June 9, 1881] 



NATURE 



135 



Sitztmgsbcrichte dcr physikalisch-iiKdicinischen Societal zti 

 Erlangcn, November, 1S79, to Aujust, 1880. — On general theta- 

 functions, by M. Noether. — Preparations of human ear-bones 

 for lecture pur[ioses, by L. Gerlach. — On the occurrence of two 

 ampullaj in the outer (horizontal) arch of the bony labyrinth, by 

 the same. — On the excretion of hippuric and benzoic acid during 

 fever, by T. Weyl and B. v. Anrep. — On section-systems of 

 algebraic curves, by J. Bacharach. — On the work-product of 

 muscles, by J. Rosenthal. — On dichroitic fluorescence on platino- 

 cyanides of magnesium ; experimental proof of the perpendicu- 

 larity of the light-vibrations to the plane of polarisation, by E. 

 Lommel. — On the phenomena, in polarised light, of a plate of 

 platinocyanide of magnesium cut at right angles to the optic 

 axis, by the same. — On an artificial lung-cavity preparation, by 

 F. Penzildt.— On gluten, by T. -Weyl and H. Bischoff — 

 On carbonic oxide haemoglobin, by T. Weyl and B. v. Anrep. 

 — On vagus-stimulation, by J. Rosenthal — On unipolar nerve- 

 stimulation and false nerve-stimulation by derived currents, 

 by the same. — On fluorescence, by E. Lommel. — On the in- 

 variant representation of algebraic functions, by M. Noether. — 

 On the para'iiti-m of Elaphomyces grantilatus, by M. Reess. — 

 On poisoning with morels, by E. Bostroem. — On adventive for- 

 mations, by A. Hansen. — Does the ground-air contain ammonia? 

 liy L. Rinck. — On oxygen determination, by F. Zeitler. — Con- 

 tributions to pathological anatomy, by E. Bostroem. 



SOCIETIES AND ACADEMIES 

 London 



Geological Society, May 25. — R. Etheridge, F.R.S., pre- 

 sident, in the chair. — Rev. Tom Bullock Harden), M.A., 

 LL.M., was elected a Fellow of the .Society. — The following 

 communications were read ; — On the discovery of some remains 

 of plants at the base of the Denbighshire grits, near Corwen, 

 North Wales, by Henry Hicks, M.D., F.G. S. ; with an appen- 

 dix by R. Etheridge, F.R.S., Pres. Geol. Soc. Traces of these 

 fossils were first observed in 1875 by the author in Pen-y-glog 

 quarry, about two miles east of Corwen. Further research has 

 resulied in the discovery of more satisfactory specimens, which 

 have been examined by Messrs. Carru'hers, Etheridge, and E. 

 T. Newton. Among them are spherical bodies resembling the 

 Pachytheca of Sir J. D. Hooker, from the bone-bed of the 

 Ludlow series, supposed to be Lycopodiaceous spore-cases ; also 

 numer lus minute bodies stated by Mr. Carruthers to be united 

 in threes, and to agree with the forms of the microspores of 

 Lycopodiacene, both recent and fossil ; and some fragments, 

 which may belong to these plants, and others, probably belong- 

 ing to plants described by Dr. Dawson from the Devonian ot 

 Canada under the name of Psilophyton. The above testify to 

 the existence of a very rich land-flora at the time. Mixed up 

 with the e however are numerous carbonaceous fragments of a 

 plant descriied also by Dr. Dawson from the Devonian of 

 Canada, which he referred to the Coniferoe, but which i-;, accord- 

 ing to Mr. Carruthers, an anomalous form of Alga. The former 

 called it ProtolaxiU-s ; the latter renamed it A'ematophycut. 

 Numerous microscopical sections, showing the beautilul structure 

 of this interesting plant from the specimens found at Pen y-glog, 

 have been examined by Mr. Etheridge and Mr. Newton, and 

 their conclusions agree with those of Mr. Carruthers. The 

 evidence seems to show that at this mid -Silurian period the 

 immediate area where the plants are now discovered must have 

 been under water, and that the mixture of marine and dry-land 

 plants took place in consequence of floods on rapid marine 

 denudation. The author indicated that the land-areas mu-t have 

 been to the south and west, chiefly islands, suiTounded by a 

 moderately deep sea, in which Graptolites occurred in abundance. 

 The position of these beds may be staled to be about 2000 feet 

 below the true Wenlock series, and about the horizc^n of the 

 Upper Llandovery rocks. — Notes on a mammalian jaw from the 

 Purbeck beds at Swanage, Dorset, by Edgar Willett. Commu- 

 nicated by the President. 



Physical Society, May 28.— Prof. Fuller, vice-president, in 

 the chair. — Mr. C. Woodward exhibited apparatus for illus- 

 trating w ve-motions to a class. This consisted of a number of 

 glass panes of equal size mounted on stands so that they could 

 be ranged in a line or in rank and file. Patches of blue paper 

 were attached to them to represent the moving particle of the 

 wave, the |io-itions being determined by a dia.;rammatic card 

 which fi ted each pane. A machine for showing Fresnel's con- 

 ception of polarised light consisted of two axles fitted with a 



number of cranks which supported a roof of rafters bearing at 

 their ridges a number of beads to guide the eye in tracing the 

 wave-motion. By turning the axles the cranks shifted the frame 

 of rafters, and the beads di-played the wave-motion, which was 

 vertical, elliptical, or circular according to the adjustment. — 

 Prof. G. Forbes explained the experiments made by him and 

 Dr. Young to determine the velocity of light. The method 

 employed was that of Fizeau, but instead of having one distant 

 reflector and observing the total eclipse of the reflected ray by a 

 tooth of the revolving wheel, two reflectors, one a quarter of a mile 

 behind the other, were used, and two rays, which were observed 

 when of equal brightness. This method was found more 

 accurate than Fizeau's own plan, and gave curves of bright- 

 ness. The speeds of the toothed wheel were adjusted until the 

 two rays aiipeared of equal brightness. The general result was 

 that the velocity of the light of an electric lamp is 187,200 

 miles per .second. Cornu found the light of a petroleum lamp to 

 be 186,700 miles per .second, and Michaelson that of the sun to 

 be 186,500 miles per second. The higher number of Prof. 

 Forbes is probably due to the bluer': light of electricity, for 

 further experiments made with coloured lights and the spectrum 

 seemed to prove that blue light travels probably over i per 

 cent, faster than red light. The experiments were made at 

 Wemyss Bay, in Scotland. Mr. Spottiswoode, P. R.S., said 

 he had followed Prof. Forbes with interest, and these 

 results appeared to modify our ideas of the luminiferous 

 ether. Lord Rayleigh inquired why it was that Jupiter's 

 satellites .showed no difference in tint in emerging from 

 eclipse if red and blue rays travelled with unequal velocities ? 

 Prof. Forbes believed it due to the gradual character of the 

 emergence if the satellites from behind their primary. According 

 to the new theory variable stars should however seem bluish with 

 an increa-e of their light. Prof. G. C. Foster pointed out that 

 dispersion of the light in the air would rather have had the effect 

 of retarding the blue rays. Mr. Hall of Baltimore, U.S., then 

 exhibited the experiment in which a current of electricity flowing 

 longitudinally along a thi-i foil of metal is caused to yield a trans- 

 verse or lateral current by inserting the foil between the poles of a 

 magnet. The lateral current is observed on a sensitive galvano- 

 meter, and care is taken in the first place to find points of con- 

 nection with the foil, which yield no current before the magnet 

 is applied. The results were that if iron is called -I- the series 

 is iron + , silver - , gold - , platinum - , tin - . Curiously, 

 nickel, though a magnetic metal like iron, is - ; but on inquiry 

 by Prof. Chandler Roberts it proved that the nickel employed 

 was perhaps impure. Cobalt ranges between iron and silver, 

 and is + , like iron. Prof. Perry suggested that the displacement 

 and huddling of the lines of flow of the current by the magnet 

 might cause the current ; but Mr. Hall said that an experiment 

 had been tried to test that, and went to prove that it was not due 

 to crowding of these lines. — The Secretary read a pajier by Prof. 

 J. H. Poynting on the change of bodies from the solid to the 

 liquid states. There are two types of change exem]>lified by ice- 

 water and by sealing-wax : in the one a surface melting at the 

 same temperature, in the other a softening of mass and heating. 

 The first was thought by Prof. Forbes to be a limiting case of 

 the .second type, but the author gives reasons for suppo-ing that 

 it is rather an exchange phenomenon analogous to what takes 

 place when water evaporates, and the melting-point is reached 

 when the number of molecules passing from the ice to the water 

 is equal to the number passing from the water to the ice. The 

 sealing-wax type is analogous to the change of state in a liquid - 

 gas above its critical point, where it changes gradually from a 

 rather liquid to a certainly gaseous state. 



Anthropological Institute, May 10. — Major General A. 

 Pitt-Rivers, F.R.S., president, in the chair. — Mr. Hyde Clarke 

 exhibited a collection of stone implements collected by Mr. 

 Papadipoulo Keramenes of Smyrna. — Lieut. -Col. R. G. Wood- 

 thorpe, K.E., read a paper on the wild tribes of the Naga Hills. 

 — Prof. G. Dancer Thane read a paper on some Naga skulls. 



May 24.— Major-General A. Pitt-Rivers, F.R.S., president, 

 in the chair. — Mr. E. H. Man read a paper on the arts 

 of the Andamanese and Nicobarese. After exhibiting and 

 describing the new objects from the Andaman and Nicobar 

 Islands, comprised in the second collection recently pre- 

 sented by him to General Pitt-Rivers, the author gave a 

 slight sketch of the aborigines of the former group ; he stated 

 that they are divided into at least nine tribes, linguistically dis- 

 tinguished, and in most, if not all, of these there are two 'dis- 

 tinct sections, viz. inland and coast men. In confirmation of this 



