The valency of an element is usually expressed by dashes or Roman numerals placed on the right of its symbol, thus: H', O", B"', C I ", P", mow; but in constructing graphic formulae the symbols of the elements are written with as many lines attached to each symbol as the element which it represents has units of affinity.
The general character of these results may be obtained by a graphic construction.
The elementary use of graphic methods is qualitative rather than quantitative; i.e.
In relation to algebra, the graphic method is mainly useful in connexion with the theory of limits (ï¿½ï¿½ 58, 61) and the functional treatment of equations (ï¿½ 60).
William Gisborne's New Zealand Rulers and Statesmen,1844-1897 (London, 1897), gives many graphic portraits.
In 1583 Jan Hugen van Linschoten made a voyage to India with a Portuguese fleet, and his full and graphic descriptions of India, Africa, China and the Malay Archipelago must have been of no small use to his countrymen in their distant voyages.
- Graphic or constitutional formulae are employed to express the manner in which the constituent atoms of compounds are associated together; for example, the trioxide of sulphur is usually regarded as a compound of an atom of hexad sulphur with three atoms of dyad oxygen, and this hypothesis is illustrated by the graphic formula 0=S`O.
It is not to be supposed that there are any actual bonds of union between the atoms; graphic formulae such as these merely express the hypothesis that certain of the atoms in a compound come directly within the sphere of attraction of certain other atoms, and only indirectly within the sphere of attraction of others, - an hypothesis to which chemists are led by observing that it is often possible to separate a group of elements from a compound, and to displace it by other elements or groups of elements.
The problem of finding the sum of r terms is aided by graphic representation, which shows that the terms may be taken in pairs, working from the outside to the middle; the two cases of an odd number of terms and an even number of terms may be treated separately at first, and then combined by the ordinary method, viz.
The work is more practical than theological; and its quaint fancy, graphic and pointed style, and its fervent religious tone render it still popular with some readers.
Rational formulae of a much simpler description than these graphic formulae are generally employed.
Another consequence of the doctrine of valency was that it permitted the graphic representation of the molecule.
Carla, compiled a contoured map of France (1791), and it only needed the introduction of graduated tints between these contours to secure a graphic picture of the features of the ground.
Thiers, Histoire de la revolution francaise, gives a full and graphic account of the assignats, the causes of their depreciation, &c.; J.
See Victoria County History; Devonshire; The History of Totnes, its neighbourhood and Berry Pomeroy Castle (Totnes, 1825); William Cotton, A Graphic and Historical Sketch of the Antiquities of Totnes (London, 1858).
The graphic descriptions of Hungarian life in the middle and lower classes by Lewis Kuthy won for him temporary renown; but his style, though flowery, is careless.
"), that the graphic method leads without arithmetical reasoning to the properties of negative values.
In the graphic method of representation the sign - may be taken as denoting a reversal of direction, so that, if + 3 represents a length of 3 units measured in one direction,-3 represents a length of 3 units measured in the other direction.
The graphic method, therefore, does not give any direct assistance towards the conception of negative numbers as operators, though it is useful for interpreting negative quantities as results.
Complex numbers are conveniently treated in connexion not only with the theory of equations but also with analytical trigonometry, which suggests the graphic representation of a+b,l - by a line of length (a 2 +b 2)i drawn in a direction different from that of the line along which real numbers are represented.
The graphic description of this journey is contained in the Safarnama, which possesses a special value among books of travel, since it contains the most authentic account of the state of the Mussulman world in the middle of the 11th century.
Besides the walls and towers, and the minaret of the mosque, little remains of Mansura, of which Ibn Khaldun has left a contemporary and graphic sketch.
James Melville (1556-1614), nephew of the more celebrated reformer, Andrew Melville, who was minister of Kilrenny, has given in his Diary a graphic account of the arrival at Anstruther of a weatherbound ship of the Armada, and the tradition of the intermixture of Spanish and Fifeshire blood still prevails in the district.
The significance of relation (I) is best appreciated by considering the graphic representation of quantities of heat and energy on a work-diagram.
For a finite change it is necessary to represent the path by a series of small steps, which is the graphic equivalent of integration along the path represented by the given relation between v and 0, or p and 0.
The Elder Pliny inspired his nephew with something of his own indomitable industry; and in August 79, when the author of the Historia naturalis lost his life in the famous eruption of Vesuvius, it was the sister of the Elder and the mother of the Younger Pliny who first descried the signs of the approaching visitation, and, some twenty-seven years later, it was the Younger Pliny who wrote a graphic account of the last hours of his uncle, in a letter addressed to the historian Tacitus (vi.
The relation between the pitch of a note and the frequency of the corresponding vibrations has also been studied by graphic methods.
Aristoxenus, at the beginning of the second book of the Harmonics,, gives a graphic account of the astonishment caused by these lectures, of Plato, and of their effect on the lectures of Aristotle.
The volume which describes her conventual life is as graphic as Miss Brontes Villette, but we can only dwell on one passage of it.
Other schools are the school of naval medicine at Bordeaux with annexes at Toulon, Brest and Rochefort; schools of torpedoes and mines and of gunnery at Toulon, &c., &c. The coles dhydro graphic established at various ports are for theoretical training for the higher grades of the merchant service.
His account of this embassy in the Relatio de Legatione Constantinopolitana is perhaps the most graphic and lively piece of writing which has come down to us from the 10th century.