6o 



NA TURE 



[July 14, 1923 



crystals in round bars. In each case the two fractured 

 halves are shown, one placed with the broad and the 

 other with the narrow side facing the camera. 



A word must be said about the crystallography of 

 aluminium. Hull was the first to investigate the 

 structure of aluminium crystals in a finely crystalline 

 aggregate by X-ray analysis, and he concluded that the 

 pattern thus obtained corresponds to a face-centred 

 cubic lattice, i.e, the grouping of the atoms is such 

 that there is one at each corner of the cube, and one 

 in the centre of each face, making a total of fourteen 

 in all. This corresponds, as Colonel Belaiew has 

 recently pointed out, to an octahedron situated within 

 a cube. Sir William Bragg and Dr. Muller have 

 kindly examined our single crystals, and find that they 

 conform to the same pattern. They belong, therefore, 

 to the cubic system, and must have properties con- 

 sistent with those of that group which possesses the 

 highest degree of symmetry both external and internal. 

 Investigations of the crystals in this system indicate 

 that as regards certain properties they are isotropic, 

 while as regards others they are anisotropic. In 

 the former category come the properties of conducting 

 light, heat, electricity, and expansion. In the latter 

 are grouped elasticity, cohesion, and conduction of 

 sound. In such cases, however, the properties are 

 closely related to the symmetry, since the maximum 

 and minimum values have been found to coincide with 

 the axes of symmetry. 



Accordingly, the variations in the tensile properties 

 of the testpieces which have been described are due 

 to differences of cohesion in different planes which 

 do not all contain the same number of atoms. Although 

 the single crystals obtained in the sheet and bars 

 were formed in the same shaped testpieces in both 

 categories, it was obvious that their original orientation 



relative to the axis of the testpiece varied considerably. 

 Indeed, it may not have been precisely the same in 

 any two of the cases tested. The shape of the test- 

 piece alters when stress is applied, since slip and 

 deformation take place only on certain planes, and the 

 changes in shape observed correspond to the attempt 

 of the crystal to accommodate itself to the stress. Such 

 changes were much greater in some tests than in others. 

 It is not possible within the limits of this article 

 to discuss the two questions, (i) why abnormally 

 large crystals form on heating after a small deformation, 

 and gradually decrease in size as the deformation 

 increases ; and (2), to take the extreme case, why, 

 after* a particular degree of deformation, it is possible 

 to form a single crystal from an aggregate of several 

 millions. Those interested in the matter may be 

 referred to the author's original publications with 

 Miss Elam.i It may, however, be stated that the 

 conditions for the production of a single cr\'Stal in 

 a testpiece consisting of the usual aggregate of small 

 crystals are considered by us to be, that even,- cr}'stal 

 in the complex must be strained a certain amount, 

 and that one of them is strained rather more than the 

 rest. This particular crystal may be regarded as 

 being in the condition of critical strain, and ultimately 

 all the other crystals align themselves upon it after 

 sufficient heating. When this condition is realised, 

 the testpiece consists of a single crystal. We have 

 taken up the experimental investigation of the deforma- 

 tion of the testpiece by X-ray analysis, and are hopinu 

 that the result of this will show what it is that happen.^ 

 when a testpiece is strained to the critical amount 

 and subsequently heated. 



• Journal of the Institute of Metals, No. 2, 1920, pp. 83-131. Proceedings 

 of the Royal Society, V. looa, pp. 329-353. Journal of the Iron and 

 Steel Institute, No. i, 1923. 



The Royal Asiatic Society. 



By F. E. Pargiter. 



THE Royal Asiatic Society of Great Britain and 

 Ireland was founded in London on March 15, 

 1823, by the distinguished Sanskrit scholar, Henry 

 Thomas Colebrooke, supported by others interested 

 in Oriental matters, to investigate (as he announced) 

 the history, civil polity, institutions, customs, languages, 

 literature, and science, ancient and modern, of all 

 countries in Asia. This removed the reproach that, 

 while similar societies had been formed at Calcutta, 

 Bombay, Madras, Paris, and elsewhere, Great Britain 

 had done nothing. The charter was granted on 

 August II, 1824, and under it the Society is governed 

 by a council of twenty-five members, including the 

 president, director, vice-presidents, and other officers, 

 elected annually at general meetings. 



The Society was well supported by the East India 

 Company and many eminent men, and prospered and 

 developed its activities. It appointed a " Committee 

 of Correspondence," which embarked on far-spread 

 measures to receive and communicate information 

 about Asiatic matters. From the copious donations 

 that it received it began a hbrary and a museum. 

 To utilise the Oriental MSS. collected in English 

 libraries it established the " Oriental Translation ' 



NO. 2802, VOL. 112] 



Committee and Fund " in 1828, to publish translations 

 of approved works in Oriental languages, and this 

 was liberally supported, and published thirty volumes 

 in the next four years. The scheme included measures 

 to benefit Asia and Europe materially ; hence, when 

 trade with India and China w^as thrown open in 

 1833-34, the Society formed a " Committee of Agri- 

 culture and Commerce " in 1836, and this collected 

 valuable information about coffee, sugar, opium, and 

 other important commercial products and their 

 improvement. The Society published three quarto 

 volumes of " Transactions," containing papers read 

 before it, in 1827, 1830, and 1833, and began an 

 annual " Journal " in 8vo form in 1834. 



The early enthusiasm, however, gradually declined ; 

 the membership fell and the financial position caused 

 anxiety. Then came the time of the Cuneiform 

 discoveries by Major (afterwards Sir) Henry Rawlinson, 

 who found the great Behistun and other inscriptions 

 in Persia, eclipsing those reported by earlier travellers. 

 He communicated them to the Society in 1838, solved 

 the problem of their decipherment in 1844, and 

 announced his results in 1846. These were received 

 by the public with much incredulity, but the Society 



