April 'i, 1 886] 



NA TURE 



549 



buting in any way to the advance of philology. — Hypothetical 

 suggestions as to the origin of right-handedness or left- 

 handedne s, by M. Dareste. The author believes that we 

 must seek in embryonic relations for the preponderance of the 

 right hand over the left, in which he sees a possible result of the 

 position generally maintained by the foetus in regard to the 

 vitellus, in which one side of the body enjoys greater freedom 

 for development than the opposite one. Di. Dareste wishes to 

 verify, by the observation of others, his hypothesis that left- 

 handedness is present in those who suffer from inversi n of the 

 viscera (heterotaxy), which would seem to be unquestionably due 

 to malposition in the fcetal state. — M. Sebillot has presented to 

 the Society a comprehensive formula of questions relating to the 

 appearance, character, and various other phenomena of the sea, 

 together with the popular legends and superstitions connected 

 with it by different races. These he wishes to see incorporated 

 with the Society's authorised directions for travellers. — Mote on 

 May celebrations in the Gironde, by M. Daleau. — Discussion on 

 the a-sumed Quaternary jaw found at Chalons-sur-Marne, and 

 forming part of M. Nicaise's collection. M. Topinard, who 

 gave the result of his own measurements, considers that the 

 differences between this jaw and the one found at Naulette 

 prove the co-existence, in primaeval ages, of different human 

 types. The Naulette jaw he regards as unique of its 

 kind, differing as it does from the thousand and upwards 

 of inferior ma.xillac which he had examined with special 

 reference to this question. — On the difficulties of distin- 

 guishing between genuine prehistoric trepanning and recently 

 effected injuries of the crania, either through accident in 

 the process of exhumation, or for purposes of deception, by 

 M. Manouvrier. — On the best means of measuring the cranial 

 capacity, by M. de Jouvenrel. — On Broca's method of deter- 

 mining cranial cubage, as exemplified by means of a bronze 

 test-cranium, by M. Topinard. — On an archaeological explora- 

 tion on the Island of Teviec, near Quiberon, by M. Gaillard. 

 The similarity of the dolmens, shells, and bones with those on 

 the neighbouring mainland, and the numbers and character of 

 the silex and bone fragments found on the island, lead the 

 w riter to believe tliat a separation from the continent has been 

 effected since prehistoric ages. — On the Dutch dwarf known as 

 Princess Pauline, by M. Mortillet. — On curious methods of 

 conducting barter in parts of Asia and Africa, by M. Hove- 

 lacque. In tracing the history of the development of the pro- 

 cess of bartering silently and from a distance, which still pre- 

 vails between tribes or castes who refuse to meet or be seen by 

 each other, the author draws attention to notices by Herodotus 

 which prove the existence of the same customs among the people 

 of Libya. — On the. existence of wars in primaeval times, by Dr. 

 Hoffman, of Washington. — On the finds of a cave near Ojcow, 

 by M. Zaborowski. Numerous fragments of the bones of the 

 mamuioth, rhinoceros, hytena, and cave-bear were found inter- 

 mixed with those of the ox, borse, hare, &c., together with flint 

 knives, bone implements, cS:c. — On the brain of an insane woman, 

 by M. Rey. — On a case of microcephalism, by M. Letourneau. — 

 On a gibbon-fcetus and its placenta, by iM. Deniker. — On ideas 

 and memory, by M. Fauville. In this elaborate treatise the 

 author considers memory as the result of special manifestations 

 of the impressionability of the sensient cellules of the brain, 

 while ideas are defined as the consequences of sensations. — On 

 the common origin of Malays and Dravidians, by M. O. Beau- 

 regard. In this sequel to his former paper on the subject of the 

 Malayan races the author begins with their language, which 

 may be traced from the Moluccas as far west as Easter Island, 

 many words in use among the inhabitants of the various island- 

 groups that lie between these remote limits being absolutely the 

 same. This paper is an exhaustive compendium of what has 

 been written by other authors, chiefly Knglishmen, on the lan- 

 guage and legendary literature, the political and social constitu- 

 tion, and the religion and laws of the Malayan and Dravidian 

 races, with special reference to those settled in Ceylon. 



SOCIETIES AND ACADEMIES 



London 

 Royal Society, February II. — "The Electrical Phenomena 

 accompanying the Process of Secretion in the Salivary Glaiids 

 of the Dog and Cat." By W. Maddock Bayliss, B.-Sc, and 

 J. Rose Bradford, B. Sc, Senior Demonstrator of Anatomy in 

 University College, London (from the Physiological Laboratory 

 of University College). Communicated by E. A. Schafer, F. R. S. 



March ii. — "The Influence of Stress and Strain on the 

 Physical Properties of Matter. Part I. Elasticity (continued). 

 The Internal Friction of Metals." By Herbert Tomlinson, B. A. 

 Communicated by Prof. W. Grylls Adams, M.A., F. R.S. 



An abstract of a paper on this subject has been already pub- 

 lished (Proc. Roy. Soc, vol. xxxviii. p. 42), but the paper itself 

 was withdrawn for the purpose of revision. The fresh experi- 

 ments which have been for this purpose instituted during the 

 last year, besides confirming the results of the older ones, as 

 far as the latter have been published, have furnished, more or 

 less in addition, the following facts relating to the internal 

 molecular friction of metals : — 



The proportionate diminution of amplitude is independent of 

 the amplitude, provided the deformations produced do not ex- 

 ceed a certain limit. This limit varies with the nature of the 

 metal, and is for nickel very low. 



The logarithmic decrement of amplitude increases with the 

 length of the vibration-period, but in a less proportion than the 

 latter, and in a diminishing ratio. The amount of increase of 

 the logarithmic decrement, attending on a given increase through 

 a given range of the vibration-period, varies with the nature of 

 the metal, and with those metals which possess comparatively 

 small internal friction becomes almost insensible. It follows as 

 a consequence that the internal friction of metals differs from 

 the viscosity of fluids, for in cases of damping by the latter the 

 logarithmic decrement is inversely as the length of the vibration- 

 period. 



Permanent molecular strain resulting from loading not carried 

 to a sufficient extent to produce sensible permanent extension, 

 diminishes the internal friction, and increases the torsional 

 elasticity. 



Considerable permanent longitudinal extension and permanent 

 torsion produce increase of internal friction and diminution of 

 torsional elasticity. The effect of torsion is much greater than 

 that of extension, and the increase of internal friction is much 

 greater than the decrease of torsional elasticity. As a conse- 

 quence, wire-drawing, where we have permanent extension and 

 torsion combined, sometimes increases enormously the internal 

 friction ; in fact, in the case of six different metals it was found 

 that, by careful annealing, the internal friction was decreased 

 from one-half to one-thiiiiiih of the original amount of friction 

 of the metals in the hard drawn condition. 



The internal friction of a metal wire, whether in the hard- 

 drawn or annealed condition, is temporarily decreased, and the 

 torsicmal elasticity is temporarily increased by loading not 

 carried beyond a certain limit ; beyond this limit both the friction 

 and the elasticity become independent of the load. 



The "fatigue of elasticity," discovered by Sir William Thom- 

 son in metal wires when vibrating torsionally, is not felt, 

 provided the deformations produced do not exceed a certain 

 limit, depending up m the nature of the metal. The above- 

 mentioned limit is extraordinarily low for nickel, so low, indeed, 

 that it is difficult to avoid "elastic fatigue " with this metal. 

 This last consideration, and others founded on the results of 

 experiments on the effects of stress on the physical properties of 

 nickel, tend to .show that the molecules of this metal are com- 

 paratively easily rotated about their axes. 



The author agrees with Prof. G. Wiedemann, that the loss of 

 energy due to internal friction in a torsionally vibrating wire Is 

 mainly due to the to-and-fro rotation of the molecules about 

 their axes ; any cause, therefore, which increases the iTiolecular 

 rotatory elasticity diminishes the internal friction, and con- 

 versely. 



The molecules of a metal tend to creep into such positions as 

 will ensure a maximum molecular rotatory elasticity, and they 

 can be assisted in doing so by agitations effected either by 

 thermal or mechanical agency ; hence — 



Rest after suspension, aided by oscillations at intervals, 

 diminishes the internal friction of a wire which has been 

 recently suspended, or which after a long suspension has been 

 subjected to considerable molecular agitation by either me- 

 chanical or thermal agency. 



On the contrary, when a maximum molecular rotatory elasti- 

 city has been reached, molecular agitation, if carried beyond a 

 certain limit, diminishes the elasticity ; hence the results of 

 "fatigue of elasticity ; " and hence — 



Mechanical shocks and rapid fluctuations of temperature 

 beyond certain limits may considerably increase the internal 

 friction, and, though to a much less extent, diminish the 

 torsional elasticity. 



