quesces.

NITROUS acid. It has already been observed, that there is no such thing, properly speaking, as nitrous acid, or the nitric base acidified with a minimum dose of oxygen; but that the nitric acid is capa ble of absorbing various portions of nitric oxide, with which it parts very readily, so that when in considerable quantity it gives it out in the ordinary state of the air, on mixing with which it assumes the appearance of a very red vapour. Hence it was formerly called fuming nitrous acid. It appears, however, to be capable of combining with some at least of the salifiable bases, so as to form a distinct genus of salts, that may be temed nitrites. But these cannot be formed by a direct union of their component parts; being obtainable only by exposing a nitrate to a high temperature, which expels a portion of its oxygen in the state of gas, and leaves the remainder in the state of a nitrite, if the heat be not urged so far, or continued so long, as to effect a complete decomposition of the salt. In this way the nitrates of potash and soda may be obtained, and perhaps those of barytes, strontian, lime, and magnesia. The nitrites are particularly characterized by being decomposable by all the acids except the carbonic, even by the nitric acid itself, all of which expel from it nitrous acid. We are little acquainted with any one except that of potash, which attracts moisture from the air, changes blue vegetable colours to green, is somewhat acrid to the taste, and

when powdered emits a smell of nitric oxide.

NITROUS oxide. See GAS.

NOBILITY, a quality that ennobles, and raises a person possessed of it above the rank of a commoner. The origin of nobility in Europe is by some referred to the Goths; who, after they had seized a part of Europe, rewarded their captains with titles of honour, to distinguish them from the common people. In Britain the term nobility is restrained to degrees of dignity above knighthood; but every where else nobility and gentility are the same, The British nobility consists only of five degrees, viz. that of a duke, marquis, earl or count, viscount, and baron, each of which see under their proper articles. In Britain these titles are only conferred by the King, and that by patent, in virtue of which it becomes hereditary. The "privileges of the nobility are very considerable, they are all esteemed the King's hereditary counsellors, and are privileged from all arrests, unless for treason, felony, breach of peace, condemnation in parliament, and contempt of the king. They enjoy their seats in the House of Peers by descent, and no act of parliament can pass without their concurrence: they are the supreme court of judicature, and even in criminal cases give their verdict upon their honour, without being put to their oath. In their absence they are allowed a proxy to vote for them, and in all places of trust are permitted to constitute deputies, by reason of the necessity the law supposes them under of attending the King's person; but no peer is to go out of the kingdom without the King's leave, and when that is granted, he is to return with the King's writ, or forfeit goods and chattels.

NOBLE, a money of account containing six shillings and eight-pence. The noble was anciently a real coin struck in the reign

of Edward III. and then called the penny of gold; but it was afterwards called a rose noble, from its being stamped with a rose.

NOCTURNAL, something relating to the night, in contradistinction to diurnal.

NOCTURNAL arch, in astronomy, the arch of a circle described by the sun, or a star, in the night.

NOCTURNAL, Semi, arch of the sun, is that portion of a circle he passes over between the lower part of our meridian and the point of the horizon, wherein he arises; or between the point of the horizon wherein he sets, and the lower part of our meridian.

NOCTURNAL, or NOCTURLABIUM, an instrument chiefly used at sea, to take the altitude or depression of some stars about the pole, in order to find the latitude and hour of the night. Some nocturnals are hemispheres, or planispheres, on the plane of the equinoctial. Those commonly in use among seamen are two; the one adapted to the polar star, and the first of the guards of the little bear; the other to the polestar, and the pointers of the great bear.

This instrument consists of two circular plates applied to each other. The greater, which has a handle to hold the instrument, is about two inches and a half diameter, and is divided into twelve parts, agreeing to the twelve months, and each month subdivided into every fifth day; and so as that the middle of the handle corresponds to that day of the year wherein the star here regarded has the same right ascension with the sun. If the instrument be fitted for two stars, the handle is made moveable. The upper left circle is divided into twentyfour equal parts for the twenty-four hours of the day, and each hour sub-divided into quarters. These twenty-four hours are noted by twenty-four teeth to be told in the night. Those at the hours twelve, are distinguished by their length. In the centre of the two circular plates is adjusted a long index, moveable upon the upper plate. And the three pieces, tiz, the two circles and index, are joined by a rivet which is pierced through the centre with a hole, through which the star is to be observed.

"To use the Nocturnal," turn the upper plate till the long tooth, marked twelve, be against the day of the month on the under plate: then, bringing the instrument near the eye, suspend it by the handle with the plane nearly parallel to the equinoctial; and viewing the pole-star through the hole of the centre, turn the index about till, by the edge coming from the centre, you see the bright star or guard of the little bear (if the instrument be fitted to that star): then that tooth of the upper circle, under the edge of the index, is at the hour of the night on the edge of the hour circle: which may be known without a light, by counting the teeth from the longest, which is for the hour twelve.

NODE, in surgery, a tumor arising on the bones, and usually proceeding from some venereal cause; being much the same with what is otherwise called exostosis.

NODES, in astronomy, the two points wherein the orbit of a planet intersects the

ecliptic, whereof the node, where the planet ascends northwards, above the plane of the ecliptic, is called the ascending node, the northward node, and the head of the Dra. gon, and is marked thus & ; the other node, where the planet desends to the south, is called the descending node, the southward node, or the Dragon's tail, marked thus 8.

The line wherein the two circles intersect, is called the line of nodes. It appears from observation, that the line of the nodes of all the planets constantly changes its place, and shifts its situation from east to west, contrary to the order of the signs; and that the line of the Moon's nodes, by a retrograde motion, finishes its circulation in the compass of nineteen years; after which time, either of the nodes having receded from any point of the ecliptic, returns to the same again; and when the Moon is in the node, she is also seen in the ecliptic. If the line of nodes were immoveable, that is, if it had no other motion than that whereby it is carried round the Sun, it would always look to the same point of the ecliptic, or would keep parallel to itself, as the axis of the earth does.

From what has been said, it is evident that the Moon can never be observed precisely in the ecliptic, but twice in every period; that is, when she enters the nodes. When she is at her greatest distance from the nodes, viz. in the points, she is said to be in her limits. The Moou must be in or near one of the nodes, when there is an eclipse of the Sun or Moon.

NOLANA, in botany, a genus of the Pentandria Monogynia class and order. Natural order of Asperifoleæ, or Luridæ. Borragineæ, Jussieu. Essential character: corolla bell-shaped; style among the germs; seeds five, berried, two-celled. There is but one species, viz. N. protrasta, trailing nolana.

NOLLE prosequi, is used where the plaintiff will proceed no further in his action, and may be as well before as after a verdict, and is stronger against the plaintiff than a nonsuit, which is only a default in appearance; but this is a voluntary acknowledgment that he has no cause of action. In criminal cases it can only be entered by the Attorney General.

NOLLET (JOHN ANTHONY), in biography, a French ecclesiastic and celebrated natural philosopher in the eighteenth cen tury, was born at Pimprè, in the diocese of Noyon, in the year 1700. His parents, who

were persons of reputable character, though of humble fortunes, as they could not make him wealthy, determined to bestow on him the advantages of a good education. With this view they sent him to the college of Clermont in the Beauvoisin, and afterwards to Beauvais, where he laid a good foundation of grammar learning, which encouraged them to send him to Paris, in order to go through a course of philosophy at that university. It was their wish that he should embrace the ecclesiastical profession, and young Nollet adopted without repugnance the choice which they made for him. From a very early age he had shewn a taste for the study of natural philosophy, which had not yet become his ruling passion; he was, therefore, enabled to check himself in a pursuit which was likely to interfere with the studies more appropriate to his destined character, and gave himself up entirely to the study of scholastic theology. Having completed his academical course, and pas. sed with reputation through the usual examinations, in 1728 he was admitted to deacon's orders, and soon became a licensed preacher. This new occupation, however, did not wholly divert his attention from the subjects of his early inquiries, and they insensibly claimed more and more of his time. At length his inclination for the sciences became irresistible, and he gave himself up to the study of natural philosophy with an ardour to which the kind of privation in which he had so long lived gave augmented force. It was now his good fortune to become known to M. du Fay and M. Reaumur, and under their instructions his talents were rapidly developed. By the former he was received as an associate in his electrical researches and the latter resigned to him his laboratory. He was also received into a Society of Arts, established at Paris under the protection of the Count de Cler mont. In the year 1734, he accompanied M. M. du Fay, du Hamel, and de Jussieu, on a visit to England, where he had the honour of being admitted a foreign member of the Royal Society, and he profited so well of this visit, as to institute a friendly and literary correspondence with some of the most celebrated men in this country. Two years afterwards he made a tour to Holland, where he formed an intimate connection with 8'Gravesande and Musschenbroek. Upon his return to Paris, he resumed a course of experimental philosophy, which he commenced in 1735, and which he continued to the year 1760. These courses

of experimental physics gave rise to the adoption of similar plans in other branches of science, such as chemistry, anatomy, natural history, &c.

In the year 1738, the Count de Maurepas prevailed upon Cardinal Fleury to establish a public professorship of experimental philosophy at Paris, and the Abbé Nollet was the first person who received that appointment. During the following year, the Royal Academy of Sciences appointed him adjunct mechanician to that body; and in 1742 he was admitted an associate. In the year 1739, the King of Sardinia being desirous of establishing a professorship of physics at Turin, gave an invitation to the Abbé Nollet to perform a course of experimental philosophy before the royal family, with which he complied. From Turin he took a tour to Italy, where he collected some good observations concerning the natural history of the country. In the year 1744, he had the honour of being called to Versailles, to give lessons in natural philosophy to the Dauphin, at which the King and royal family were frequently present. By the excellence and amiableness of his personal character, as well as by his scientific talents, he recommended himself to the confidence of his illustrious pupil, who continued as long as he lived to express the greatest esteem for our philosopher. It is to be lamented that his liberality did not prompt him to better the mediocrity of his tutor's fortune. In the year 1749, the Abbé Nollet took a second journey into Italy, whence wonderful accounts had been circulated throughout Europe, of the communication of medicinal virtues by electricity, which seemed to be supported by numerous wellattested facts. To examine into these facts, and to be assured of their truth or fallacy, was one grand motive with our author in passing the Alps at this time, and in visiting the gentlemen who had published any ac counts of those experiments. But though he engaged them to repeat their experi. ments in his presence, and upon himself, and though he made it his business to get all the information which he could concerning them, he was soon convinced that the pretended facts were deceptions or exaggerations, and that no method had been discovered, by means of which the power of

medicine could by electricity be made to insinuate itself into the human body. But these wonders were not the only objects which engaged our Abbe's attention in this visit to Italy; for his inquiries were extend

ed to all the branches of natural philosophy, the arts, agriculture, &c. On his return to France, through Turin, the King of Sardi nia made him an offer of the order of St. Maurice, which he thought it his duty to decline, not having the permission of his own sovereign for accepting it. In the year 1753, the King established a professorship of experimental philosophy at the Royal College of Navarre, and nominated the Abbé Nollet to fill that post. In the year 1757, the King bestowed on him the brevet of master of natural philosophy and natural history to the younger branches of the royal family of France; and in the same year appointed him professor of natural philosophy to the schools of artillery and engineers. Soon after this last preferment, he was received a pensionary of the Royal Academy of Sciences. This celebrated and laborious natural philosopher died in 1770, in the seventieth year of his age, regretted by the enlightened public, as well as the numerous friends whose attachment he had secured by the amiableness of his manners and the goodness of his heart; and more especially regretted by his poor relations, to whose relief and comfort he always paid the most affectionate attention. Besides the Royal Society of London, and the Royal Academy of Sciences at Paris, he was a member of the Institute of Bologna, the Academy of Sciences at Erfurt, and other philosophical societies and academies.

12mo.

In addition to a multitude of papers inserted in the different volumes of the "Me. moirs of the Academy of Sciences," from the year 1740 to the year 1767, both inclusive, the Abbé Nollet was the author of "Lessons on Experimental Philosophy," in six volumes, 12mo. "A Collection of Letters on Electricity," 1753, in three volumes, "Enquiries into the particular Causes of Electric Phenomena," 12mo.: and "The Art of making Philosophical Experiments," in three volumes, 12mo. From the articles just enumerated, as well as an anecdote already related in his life, it appears that Abbè Nollet paid particular attention to the study of electricity; and it must be acknowledged, notwithstanding the mistakes which he fell into upon the subject, that his indefatigable industry and curious experiments contributed materially to the improvement of that science. The theory of Affluences and Effluence of this philosopher, which gained considerable attention in his time, may be seen in Priestley's Electricity.

NO-man's-land, a space in midships, be, tween the after-part of the belfry and the fore-part of a boat, when she is stowed upon the booms, as in a deep waisted vessel. These booms are laid upon the forecastle nearly to the quarter-deck, where their after-ends are usually sustained by a frame, called the gallows, which consists of two strong posts, about six feet high, with a cross piece reaching from one to the other athwart ships, and serving to support the ends of those booms, masts, and yards, which lie in reserve to supply the place of others carried away, &c. The above-named space is used to contain any blocks, ropes, tackles, &c. which may be necessary on the forecastle, and probably derives the name of no-man's-land from its situation, as being neither on the starboard nor larboard side of the ship, nor on the waist nor forecastle; but being situated in the middle, partakes equally of all those places.

NOMENCLATURE, a catalogue of several of the more usual words in any language, with their significations, compiled in order to facilitate the use of such words, to those who are to learn the tongue: such are our Latin, Greck, French, &c. nomenclatures.

NOMINATIVE, in grammar, the first case of nouns which are declinable. The simple position or laying down of a noun, or name, is called the nominative case; yet it is not so properly a case as the matter or ground whence the other cases are to be formed, by the several changes and inflec tions given to this first termination. Its chief use is to be placed in discourse before all verbs, as the subject of the proposition or affirmation.

NONAGISMAL, in astronomy, the 90th degree of the ecliptic, reckoned from the eastern term, or point. The altitude of the nonagesimal is equal to the angle of the cast, and, if continued, passes through the poles of the ecliptic; whence the altitude of the nonagesimal at a given time, under a given elevation of the pole, is easily found. If the altitude of the nonagesimal be sub. stracted from 90°, the remainder is the distance of the nonagesimal from the vertex.

NONAGON, in mathematics, a figure having nine sides and angles. In a regular nonagon, or that the sides and angles of which are equal, if each side be 1, its area will be 6.132 nearly = 4 of the tangent of

70' to the radius.

NON claim, in law, where a person has a