have numerous facets; as, rose-diamond, a diamond cut into twenty-four triangular planes. In mineralogy, rosequartz is a variety of quartz of a rose colour.

Ro'selite (from Dr. Rose of Berlin), a very rare mineral, which occurs in small, deep rose-coloured, twin crystals, and consists of oxide of cobalt, arsenic acid, lime, magnesia, and water: H 3.0.

Rose'ola (Lat. roseus rosy), in pathology, rose-rash, a rose-coloured efflorescence, without wheals or papulæ, and not contagious.

Rosite (Lat. rosa), a rose-red mineral which occurs in small uncrystallized grains, and consists of silica, alumina, peroxide of iron, oxide of manganese, potash, lime, magnesia, soda, and water: sp. gr. 2.72; Η = 2.5.

Rostrum (Lat. the bill or beak of a bird), in surgery, a crooked pair of scissors used for dilating wounds. In chemistry, the pipe which conveys the distilling liquor into its receiver in the common alembic.

Rotheln (Germ.), in pathology, an eruptive febrile disease, partaking of the character of both scarlet fever and measles.

Rotifera, or Ro'tifers (Lat. rota a wheel, and fero to carry), in entomology, an order of Infusoria, the Wheel Animalcules, which are distinguished by certain ciliated appendages at the anterior part of the body, which seem to move in a rapid rotatory manner. Rouleaux (Fr.), in military science, a term applied to round bundles of fascines, which are tied together, and serve to cover men when the works are pushed close to a besieged town, or to mask the head of a work. Roundel (Fr.), in fortification, a circular bastion; also a kind of target. Roxburghia'ceæ, in botany, a nat. order of Dictyogens with bisexual flowers, of which Roxburghia (so called in honour of Dr. Roxburgh) is the genus. The stems have been known to attain a length of 600 feet.

Bubefa'cient (Lat. making red), in me

dicine, a substance or external application which causes redness. Ru'belite (Lat. rubeus red), red tourmaline, a mineral of a reddish colour, which consists of silica, alumina, soda, oxides of manganese and iron. Rubeo'la (Lat. redness), in pathology, an eruption of crimson-coloured stigmata or dots, grouped in irregular circles or crescents, commonly called measles.

Rubi'go (Lat. rubeus), in botany, a genus of fungous parasitic plants, popularly known by the name of mildew or blight.

Ruby (Lat. rubeus), in mineralogy, a precious stone; a crystallized gem of various shades of red, very hard and valuable. Ruby-blend is a red sulphuret of zinc.-Ruby silver, a sectile mineral, composed of sulphur, antimony, and silver.

Ru'denture (Fr.), in architecture, the figure of a rope or staff, with which the flutings of columns are sometimes filled up.

Rudolphine, in astronomy, an epithet applied to a set of astronomical tables computed by Kepler, and founded on the observations of Tycho Brahé. Ruge (Lat. folds or plaits), in anatomy,

the wrinkles or folds into which the mucous membrane of some organs is thrown in particular states.

Rule (Fr. règle, from Lat. regula), in arithmetic and algebra, a determinate mode prescribed for performing any operation. Rule of three, that rule in arithmetic which directs, when three terms are given, how to find a fourth, which shall have the same ratio to the third term as the second has to the first. Sliding-rule is a mathematical instrument serving to solve a number of questions from the change of the position of the slider by inspection, and therefore of much importance to the less educated artisan. Rumen (Lat.), in anatomy, the paunch of a ruminant quadruped. Ruminan'tia, or Ru'minants (Lat. rumino, from rumen the cud), in zoology, an order of herbivorous animals, provided with four stomachs-the first so situated as to receive a large quantity of vegetable matter, coarsely bruised by the first mastication, which passes into the second, where it is moistened and formed into little pellets, which the animal has the power of bringing again to the mouth to be re-chewed, after which it is swallowed into the third stomach, and thence passes to the fourth. It comprehends the Antelopes, Oxen, Stags, Musks, and Giraffes. Craig.

Rupia (Gr. rupis filth), an eruption of flat distinct vesicles, with a base slightly inflamed, containing a sanious fluid.

Ruta'cese (Sax. ruta or rud), a nat. order of exogenous plants, consisting of fetid herbs, as Garden Rue, of which Ruta, or Rue, is the genus. Rutel'ide (Lat. rutilans, shining), in

As an abreviation S. stands for south; S.E. for south-east; S.W. for southwest; S.S.E. for south-south-east; S.S.W. for south-south-west; F.R.S., Fellow of the Royal Society; F.G.S., Fellow of the Geological Society, &c.

Sabadilla (Sp.), in botany, a species of Veratrum found in the West Indies and in Mexico, from which veratria, a considerable article of commerce, is obtained. Sabadilline is a poisonous crystalline substance tracted from the root of the Sabadilla. Sacchar'ic Acid, a product of the action of dilute nitric acid on cane or grape sugar.

ex

Saccharine (Lat. saccharum sugar), having the qualities of sugar.-Saccharine fermentation, a kind of spontaneous fermentation which takes place in various bodies, by which sugar is formed in them either at the expense of the gluten or of an acid. Saccharite, a mineral composed chiefly of silica, alumina, soda, and lime. Saccharom'eter (Lat. saccharum, and Gr. metron a measure), an instrument for ascertaining the strength of brewers' and distillers' worts, and the richness of saccharine substances; also the degree to which the juice expressed from the sugar-cane is concentrated previously to undergoing the process of crystallization.

Saccharum (Lat. from Arab. soukar sugar), an important genus of plants from which sugar is obtained, the Sugar-cane; order Graminaceæ.-In chemistry and medicine, saccharum saturni is the acetate of lead-a salt which crystallizes in right rhombic prisms, or in needles, and is poi

sonous.

Saccholactic (Lat. saccharum, and lac milk), in chemistry, noting an acid obtained from the sugar of milk.Saccholactate is a salt formed by saccholactic acid with a base.

Sacchul'mine, in chemistry, a crystalline substance of a colour nearly black, obtained by boiling cane sugar in dilute sulphuric acid.

Sacrum (Lat. sacer sacred), in anatomy,

S.

entomology, a division of the family Scarabæides, or Sting Beetles. Ruthenium, in chemistry, a very hard brittle metal, extracted from the ore of platinum.

Rutile (Lat. rutilo to shine), in mineralogy, a reddish-brown mineral. Ru'tilite, native oxide of titanium.

the bone which forms the basis of the vertebral column. - Sacroiliac, pertaining to the articulation which exists between the sacral and iliac bones. Sacro-lumbalis, a muscle arising from the sacrum.-Sacrolumbar, pertaining to the sacro-lumbalis. Sacro-coccygeal, belonging to the articulation which results from the union of the sacrum and coccyx. -Sacro-sciatic, pertaining to either of the two ligaments of the pelvis.Sacro-vertebral, belonging to the articulation formed by the union of the sacrum with the last lumbar vertebra. Craig.

Safety Lamp, a lamp covered with fine gauze to give light in mines, and so constructed as to burn without danger in an explosive atmosphere. Safety Tube, a tube of various forms used in distillations.

Safety Valve, a valve on the boiler of a steam-engine, which opens outward from the boiler, facilitating the escape of steam.

Sagape'num (Arab.), in botany, a concrete gum resin imported from Alexandria, Smyrna, &c., in drops or masses of an olive or brownishyellow colour, used only in medicine. Sagger, a species of clay used in making the pots in which earthenware is baked.

Sagitta'lis (Lat. sagitta an arrow), in anatomy, the arrow-like suture of the cranium, which passes from the middle of the superior margin of the frontal to the angle of the occipital bone.

Sagittarius (Lat.), in astronomy, one of the signs of the zodiac, the figure of which is a centaur drawing a bow. The catalogue of the Astronomical Society gives 150 stars.

Sagittate (Lat.), in botany, shaped like the head of an arrow. Sahlite (from Sahla in Sweden, where it is found), a variety of white augite, which consists of silica, lime, magnesia, oxide of iron, manganese, and alumina.

Saint Vitus's Dance, in pathology, a convulsive motion of the limbs.

Sal (Lat.), the scientific term for salt, as used in chemistry and pharmacy.-Sal ammoniac is a compound of 17 parts of ammonia and 37 of hydrochloric acid. - Sal volatile, carbonate of ammonia, a term frequently applied to a spirituous solution of the carbonate flavoured with aromatics.

Salalem'broth, in chemistry, a double salt, consisting of chloride of mercury and chloride of ammonium.

Salam Stone, in mineralogy, a species of sapphire.

Salica'ceæ (Lat. Salix, one of the genera), a nat. order of amentaceous Exogens; the Willows and Poplars. Sal'icine (Lat. salix), a bitter crystallizable principle extracted from the willow.

Sa'lient (Lat. salio to leap), in geometry, applied to projecting angles. Sal'ifiable (Lat. sal, and fio to become), in chemistry, capable of forming a salt by combining with an acid. Saline (Lat. sal), in chemistry, containing the properties of salt. Salinom'eter (Lat. salinus saline, and Gr. metron a measure), an apparatus for ascertaining the brine in steamengine boilers.

Sali'no-terrene (Lat. salinus, and terra earth), in chemistry, partaking of salt and earth.

Sal'ivary (Lat. saliva), belonging to or conveying saliva. Salivary glands, the glands which secrete the saliva, being the parotid, sublingual, and maxillary.

Saliva'tion (Lat.), in pathology, the process of producing an excessive flow of saliva.

Salmon'idæ, a family of malacopterygious fishes, of which the Salmo, or Salmon, is the type.

Salpin'go-pharyn'geus (Gr. salpinx a trumpet, and pharynx the pharynx), in anatomy, a muscle composed of a few fibres of the palato-pharyngeus, which it assists in dilating the mouth of the Eustachian tube.

Sal Prunella (Lat.), fused nitre, cast into cakes or balls.

Salseparine', in chemistry, a substance extracted by alcohol from sarsaparilla.

Salt (Germ. salz, Lat. sal), in popular language, the chloride of sodium, a substance which has been in common use as a seasoner and preserver of food from the earliest ages.-In chemistry, any substance resulting from the combination of two oxides or analogous bodies, of which one is nighly basic and the other highly acid. Saltatoria (Lat. salto to skip), a family of orthopterous insects, comprising Grasshoppers, Crickets, &c.

Sal'tier (Fr.), in heraldry, one of the eight great ordinaries; a cross with two feet, as an X. Sal'tigrades (Lat.), a family of Spiders which leap to seize their prey. Saltpe'tre (Germ. salpeter), the nitrate of potash, a salt of very great importance, found in a natural state, but chiefly obtained by artificial pro

cesses.

Salt Rad'ical, in chemistry, an element which forms a salt by combination with a metal.

Salts, in chemistry, an important class of substances, composed of two or more dissimilar elements in such combination with each other as chemically to unite, forming a substance dissimilar to either, of which the following are a few of the more ordinary ones:-Culinary, Rock, or Sea salt, chloride of soda;-Purging or Epsom salt, sulphate of magnesia;Glauber salt, sulphate of soda;Salt of hartshorn, carbonate of ammonia;-Sedative sait, boracic acid; -Rochelle salt, tartrate of potash and soda:-Salt of Silvius, acetate of potash;-Salt of sorrel, oxalate of potash; - Microcosmic salt, triple phosphate of soda and ammonia ;Spirit of salt, hydrochloric acid;Salt of tartar, carbonate of potash; Salt of lemons, citric acid;-Salt of Saturn, acetate of lead; -Salt of amber, succinic acid;-Salt of vitriol, or White vitriol, sulphate of zinc (Craig). Salts is the popular name for salt taken as an opening medicine.

Salvatella (Germ. from Lat. salus safety), in anatomy, the name of a vein situated in the dorsal region, near the ulnar border of the human hand.

Sal Volatile (Lat. volatile salt), a sesquicarbonate of ammonia.

Samian Stone, a kind of polishing stone used by goldsmiths, brought from Samos.

Samyda'ceæ, a nat. order of exogenous plants, consisting of shrubs or little trees, of which the Samyda, or Birch, is the type.

Sand (Sax.), in mineralogy, flint or quartz broken fine by the action of water, but not reduced to powder.In chemistry, a sand-bath is a vessel filled with sand and heated by a fire underneath; -Sand-heat, the temperature produced by this apparatus. -In fortification, sand-bag is a bag containing usually about a cubic foot of sand, used in repairing breaches, erecting temporary bulwarks, &c.Sandstone is an aggregate of siliceous grains, or any stone composed

of grains of sand agglutinated together.

San'darach (Lat. sandaraca, from Arab. sandros), a resinous substance, or gum resin, which oozes from the common juniper, used in making varnish; a native fossil of a bright red colour. Sandarach is also a name for realgar, or sulphuret of arsenic.

banguina'ria (Lat. sanguis blood), in chemistry, a vegetable alkali obtained from the Sanguinaria Canadensis.

Sanguisorba'cee (Lat. sanguis, and sorbeo to absorb), an order of exogenous plants, consisting of herbs or under-shrubs, of which the Sanguisorba is the type and genus.

Sa'nies (Lat.), in physiology, a thin reddish discharge from sores or wounds.

San'tonine, a vegetable principle obtained from the Artemisia santonica. Sap (Sax.), the vital juice of plants and trees, or the fluid which is absorbed by the roots.-In military science, a trench for undermining.-Sap-green, the inspissated juice of the berries of the Buckthorn, Rhamnus catharticus. In botany, sap-tubes are those vessels by which the sap is conveyed. Sapan-wood (Malabar), the wood of the tree Casalpinia sapan, used throughout Asia as a red dye-stuff. Saphe'na (Gr. saphes distinct), in anatomy, the large vein of the leg, which ascends over the external ankle.

Sapinda'cese (Lat. sapo soap), a nat. order of exogenous plants, consisting of trees and shrubs, of which the Sapindus, or Soapwort, is the type. Saponification (Lat. sapo), the change which fats undergo in contact with alkaline solutions at high temperatures; the formation of soap.

Sap'onine (Lat. sapo), a substance contained in the root of the Saponaria officinalis, producing lather.

Sap'onite, in mineralogy, a soft white mineral.

Sapota'cese (Lat. sapo), a nat. order of exogenous plants, consisting of exotic trees or shrubs, chiefly tropical and lactescent.

Sapph'irine, a mineral which occurs in translucent grains of a pale blue or green colour, and consists of alumina, silica, magnesia, lime, oxide of iron, oxide of manganese, and water: sp. gr. 3'42; H=70-8.0. Saproph'agans (Gr. sapros putrid, and phago to eat), a tribe of coleopterous insects, comprising those which feed on animal and vegetable substances in a state of decomposition.

Sarcocarp (Gr. sarx flesh, and karpos fruit), in botany, the intermediate fleshy layer between the epicarp and endocarp.

Sarcocele (Gr.sarx, and kele a tumour), in pathology, a tumefaction of the testicle.

Sarcocol'la (Gr. sarx, and kolla glue), the concrete juice of the Penaa sarcocolla.

Sarcoderm (Gr. sarx, and derma skin), in botany, the middle covering of a seed when it becomes succulent or juicy.

Sarcolite (Gr. sarx, and lithos a stone), in mineralogy, a variety of zeolite. Sarcology (Gr. sarx, and logos a discourse), that part of anatomy which treats of the fleshy parts of the body. Sarco'ma (Gr.), in pathology, a morbid tumour.

Sarcoram'phine (Gr.sarx, and ramphos a beak), in ornithology, a sub-family of birds, of the order Accipitres. Sarco'sis (Gr. sarx), in pathology, the formation of flesh; a fleshy tumour. Sarcotic (Gr.), a medicine which fills up ulcers with new flesh.

Sard (Gr. sardion), a mineral of a deep red colour; a variety of chalcedony. Sardachate (Gr.), a sort of agate, containing sard.

Sardonyx (Gr.), a precious stone; a chalcedony or cornelian. Sarmentous (Lat. sarmentum a twig), in botany, applied to a stem which is long and almost destitute of buds or leaves.

Sarsaparil'la (Sp. zarza a bramble, and parilla a vine), a medicinal plant and its root; a species of Smilax. Sartorius (Lat. sartor a tailor), in anatomy, the muscle which serves to throw one leg across the other, called the tailor's muscle.

Sas'soline, in chemistry, native boracic acid, which occurs in loose scaly particles. The pure varieties consist of borax and oxygen: sp. gr. 1'48. The name is derived from Sasso, at the hot springs of which it is deposited.

Satellite (Lat. satelles an attendant), a secondary planet which revolves about a primary planet, as the moon round the earth.

Satin-spar, in mineralogy, fibrous limestone.-Satin-wood, a fine lemoncoloured wood, having a fragrant odour.

Saturation (Lat.), in chemistry, the union of one body with another by affinity, till the receiving body can contain no more.

Saturn, in astronomy, one of the primary planets of the solar system, which is attended by seven satellites.