46 



NA TURE 



[May II, 1893 



apparently repelled on touching the wire with the finger. The 

 author also showed that fan-shaped luminosities could be pro- 

 duced by rotating an exhausted tube in the electrostatic field 

 produced by a charged ebonite or glass rod. Dr. Sumpner, 

 speaking of the apparently unclosed discharges, pointed out that 

 they might be closed through the wire forming the primary cir- 

 cuit, in the same way as the coil of a transformer might be 

 arranged to act partly as primary and partly as secondary. Mr. 

 A. P. Trotter, after referring to Dr. Bottomley's researches, 

 said it was important in discussing such experiments to distinguish 

 between electrostatic and electromagnetic effects. In Mr. Camp- 

 bell Swinton's experiments the luminosity always appeared to 

 get as far away from the wire as possible and to be at right angles 

 to it, whereas in Mr. Rimington's the luminous portions were 

 close to the wire. With a view to puzzling the discharge in Mr. 

 Swinton's tubes he had made a right-angled bend in the spiral 

 surrounding the tube, the result of which was to make the 

 luminosity discontinuous, one end of the break being bifurcated. 

 In all Mr. Swinton's ex43eriments brush discharges surrounded 

 the wire. Prof. S. P. Thompson thought an electrostatic 

 field would aid a discharge even if its direction was not the same 

 as the E.M.F. due to varying magnetic induction. Plante had 

 found that vacuum tubes through which 800 cells were insufficient 

 to produce a discharge, immediately allowed a discharge to pass 

 when a rubbed ebonite rod was brought within about 10 feet 

 distance. This effect was found to be independent of the direc- 

 tion of the disturbing field. Analogous effects had also been 

 observed by Prof. Schuster, and described in his Bakerian 

 lecture. Mr. E. W. Smith regarded the stresses set up in the 

 medium as cumulative, a very slight cause acting on a substance 

 already strained nearly to breaking point, being sufficient to 

 cause breakdown. Mr. Blakesley inquired if the effects were 

 the same if the induction coil, used in one of the experiments, 

 was replaced by an electric machine, and whether the direction 

 of the field so produced influenced the result. Mr. W. R. 

 Pidgeon said closed circuits were necessary, and he had found 

 it very difficult to produce discharges in tubes unless the ends of 

 the primary wire were brought together. In his reply Mr. 

 Rimington said each turn of the luminous spiral formed a com- 

 plete circuit of itself. The phenomena observed by Mr. Camp- 

 bell Swinton were quite different to those he had shown, and 

 due to different causes. Mr. Swinton's spirals were reversed, 

 and were due to phosphorescence of the glass. 



Zoological Society, April 18.— Sir W. H. Flower, 

 F.R.S., President, in the chair. — The Secretary read a report 

 on the additions that had been made to the Society's mena- 

 gerie during the month of March, and called special attention 

 to three While-tailed Gnus (Connochceles gnu) from the Trans- 

 vaal (a male and two females), obtained by purchase March 7, 

 and to three Springboks {Gazel/a euchore) from South Africa, 

 deposited by H. R.H. the Prince of Wales. — Mr. Sclater 

 exhibited and made remarks on a specimen of a curious 

 variety of the Pig-tailed Monkey (Macacus nemestrinus) from 

 the Baram River, Sarawak, lately living in the Society's mena- 

 gerie. — Mr. Sclater read a communication received from 

 General Sir Lothian Nicholson, Governor of Gibraltar, respect- 

 ing the Barbary Apes {Macacus inuus) living on the Rock of 

 Gibraltar, which were stated to have increased of late years, 

 and were now supposed to be nearly sixty in number. — Mr. W. 

 L. Sclater made some remarks on the principal animals noted 

 in the Zoological Gardens of Antwerp and Amsterdam, which 

 he had lately visited. — A communication was read from Mr. 

 A. E. Shipley containing an account of the anatomy and his- 

 tology of two Gephyrean worms of the genus Sipunculus from 

 Zanzibar, together with a few observations on Sipunculids in 

 general. — Mr. Oldfield Thomas gave an account of a small 

 collection of Mammals obtained in Central Peru by Mr. J. 

 Kalinowski. Amongst several species represented in this col 

 lection, either new or of such interest as to deserve a record 

 was especially noted a new form of Rodents of the family, 

 Muridse, proposed to be called Ichthytmys stohmanui. — Mr. 

 H. J. Elwes read a communication from Mr. W. Warren 

 describing a large number of new species and new genera of 

 Moths of the family Geometridas in Mr. Elwes's collection, 

 from SiUkim and other districts of India. Notes on the locali- 

 ties and on other points were added by Mr. Elwes. 



Geological Society, April 26,— W. H. Hudleston, F.R.S., 

 President, in the Chair. — The following communications were 

 read : — The origin of the crystalline schists of the Malvern Hills, 



NO. 1228, VOL. 48] 



by Dr. Charles Callaway. This paper was the third of a series 

 of three. In the first of these, published in the Quarterly jfournal 

 in 1887, the author contended that many of the gneisses and 

 schists of Malvern were formed out of igneous rocks. In the 

 second, which appeared in the Journal in 1889, he discussed the 

 origin of secondary minerals at shear-zones in the Malvern rocks, 

 and arrived at the conclusion that all the mica and much of the 

 felspar, to say nothing of quartz and other minerals, were of 

 secondary origin. In the present paper the author first pointed 

 out that some of the most important mineral changes described 

 in his second communication — such, for example, as the con- 

 version of chlorite into biotite — had since been confirmed by 

 independent investigators. He held that, as a whole, the gneisses 

 and schists of Malvern had been formed by the crushing and 

 shearing of consolidated igneous rocks ; but he did not deny the 

 possibility that here and there the foliated structure might have 

 been produced in a fused mass. In the first stage of metamorphism 

 the diorite or granite was crushed and decomposed. This slightly 

 compressed rock could be traced step by step into a typical gneiss 

 or schist. The signs of pressure progressively increased, and 

 the mineral and chemical changes became proportionately 

 greater. Reconstruction set in. The process of metamorphism 

 did not always follow the same lines. Felspar was sometimes 

 crushed into seams of fragments, and these, by partial refusion 

 and pressure, were converted into gneissose lenticles of quartz 

 and felspar. Intervening chlorite was changed to biotite, or 

 even to muscovite or sericite. Thus a typical gneiss, consisting 

 of quartz-felspar lenticles in a felt- work of mica, was formed o Jt 

 of a diorite. Sometimes the felspar was reconstituted without 

 becoming fragmental ; and it was then deposited on, or it included, 

 idiomorpliic mica. Or a soda lime felspar might, by a process 

 of corrosion, be converted into quartz, or a soda-felspar, or both. 

 In an early stage of metamorphism, the rock was often diity and 

 rotten through the abundance of chlorite and disseminated iron 

 oxide. The former being changed to mica, and the latter being 

 either absorbed in the production of biotite, or reconstituted in a 

 crystalline form, a sound clear gneiss was the result. In the 

 completed product, the signs of crushing and shearing were ofier> 

 entirely wanting. Even strain-shadows were rare in it. The 

 metamorphism, however, was demonstrated in numerous 

 localities by tracing the gradations inch by inch, and by the 

 subsequent study of large numbers of microscopic slides, in 

 which the transition was still more clearly £een than in the field. 

 The classification of the Malvern schists originally proposed wjs 

 somewhat enlarged, the injection-schists being subdivided into 

 — (i) Schists of primary injection, in which one rock was injected 

 into another, and (2) Schists ofsecondary injection, formed by 

 the infiltration of secondary minerals along shear-planes. One 

 of the most important of the chemical changes produced in the 

 conversion of a diorite into an acidic schist was the eliminatiot> 

 of magnesia. This was proved by analysis. The recent researches 

 of Mr. Alexander Johnstone had shown that even in the 

 laboratory, and at the ordinary temperatures, carbonated waters 

 were able to remove magnesia from certain of its combinations 

 with silica. The reading of this paper was followed by a 

 discussion, in which the President, Prof. Bonney, Mr. Harker, 

 Mr. Rutley, Prof. Hull, and the author took part. — Supple- 

 mentary notes on the metamorphic rocks around the Shap Granite 

 by Alfred Harker, and J. E. Marr,F.R.S. This paper contains 

 some additions and corrections to the work submitted to the 

 Society by the authors on a previous occasion (see Quart. Joiirn. 

 Geol, Soc. vol. xlvii. p. 266). In the present communicatiort 

 special attention is paid to the alteration of a group of basic- 

 volcanic rocks by the granite. Some remarks were made on 

 this paper by the President, Mr. Rutley, Mr. Teall. Mr. Harker 

 and Mr. Marr replied. 



Linnean Society, May 4. — Prof. Stewart, President, in the 

 chair. — Dr. R. B. Sharpe exhibited some new and rare birds 

 from Borneo, and made remarks upon the singular distribution 

 of the genera to which they belonged. On behalfofMiss E. M. 

 Sharpe he also exhibited both sexes of the larvae and cocoons of 

 a rare silkworm moth, Gonometa fascia from Lagos. Prof. J. B. 

 Farmer exhibited under the microscope some preparations 

 showing attraction spheres in Hepatic spores, and gave the 

 result of his recent researches on the subject. — Mr. Thomas- 

 Christy exhibited some curious variations in foliage in plants 

 of a Sterculia from Brazil, reared from the same pod, and 

 showed also a specimen of Erythroxylon Coca in fruit. — Mr. 

 W. B. Hemsley showed two British plants which were interest- 

 ing on account of the localities, namely Empelrum nigrum 



