440 



NATURt 



[December 17, 1914 



SOCIETIES AND ACADEMIES. 

 London. 

 . Physical Society, November 27. — Dr. A. Russell, vice- 

 president, in the chair. — A. F. Hallimond : Note on the 

 conduction of electricity at j)oint contacts. The 

 " characteristic " or volt-ampere curves given by 

 various "point" contacts when the voltage is slowly 

 varied are dealt with. The curves were plotted by 

 means of a form of rocking mirror galvanometer, 

 which projected the characteristic as the path of a 

 spot of light on the screen, the co-ordinates being 

 respectively proportional to the current and voltage. 

 The first part describes the behaviour of a typical 

 contact, zincite-tellurium. The second part describes 

 the results obtained on examining the characteristics 

 for the forty-five contacts possible between ten chosen 

 substances. The results in all cases are similar to 

 those given by zincite-tellurium. No line* could be 

 drawn separating " metallic " contacts from those in 

 which one or both conductors were "crystals." In 

 the third part the conclusion is drawn that in a con- 

 tact yielding the unilateral (high resistance) curve, the 

 resistance lies within the surface of the member 

 standing higher in the series. — T. Barratt : Thermal 

 conductivity of badly conducting solids. The thermal 

 conductivities of typical solids of low thermal con- 

 ductivity have been determined by the method em- 

 ployed by the author for pure metals and alloys. The 

 substances tested include electrical insulators, such as 

 glass, fused silica, and ebonite, various kinds of wood, 

 and some partial conductors of electricity — viz., carbon 

 and graphite. It has been shown that the thermal 

 conductivity k is given by 



Ji: = 



H2 coth2 a/ 



or, where "2" is sufficiently great. 



k = 



pghN'^" 



Where H is the heat given to one end of the specimen, 

 of length Z, perimeter p, and cross-sectional area q ; 

 V is the difference of temperature of the "hot" end 

 of the specimen and the enclosure ; h is the heat lost 

 from I sq. cm. of the surface per second when its 

 temperature is 1° C. above that of the enclosure; and 



V qk 



In nearly every case the simpler form of the equation 

 could be used. For the first time in the measurement 

 of thermal conductivity a direct comparison of this 

 quantity in the case of a non-metal has been made 

 with that of a metal — viz., bismuth — the conductivity 

 of which is of the same order of magnitude as those of 

 some of the non-metals. The results agree well with 

 those obtained by Prof. Lees's "disc" method in 

 cases where direct comparison is available. 



Geological Society, December 2. — Dr. A. Smith Wood- 

 ward, president, in the chair. — Prof. T. McKenny 

 Huglies : The age and character of the Shippea Hiil 

 man. A description of the skeleton, and of the cir- 

 cumstances in which it was found, is given. The 

 mode of formation of the deposit in which the remains 

 occurred is discussed. The Pleistocene deposits of the 

 Fenland were, it is considered, laid down in a de- 

 pressed river-basin behind a breached seaward barrier. 

 Gravels of the age of Elephas antiquiis and Rhino- 

 ceros nierckii, as well as gravels of the age of E. 

 primigenius and R. tichorhinus , occur within the Fen- 

 land ; but they are distinguishable from the gravels 



NO, 2355, VOL. 94] 



which are sometimes associated with the peat and 

 clay, and pass under them. The fauna also of the 

 peat- and clay-deposits is quite different. In an 

 embayed part of the Fen, close behind the island 

 known as Shippea Hill, the skeleton was found in 

 the peat, a few inches above the clay which is con- 

 sidered to be the equivalent of this Littleport Cockle 

 Bed. When first dug out the skull was in fragments, 

 and the calotte, with its prominent brow-ridges, sug- 

 gested to many a greater affinity to the Neanderthal 

 type, and a greater antiquity than appeared probable 

 when the rest of the cranium was added to it. — C. 

 Dawson and Dr. A. Smith Woodward : A bone imple- 

 ment from Piltdown (Sussex). Excavations have been 

 continued in the Piltdown gravel round the edge of the 

 area previously explored. Rolled fragments of highly 

 mineralised teeth of Rhinoceros and Mastodon were 

 again found, but no human remains were met with. 

 The most important discovery was a large bone 

 implement now described. This specimen was found 

 in dark vegetable soil beneath the hedge which bounds 

 the gravel-pit, not far from the spoil-heap whence the 

 right parietal bone of the Piltdown skull was obtained 

 two years ago. On being washed away the soil left 

 no stain on the bone, which was covered with firmly 

 adherent yellow clay, closely similar to that of the 

 flint-bearing layer at the bottom of the gravel. The 

 bone itself is highly mineralised, and agrees exactly 

 in appearance with some small fragments of bone 

 discovered actually in place in the clay just mentioned. 

 There can be no doubt that the implement was found 

 by workmen digging gravel from the adjacent hole, 

 and thrown away with other useless debris. It is a 

 stout and nearly straight narrow flake of bone, 41 cm. 

 long, and varying from 9 to 10 cm. in width, with 

 the thicker end artificially pointed, the thinner end 

 artificially rounded. It appears to be a longitudinal 

 strip flaked from a limb-bone by a blow at the thicker 

 end, in the same way as flint implements were flaked 

 from their original cores. Direct comparison suggests 

 that it was taken from a Proboscidean femur as large 

 as that of Elephas meridionalis. In microscopic 

 structure it agrees with Proboscidean bone. The ends 

 of the implement are shaped by cutting, and bear 

 no marks of grinding or rubbing. Most of the cut 

 facettes are small, and many suggest that the}- were 

 made by a primitive tool, presumably a flint. The 

 rounded end seems to have been trimmed for comfort- 

 able handling. The thick pointed (or, rather, keeled) 

 end shows signs of battering or scratching by use. 

 Just above the pointed end one lateral edge of the 

 bone is marked by a large smooth groove running 

 across from the inner to the outer face of the bone. 

 It seems to have been originally a perforation from 

 which the outer wall has been accidentally broken 

 away. Within it on the inner face is the beginning of 

 a second similar perforation, as if an attempt had 

 been made to repair the damage. The conclusion is 

 that the implement is unique, and no explanation of 

 its specific use is given. 



Linnean Society, December 3. — Prof. E. B. Poulton, 

 president, in the chair. — R. C. McLean : An ecological 

 journey in South America. — C. West and Hisayoshi 

 Takeda': Isoetes japonica, A. Br. I. japonica, A. Br., 

 which has a fairly wide distribution in Japan, is the 

 largest known species of this genus ; according to 

 Makino, a diameter of 8 cm. is attained by the caudex 

 of very large specimens. The tri-lobed caudex con- 

 sists of two distinct structures, viz., siem and rhizo- 

 phore, to which the leaves and roots are respectively 

 attached. But owing to the stunted growth of the 

 plant, all external morphological differentiation be- 

 tween the two organs has been completely lost. 



