NITROGEN. incombustible, nor does it support combustion. It is not directly poisonous, yet it is incapable of supporting life, inasmuch as it cuts off the entrance of the life-supporter oxygen. By reason of its inertness and general slowness of chemical action it acts the part of a diluent of oxygen in the atmosphere. Having no marked action of its own on living beings, its admixture with the oxygen of the air serves to moderate the otherwise too violent action of this latter gas. Under certain circumstances nitrogen may be induced to combine with other elements, especially with hydrogen, oxygen, and carbon, with titanium, tantalum, and tungsten. This gas, nitrogen, is allied in many of its chemical properties to the other elementary substances-phosphorus, arsenic, antimony, and bismuth; it has the power of combining with one, three, or five atoms of a monovalent element or radicle, and its atomic weight is 14. NITROGEN, OXIDES AND OXIACIDS OF. oxides of nitrogen are a very interesting series of The bodies, five in number. It is by looking at these substances as a series rather than by regarding each of them in detail that their interesting nature is chiefly brought to view. The first oxide of nitrogen contains 28 parts by weight of nitrogen united with 16 parts by weight of oxygen; its chemical formula is NO. The next oxide contains 28 parts by weight of nitrogen united with 32 parts by weight of oxygen; its formula is NO. In the third oxide the same amount of nitrogen, 28 parts, is united with 48 parts of oxygen, and to it the formula NO, is assigned; while the fourth and fifth oxides contain respectively 64 and 80 parts of oxygen, united in each case with 28 of nitrogen; to these the formula N20, and N2O, are given. Now why is it that in these oxides the amount of oxygen increases by multiples of 16? Why do we have either 16, or twice or three times 16, parts of oxygen combined with the same amount of nitrogen? Why is it not possible to form an oxide of nitrogen which shall contain 16 plus the half or fourth of 16 parts of oxygen in union with 28 parts of nitrogen? Questions such as these led John Dalton to his famous atomic theory (which see), which supposes that the atom, or smallest chemically indivisible part of oxygen, weighs, relatively to hydrogen as unit,-16, also that chemical combination takes place atom with atom; hence it is impossible to have any compound containing a fraction of an atom, that is, in the case before us, any fraction of 16 parts by weight of oxygen. These oxides of nitrogen may be all produced from nitric acid. The highest oxide, NO, called nitrogen pentoxide, is formed by the action of dehydrating substances, notably phosphorus pentoxide (the white substance produced by burning phosphorus in air), on strong nitric acid, 2 HNO-H2O = NO. This oxide forms colourless, transparent crystals, which melt at 30°, and boil a little above 45°. From its great avidity for water it is somewhat difficult to prepare this body. The next lower oxide (NO), called nitrogen tetroxide, may be produced by forming the lead salt of nitric acid and heating this salt in a glass retort, when red fumes are evolved, which may be condensed by cold, forming thereby a nearly colourless liquid. When cooled to -9° this liquid solidifies, and we thus obtain colourless, transparent prismatic crystals. When the liquid is heated its colour gradually changes to darker and darker red, until it finally becomes very dark. These changes are probably accompanied by a decomposition of the molecule NO, into two molecules, each represented by the formula NO. The trioxide (NO) is produced, although not unmixed with other oxides, when nitric acid is heated with starch and the dense red fumes are led into a tube surrounded with a freezing-mixture. This oxide forms a dark blue liquid, which, when added to water HNO2. This solution acts as a reducing agent, inasat 0°, combines therewith, forming nitrous acid, much as it eliminates gold and mercury as metals from cises an oxidizing action on such salts as ferrous sulseveral of their salts; on the other hand, it also exerphate, potassium iodide, &c. By replacement of the hydrogen in nitrous acid a series of metallic salts is obtained, called nitrites. general formula MNO, where M represents a monoThese nitrites have the valent metal. Nitrites, especially ammonium nitrite, partial oxidation of nitrogenous substances. When are met with in nature; they are produced by the pure water evaporates into the atmosphere it takes up a small quantity of nitrogen, and forms thereby ammonium nitrite, thus 2 H2O + N2 NH,NO. = The next lower oxide of nitrogen, namely, nitrogen acting on copper with nitric acid diluted with its own dioxide (NO), called also nitric oxide, is produced by bulk of water. Nitrogen dioxide is a colourless, permanent gas. With oxygen this substance forms the trioxide, thus N2O + 0 = N2O, hence whenever nitrogen dioxide is brought into contact with air red fumes (nitrogen trioxide) are produced. NO; it is better known by the name of 'laughingThe last oxide, nitrogen monoxide, has the formula gas,' from the peculiarly exhilarating effect which it produces when breathed along with a little air. If total insensibility, which does not continue long, and the gas be pure, its inspiration soon brings about generally produces no bad effects upon the person who breathes it, hence it is much used as an anæs. thetic in minor surgical operations, such as teethgenerally liquefied by pressure, and stored in thick drawing, &c. For the use of the dentist the gas is iron cylinders, from which, when opened at ordinary Nitrogen monoxide is prepared by heating the amtemperatures, a copious stream of gas is obtained. monium salt of nitric acid, thus = NH,NO, N2O + 2H2O. An acid corresponding to this oxide, and called hyponitrous acid, is known. It may be regarded as the product of the action of water on the oxide; NO + H2O = 2HNO, in the same way as nitrous acid is the product of the action of water on the higher oxide, namely, the trioxide, N2O3 + H2O = 2HNO2, the case of nitrogen pentoxide, NO+H20=2HNO, and as nitric acid is the product of the same action in This last-named acid-nitric acid-we have now to consider. nitre (potassium nitrate) or Chili saltpetre (sodium Nitric acid has the formula HNOS. By distilling nitrate) with strong sulphuric acid nitric acid is obtained, KNO, + H2SO, = KHSO, + HNO. The sodium salt is more generally employed by the manufacturer, because 85 parts by weight of this substance produce as much of the acid as 101 parts of nitre, the amount of sulphuric acid required being the same in both cases. teenth century. As the process proceeds a yellow, or This process is almost identical with that by which Glauber obtained the acid in the sevensometimes reddish yellow, liquid is found in the receivers. This liquid is nitric acid mixed with oxides of nitrogen; from these oxides it may be freed by blowing a current of air through it. When pure, nitric acid forms a mobile, colourless liquid which fumes strongly in the air, is very acid, burns the hand, staining the skin yellow, and absorbs moisture from the air. When cooled to -55 it becomes gradual decomposition, until at 260° it is entirely thick and semi-solid. broken up into water, nitric oxide, and oxygen. When heated it undergoes Nitric acid contains about 76 per cent. of oxygen, NITROMURIATIC ACID-NOAILLES. a great part of which it readily gives up to other substances, acting thus as a powerful oxidizer. Thus many metals such as copper, tin, silver, &c.—when brought into contact with this acid, are oxidized at the expense of the acid, with the production of lower oxides of nitrogen and an oxygenated metallic salt. Similarly, if turpentine be dropped into very strong nitric acid the carbon and hydrogen of the turpentine are oxidized so energetically that light and heat are produced. Nitric acid, when moderately dilute, acts on organic bodies so as to produce a series of most useful substances, notably acetic, oxalic, and picric acids, isatin or white indigo, &c. When strong acid is used, nitro-compounds oftentimes result, containing the group NO, in place of part of the hydrogen of the original substance; thus we get nitrophenol, nitrobenzene, &c. By replacement of the hydrogen in nitric acid a series of salts termed nitrates is obtained, which may be represented by the formulæ MNO, and Ma(NO3)2 where M stands for a monovalent metal. Many of the nitrates are much used in the arts; they are generally crystalline substances, easily soluble in water. These salts decompose when strongly heated, at first generally evolving oxygen, and, as the temperature When nitrates rises, nitrogen tetroxide or trioxide. are heated with combustible bodies an explosion is generally produced. For a description of the different metallic nitrates reference must be made to the articles on the various metals. A mixture of strong hydrochloric and nitric acids is known as aqua regia, nitromuriatic, or nitrohydrochloric acid; it is much used as a powerful oxidizing substance; its action depends chiefly on the chlorine and chloride of nitrosyl (NOC) which it evolves. These substances readily decompose water and evolve oxygen, which in this so-called nascent state is very powerful in its action. In addition to these oxi-derivatives of nitrogen a series of haloid derivatives are known, produced by the action of iodine, chlorine, or bromine upon compounds of nitrogen, especially upon ammonia. These substances are extremely explosive, a few drops of nitrogen chloride being sufficient, when exploded, to They shatter the entire contents of a large room. have not, as may be expected, been much studied; the formulæ NC, and ÑI, are usually assigned to the chloride and iodide respectively. NITROMURIATIC ACID. See Aqua Regia under NITROGEN, NITROPHENOL. See PHENOL. NITROSO-COMPOUNDS. The action of nitrous R.NH+NO.OH = HOH+RN.NO. NOAH, one of the patriarchs of the Old Testa- VOL. V. the father of the new race of men which should NOAILLES, one of the oldest noble families in 256 elder marshal, to serve under him in the battle of Fontenoy. He was ambassador to Madrid from April to June, 1746. In later times the following members of this family have rendered themselves distinguished :— LOUIS MARIE ANTOINE (1756-1804), Viscount of Noailles, a general, and member of the first national convention in 1789. After the dissolution of the Constituent Assembly he went into the army, and in 1792 commanded the chain of outposts at Valenciennes. His birth subjected him to suspicion; he demanded his dismissal, and lived in retirement in the country. Under the consular government he returned to the service, and gained distinction in St. Domingo as general of brigade under Leclerc and Rochambeau. After the evacuation of the island he embarked on board a vessel of war for Cuba, but was killed in a fight with the British, who took the vessel. His son ALEXIS, Count of Noailles (1783-1835), minister of state of Louis XVIII., was obliged to leave France in 1811. In 1813 he served under the Crown-prince of Sweden in Germany. He acted as the plenipotentiary of Louis XVIII. at the Congress of Vienna. He returned with the king from Ghent to Paris, was chosen deputy of the chamber of 1815, and in October of the same year was appointed by Louis minister of state, but without any particular department. In 1828 he was a member of the chamber of deputies, and was appointed by the king member of the commission to examine whether the schools of the clergy accorded with the principles of the French constitution. NOBILITY, a rank of society which possesses honours and privileges above the rest of the citizens. A hereditary nobility is found in the infancy of almost every nation, ancient and modern, for there is in society a natural tendency to inequality of condition. Its origin is to be attributed to various causes: for the most part to military despotism; in some cases to the honours paid to superior ability or to the guardians of the mysteries of religion. The priestly nobility of the remotest antiquity has everywhere yielded to the superiority of military chieftains. Among the ancient Romans the citizens were at first either nobiles or ignobiles, that is, patricians or plebeians; but a new order of nobility arose out of the plebeians, the descendants of those who had held curule magistracies being entitled to exercise the jus imaginum, or right of having images of their ancestors—a distinction corresponding to the modern one of having coats-of-armour. Among the ancient German tribes only obscure traces of hereditary nobility are found, which in later periods was generally established throughout the Continent. Many of them seem, however, to have recognized one ruling family. Besides these, no other hereditary nobility existed among the Franks, Saxons, Normans, Danes, Swedes, and most of the other nations of the north. The Athelings of the Saxons are exclusively members of the reigning house, and the same name frequently denotes only the successors to the throne. The dignities of the counts of the Franks, the aldermen and great thanes of Britain, as also of the jarls (in England Eorlas) of Denmark, were accessible to every one distinguished by merit and favoured by fortune. In France and Germany the first hereditary nobility begins with the downfall of the Carlovingian dynasty; in England with the important conquest of the Normans in the eleventh century. (See BRITAIN-The Civil State.) It was afterwards spread over all Europe, for since that time dignities as well as lands have become hereditary. Under various forms and combinations the nobles of the first rank (as princes, counts, and lords), together with the warriors (consisting of knights bound to do service in war and at the court), which latter were not always considered as perfectly free, were distinguished from the peasants and common citizens, who were bound to perform the common laborious services. The further progress of these civil distinctions and their relations to the people took a very different course in the different countries of Europe. In England hereditary nobility, including various classes of titles, for example, those of dukes, marquises, earls, viscounts, and barons, is personal. In Spain and Italy, on the other hand, the same rank (that of the titulados-princes, dukes, marquises, and counts) depends in a greater measure upon property, for these titles, though sometimes conferred by the monarchs, are mostly connected with estates, and often attached to very small fiefs; hence the multitude of counts in Upper Italy, the conti di terra ferma of Venice in former times. The distinguished Spanish families collect in this manner a great number of such titles, which constitute an object of their pride. In France nobility is common to all the members of the noble family. The rights of the peerage and the feudal estates, however, descended, even before the revolution, only to the eldest son; and the younger sons usually sought their fortune either in the ariny or the church. Every meaner employment, even mercantile business, was followed by the loss of nobility; but this was not the case in England or Scotland. The nobility of England has never risen to sovereignty, except that some provinces which formerly were domains of princes of the royal family (as Lancaster, Cornwall), and some viscounties (Durham, Chester, the Isle of Ely, and especially the Isle of Man, belonging to the dukes of Athol), enjoyed, as counties palatine, so called, subordinate rights of government. The sovereignty connected with the ancient fiefs of the French princes-as the dukedoms of Normandy, Bretagne, Guienne, Burgundy; the counties of Toulouse, Champagne, Flanders; and the territories of Dauphiné, Provence, Franche-Comté, Venaissin, &c.-took its rise at a very early period, and had already become complete when Hugh Capet ascended the throne. But France was fortunate enough to unite by degrees all these extensive fiefs with the crown, so that only a few small sovereignties (as the princedoms of Bouillon, Dombes, Orange, Avignon, Venaissin, and a few more) maintained themselves as such to more recent periods. In the age of Louis IX. appeals from the courts of the barons to the supreme courts of the king and parliaments were introduced, and were followed by a gradual extension of the king's authority over the territories of the barons; and finally, under the reign of Louis XIII. the power of the grandees was completely destroyed by Richelieu. The course which the nobility took in Germany was different. Here the ancient Dukes of Saxony, Bavaria, Franconia, Suabia, Lotharingia, and, next to them, the margraves in the east and north of the German Empire, obtained at the same time as in France the rights of sovereignty; and the title of count became partly hereditary, partly an appendage to the ecclesiastical establishments. The emperors succeeded in annihilating these ancient principalities, but profited little by it, for new sovereignties soon took the places of the ancient dukedoms, inferior in size and power, but equal to them in the extent of their rights and privileges. The greater number of the counts assumed the rights of sovereignty, and a vast number of ruling families thus sprang up in Germany, and formed a ruling order of nobility, in which not only the rank but also the property was hereditary, and became the common inheritance of the whole family. In Germany it was a recognized principle that the mother must be of equal rank with the father in are not uncommon. NOBILITY. order to place her children in the full possession of their father's rights. Many even princely families, as Baden, Anhalt, &c., have transgressed this principle; but others adhered to it with great strictness. The same principle has been extended to the lower class of the German nobility. In their case, however, it affects only the enjoyment of certain privileges common to the whole body of nobility-privileges by which the German nobility is more strictly distinguished from the middle classes of freemen than that of any other country. In the rest of Europe not even the highest class of nobility recogIn France the royal alone nizes this principle. afforded no example of a marriage contracted with persons of a lower rank, though the law would not have interfered. The legitimated branches of the royal family, the offspring of mistresses, the princes of Vendôme, Verneuil, Vermandois, Maine, Toulouse, Penthièvre, &c., which are now extinct, Louis XIV. did not hesitate in his will to recognize as capable of succession to the French throne in spite of their descent not merely from parents of unequal rank but even from an illegitimate connection; and the same right could never have been contested in regard to children of a legitimate connection between parents of unequal rank. In the noble families of France the rank of the mother was likewise of no consequence; the whole importance of the family rested on the lineage of the father. The same is the case in England, where intermarriages between the families of ordinary citizens and the highest nobility Similar examples may be found in other countries. In Germany alone the interests of the kindred of princes as well as the exclusive claims of the nobility to the chapters and prebends of the ecclesiastical orders have produced those rigid principles above-mentioned. Germany is likewise the only country which affords an example of a select nobility composed of reigning families and princes, who, besides the right of sovereignty over their own territories, had a part in the government of the empire by their seat and vote in the diet, or at least a share in the collective vote of the prelates or of the four bodies of counts, for some rights of Sovereignty belonged also to the knights of the empire who did not belong to the select nobility. The limits of this select nobility were extremely uncertain and contested, though very important to be settled, on account of the restrictions on the The rank of the select marriage of its members. nobility was partly personal, partly hereditary. The former was attached to ecclesiastical princes, bishops, and abbots, many of whom were at the same time actual sovereigns; but many possessed only the dignity of princes of the empire without the rights of sovereignty. In most of these ecclesiastical principalities the German nobility had excluded untitled men of learning and talent against the will of the pope and his express order promulgated in the The highest degree of hereTreaty of Westphalia. ditary nobility was peculiar to the families of the princes and counts of the empire, and confined to Germany. It is true many French, Italian, Spanish, and English families had the title of princes, dukes, and marquises (English dukes and marquises are also called princes in official documents), but the German princes considered few of them as their equals. To this class belong in France those six foreign families which enjoyed at the French courts the rights of princes étrangers on account of their relationship with sovereign houses or on account of their descent from former sovereigns of Bretagne and Aquitania. These families in France were those of Lotharingia, Savoy, Grimaldi (princes of Monaco), Rohan, Latour d'Auvergne (dukes and princes of Bouillon). Some In Sweden and DenPolish families belonged also to this class, as the Radzivills, Czartoryskis, &c. mark a select nobility of this kind has never existed. Though many German families of this rank had lost their sovereignty, yet the act of the German Confederation conceded to them the highest rank of nobility, equal to that of the sovereign houses. There was still a strict distinction in Germany between the ancient princes who had risen to this dignity before 1580 and those of a more recent date. The more, however, the power of the German princiOn this account a society was palities increased the more the importance of the nobility decreased. formed in 1815 called the chain of nobility, for the The purpose of restoring and promoting the interests of the nobles; but it met with little success. nobility of France under the restored Bourbons, and during the first part of the reign of Louis Philippe, were of two classes-the titular only, and those both titular and legislatorial; the latter formed a majority in the chambre des pairs. The British nobility composing the House of Lords consists of five ranksduke, marquis, earl, viscount, baron. The Russian nobility, though its origin is not directly derived from Germany, has appropriated to itself all its As soon as the nobles had asferred by patent. degrees and titles. Nobility was very early consumed the character of a distinct rank in the state the monarchs also availed themselves of their right of conferring degrees of nobility, and insisted upon the principle that in a monarchy no privilege could be more ancient or could have any other origin than the prerogative of the monarch himself. Philip III., nobility in France, and Germany soon followed his therefore, first began (1271) to grant charters of example. The degrees of the lower nobility in Ger4. Bannerherr; 5. Freyherr; 6. Graf. Their privimany were, 1. The title Von; 2. Edler von; 3. Ritter; several countries they were enlarged to a considerleges were originally of little importance; but in tice. They enjoyed immunity from taxes and an able extent by law as well as by custom and pracexclusive right to the highest public offices, especially in the army. The most important of these privileges have in modern times either been limited or entirely abolished because they were inconsistent state. The French revolution first deprived the with justice and an obstacle to the prosperity of the nobles of that country of their oppressive privileges and exclusive rights, as that of jurisdiction, &c. (decree of August 4, 1789); and after the overthrow of June 19, 1790, abolished hereditary rank entirely. of the feudal system by a number of laws the decree The senate under Napoleon (August 14, 1806) and the decree of March 1, 1808, gave rise to a new After the restorahereditary nobility, with the titles of princes, dukes, counts, barons, and chevaliers, which descended, tion of the Bourbons (1814) the ancient nobility however, only to the eldest son. reclaimed their former rights and privileges. In successive decrees of 1815, 1818, and 1821. Norway the Storthing abolished nobility by the three France hereditary nobility was suppressed by the chamber of deputies on 10th October, 1831. The nobility of Scotland and Ireland have had their privileges limited and defined by the acts of union, that of the former with England in 1707 and that of Ireland with Great Britain in 1800. The higher nobility of England have seats in the upper house elect peers of Parliament, while the Scottish peers elect sixteen of their number to represent their order in the upper house in each Parliament, and the Irish twenty-eight representatives for the same purpose. No new Scotch peerages could be created, but only peers of Great Britain, either in England or Scotland, In NOBLE-NODE. from the time of the union of England with Scotland and that with Ireland; and in the three kingdoms, since the union with Ireland, all new peers are peers of the United Kingdom. On the extinction, however, of three existing Irish peerages another may be created, and when the Irish peerage is reduced to 100 a new peerage may be created on the extinction of one of these. A Scotch peer, who is not one of the sixteen representative peers, cannot sit in the House of Commons-a disability not extending to non-representative Irish peers. The ranks of the peerage are being continually recruited, the selection for the most part falling on Scotch or Irish peers or on the unennobled members of noble families; on persons distinguished for eminent public services; on lawyers who have been promoted to high judicial appointments; on persons of extensive property and old family; and sometimes, though rarely, on persons who have acquired great wealth and consequent influence from the successful prosecution of commerce, mining, or manufacturing. NOBLE, an ancient English gold coin, value six shillings and eightpence, first struck in the reign of Edward III., 1344. NOCTILUCA. The Noctiluca miliaris is one of the Protozoa, possessing an intimate structural relationship with the Infusorian animalcules of that sub-kingdom. This animalcule, which is of minute or microscopic size, is one of those animal forms which possess the power of emitting the phosphorescent light so familiar to all who have sailed on the sea at night. Each movement of the vessel, or each breath of wind rippling the surface of the ocean, produces strange gleams of phosphorescent light, which sweep across the sea. The property of producing this light appears to reside in other animals besides the Noctiluca-for example, Medusida or Jelly-fishes, Annelides, &c.-but these animalcules are the chief cause of the diffused light seen over the general surface of the ocean, and they thus exist in immense multitudes in the waters of the sea. The technical or generic name of these forms-Noctiluca (Latin, nor, night; luceo, I shine) is derived from this circumstance. The minute body, averaging th of an inch in diameter, is somewhat ovoid or spherical in shape, and is indented by a 'hilum' or cleft at one side, this structure giving it a somewhat kidney-like conformation. A long 'flagellum' or filament springs from the hilum, and by means of this filament these animalcules move about. The body, like that of all Protozoa, consists of protoplasm, and exhibits a differentiation into an outer layer or 'cuticle,' a middle or cortical layer, and a central mass. A mouth exists near the hilum, and a central particle or 'nucleus' is also contained within the body substance. Quatrefages considers Noctiluca as one of the Rhizopod Protozoa, but its general structure most nearly approaches that of a Flagellate Infusorian animalcule. Other observers have referred it to the Colenterata. See PHOSPHORESCENCE, and Pl. CXLIX.-CL. fig. 21. NODE, in astronomy, the points in which two great circles of the celestial sphere intersect each other; the straight line of intersection of the circles is called the nodal line.' When we speak of the nodes of a planet or comet, we mean the points of intersection of its orbit with the ecliptic. The point at which the orbit passes from south to north of the ecliptic is called the 'ascending node;' the other is the 'descending node.' The longitude of a node is one of the elements of an orbit; it is the angular distance of the node from the first point of Aries. NODE. When a body is vibrating, the vibratory motion is conveyed from one place to another by the action of the molecular forces of the particles on one another. Now when all the forces acting on a cer the particle consequently remains at rest, there is tain particle are at any instant in equilibrium, and said to be a node at the particle. The term is generally applied to parts which remain at rest during a considerable period of time, as those parts of the atmosphere at which silence is produced by the interference of sound vibrations, and the motionless parts of bodies of definite shape giving out musical sounds. As no vibration is quite pure in ordinary matter, but is always accompanied by others of longer or shorter periods, there can never be complete rest at any point. When the plate shown in the figure is firmly supported at its middle point in the bow, there are certain lines in it which remain a level position, and is set in vibration by means of nearly motionless during the vibration. Sand sprinkled on it will remove itself to the nodal lines, as shown in the figure. separates two parts (called 'ventral segments') of the plate which at every instant are moving in oppoEach nodal line evidently site directions. The arrangement of lines on the plate depends on the pitch of the musical sound produced by the vibration. A nodal line may be caused to start from any point by lightly touching that point with the finger. If a bell-shaped vessel is filled with water and set in vibration by means of a bow, the positions of the nodes of the bell will be indicated on the water surface. The nodes may be found on the vibrating bell when empty, by allowing places; at the ventral segments the pith-ball is a small pith-ball to hang against the sides at different violently jerked away. When the string of a sonometer (see MONOCHORD) vibrates as a whole, and therefore gives out its fundamental note, the only nodes are those at the fixed ends; when it gives out the octave of the fundamental note a node occurs in the middle of the string; when it gives out the fifth of the octave it divides into three equal vibrating parts or ventral segments, and there are two nodes in the string. If the string be touched by a feather one-third of the length from one end, and little paper rider be placed at the middle of the remaining part, this rider will be motionless when the of the octave of the fundamental note; whereas a string is set in vibration, and is giving out the fifth rider at any other place will be thrown off at once. moving in opposite directions. In the production of Parts of a string on different sides of a node are |