6o8 



NATURE 



[January 28, 19 15 



perfectly conducting tube. The problem of waves in 

 conducting^ tubes, which lias already been treated by 

 various authors, is here taken up with the purpose of 

 developing some of its solutions which offer note- 

 worthy peculiarities with respect to the velocity of the 

 corresponding waves. The waves investigated are 

 axially symmetrical and of permanent type. Their 

 velocity of transfer along the tube is a comparatively 

 simple function of the period of vibration and of the 

 "order" of waves, and it exceeds, for each of these 

 waves, the velocity of light in free space. The pecu- 

 liarities of distribution of the lines of force are illus- 

 trated by two examples with annexed drawings. The 

 paper closes with remarks concerning superpositions 

 of waves of the specified kind, more especially of 

 electromagnetic pulses.- — H. B. Keene : An telectrically- 

 heated full radiator. The essential conditions in a 

 determination of the constant of the .Stefan-Boltzmann 

 law of radiation are, either that both " emitter " and 

 ■ receiver " are full radiators, or that the amount by 

 which they fall short of full radiators is known — an 

 amount diflficult to determine with certainty. Hitherto, 

 a measurement of this constant has not been made 

 under full radiation conditions. This paper describes 

 an electrically-heated "constant temperature enclo- 

 sure " which has been constructed for temperatures 

 in the neighbourhood of iioo° C. It consists of a 

 hollow cylinder of alumina, about 8 in. in diameter, 

 closed with conical end pieces of the same material. 

 Three separate windings of platinum strip provide a 

 means of adjusting the temperature distribution 

 within the enclosure, which can be made uniform to 

 within two or three degrees. At the apex of one of 

 the cones is a circular aperture which emits radiation 

 closely approximating to full radiation. It is intended 

 to use this radiator in conjunction with a full receiver, 

 described in an earlier paper, in order to determine 

 the value of the radiation constant under "black- 

 body " conditions. 



Geological Society, January 6. — Dr. A. Smith Wood- 

 ward, president, in the chair. — C. I. Gardiner : The 

 Silurian inlier of Usk (Monmouthshire). The Usk 

 inlier lies a few miles north of Newport (Mon.). 

 Between the coalfields of South Wales and the Forest 

 of Dean the Old Red Sandstone is bent into an anti- 

 cline, the axis of which runs very nearly north and 

 south. This has been denuded away to the west of 

 Usk, and Silurian beds have been exposed, the rocks 

 seen being of Ludlow and W'enlock age. In the 

 southern part of the inlier the Silurian rocks are 

 arranged in two anticlinal folds, the axes of which 

 run nearly north and south and dip southwards. 

 These folds are separated by a fault. The Old Red 

 Sandstone is believed to rest unconformably on the 

 Ludlow Beds along much of the margin of the Coed-y- 

 paen anticline, and beneath the Ludlow beds, which 

 are about 1300 ft. thick, come 35 to 40 ft. of a 

 Wenlock Limestone, which covers Wenlock Shales : 

 of these latter some 850 ft. are seen. At their base the 

 Ludlow Beds seem to pass conformably down into the 

 Wenlock Beds, and the Wenlock Limestone is prob- 

 ably not at the summit of the Wenlock Shales. The 

 Wenlock Limestone occurs either in irregular layers 

 separated by sandy shales, or in massive beds largely 

 made up of crinoid fragments. — S. R. Haselliurst : 

 some observations on cone-in-cone structure and their 

 relation to its origin. In a brief review our state of 

 knowledge is summarised, and the deductions of other 

 investigators are analysed. The author critically 

 examines the accepted hypothesis that cone-in-cone 

 structure is something essentially due to crystallisa- 

 tion. He describes the results of some high-pressure 

 mimetic experiments. These experiments were de- 

 signed to produce this structure, and reveal what the 



NO. 2361, VOL. 94I 



author believes to be many new points on the origin 

 of concretions and cone-in-cone in particular. 'Ihe 

 experiments are new, inasmuch as the media used, 

 namely : brittle, semi-plastic, and plastic, are enclosed 

 in tunics of varied design, and then subjected either 

 to a high uniform hydrostatic pressure or to a direct 

 thrust. The author concludes from the evidence : — (i) 

 That cone-in-cone is not due to crystallisation, but is a 

 mechanically produced structure due to great and 

 localised pressure; (2) that it is closely allied to the 

 phenomenon known as pressure solution ; (3) that 

 cone-in-cone structure is closely associated with other 

 rock-structures which are mutually indicative the one 

 of the other, and also of their mode of origin. 



Edinburgh. 

 Royal Society, December 21, 19 14. — Sir Thomas 

 Fraser, vice-president, in the chair.^ — Sir Thomas 

 Fraser : The poisoned arrows of the Abors and Mishmis 

 of north-east India, and the composition and action of 

 their poisons. A large collection of arrows, bows, 

 and quivers had been, received from time to time 

 from medical and military officers of the Indian Army, 

 and it was soon apparent that different poisons were 

 used in different groups. In one group, chiefly used 

 by the Mishmis, the action of the poison suggested 

 aconite as the active agent. In another group, used 

 by the Abors, the arrows yielded, on extraction with 

 ether, an oil with the physical characters of the oil 

 of Croton tiglium. This oil could not produce death 

 in warm-blooded animals, but was lethal to frogs. 

 The poison on the aconite arrows varied greatly in 

 power. If the whole of the poison of one arrow 

 were absorbed, a most improbable possibility, the 

 most active arrows carried enough to kill three men. 

 — J. Herbert Paul : Regeneration of the legs of 

 Decapods from the preformed breaking planes. vVhen 

 a lobster, hermit crab, or shore crab loses a limb, 

 a small limb bud forms as the first stage in the pro- 

 cess of regeneration. When the animal moults, this 

 bud rapidly expands to the size of the true complete 

 limb, becomes covered with a hard calcified layer like 

 the rest of the integument, and gains full functional 

 power in a few days. The paper contained a detailed 

 account of the manner in which the various stages 

 of regeneration 'were effected. When the old limb is 

 lost the valvular action of the diaphragm at the 

 breaking plane prevents haemorrhage ; and in the 

 regenerative process a new diaphragm is the first 

 structure laid down. — Prof. Alex. Smith and R. H. 

 Lombard •. The degrees of dissociation in the saturated 

 vapours of the ammonium haloids. The paper was 

 concerned with the densities and degrees of dissocia- 

 tion of the chloride, bromide, and iodide of ammo- 

 nium. In the chloride the degree of dissociation was 

 nearly constant within the range of temperatures 

 from 280° to 330° ; in the bromide it reached a maxi- 

 mum about 320°, and diminished steadily up to 388° ; 

 and in the iodide it was practically zero. There was 

 evidence in the last case of association above 340°. 

 The results for the bromide showed that, about 320°, 

 the heat of dissociation was positive. This seemed 

 to be the first observation of a positive, heat of dis- 

 sociation in the gaseous state. 



Paris. 

 Academy of Sciences, January 11. — M. Ed. Perrier in 

 the chair. — L. Lecornu : The deformation of cylin- 

 drical tubes. — Andre Blondel : Calculation of the 

 range of optical projectors both on land and sea. A 

 formula is deduced in which certain constants can 

 onlv be. determined experimentally, and suggestions 

 are made as to the best means of determinin^j these 

 constants. — Edouard Meckel : Sohvnini Caldasii 



