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Ann. Chem. Pharm., Suppl. 6+7. - Leipzig und Heidelberg, C.F. Winter'sche Verlagsbuchhandlung, 1868, 8°, (4), 390 pp., 3 Taf.; 1870, 8°, (4), 380 pp., 3 gefalt. Tafeln, geprägter Leinenband d.Zt; Rücken erneuert, feines Exemplar. First appearance in print of this groundbreaking, classic paper in which Lothar Meyer (1830-1890) first fully expressed his ideas of the relationships between the atomic weight of the elements and their properties. - The Periodic Law. "This law, which was discovered independently and almost at the same time*, in 1868-9, by the German chemist, Lothar Meyer and by the Russian chemist, Mendeleeff, may be stated in the words: The properties of the elements are a periodic function of (or vary in a periodic manner with) the atomic weight." "On arranging the elements in the order of their atomic weights, as then known, and keeping in view the possibility of undiscovered elements, a remarkable recurrence of properties was observed. This periodicity was rendered very clear by Lothar Meyer in the case of physical properties, by plotting the values of the physical property, e.g., the atomic volume (volume of 1 gram multiplied by the atomic weight), against the atomic weights of the elements. On joining together the different points, the curve shown in Fig. 1 (see the plate) was obtained. The periodic variation of the atomic volume is thus represented very clearly; and it will be observed that elements of similar chemical properties, e.g., the alkali metals, occur at corresponding points on the different parts of the curve." Not only was periodicity observed in the case of physical properties but it was equally evident in respect of the general chemical properties and of the valency. Thus, when the elements were arranged in order of ascending atomic weights and in accordance with the valence, Lothar Meyer and Mendeléeff showed that they fell into a number of groups or families of related elements, or elements having analogous properties. In this way a natural classification of the elements, depending on the relation between the chemical properties of the elements and their atomic weights, was obtained. This is the so-called periodic classification of the elements." "If the periodic law had important practical applications, the recognition of its essential validity also greatly stimulated speculation and investigation into the genesis of the elements, for as Lord Salisbury said: "The discovery of co-ordinate families dimly points to some identical origin, without suggesting the method of their genesis or the nature of their common parentage." On these questions much light was thrown by the experimental investigations of the closing decades of the nineteenth century and the opening decades of the twentieth century, and out of these there developed the theory of the electronic constitution of matter by means of which the periodic law receives interpretation." Alexander Findlay, A Hundred Years in Chemistry. 2nd. ed. (1848), pp.49-54 *) "The question of priority in the discovery of the periodic law gave rise to some controversy. The first clear statement of the periodic law seems to have been published by Mendeléeff in 1869, but in 1868 a classification of the elements, similar to that published by Mendeléeff in 1872, had been drawn up, although not published, by Lothar Meyer who, even in 1864, had published tables of the elements which may be regarded as forerunners of the periodic classification. Honours may be regarded as even, and were recognized as such by the Royal Society which awarded the Davy Medal to both scientists in 1882. (See G. Rudorf, The Periodic System.)". Seller Inventory # 52370
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