578 



NA TURE 



[April i i, 1901 



was in each case attributed to the continuous production of ions 

 throughout the volume of the air. In the present paper a descrip- 

 tion is given of the apparatus used in Mr. Wilson's experiments, 

 and of further results obtained with it. The air, in most of the 

 experiments, was contained in a glass bulb, coated internally with 

 a layer of silver sufficiently thin to enable the position of a gold 

 leaf within the vessel to be read by means of a microscope. The 

 gold leaf was attached to a narrow brass strip, fixed by means of a 

 sulphur bead to a brass rod passing through the neck of the bulb. 

 The brass strip and gold leaf formed the whole of the system of 

 which the fall of potential was observed ; the capacity was thus 

 very small. To avoid all danger of being misled by leakage 

 through the insulating support, the rod, to which the leaking 

 system was attached by the sulphur be.ad, was kept at constant 

 potential by means of a condenser of zinc plates embedded in 

 sulphur. By a momentary contact, brought about with the aid of 

 a magnet, the initial potential of the leaking system was made 

 equal to that of the supporting rod. The rate of leakage in air 

 at atmospheric pressure corresponds to the production of about 

 twenty ions of either sign in eachc.c. per second ; the ionisation 

 is approximately proportional to the pressure. Experiments 

 made with a portable apparatus showed that the ionisation in a 

 closed vessel is the same when the experiment is performed in 

 an underground tunnel as above ground. It appears, therefore, 

 not to be due to the action of ionising radiation which has 

 traversed our atmosphere. 



"The Chemistry of Nerve-degeneration.'' By Dr. F. W. 

 Mott, F.R.S., and Dr. W. D. Halliburton, F.R.S. 



Linnean Society, March 21. — Mr. F. D. Godman, F.R.S. , 

 vice-president, in the chair. — Mr. J. E. Harting exhibited and 

 made remarks on some photographs of female roedeer ( Capreo- 

 lus capreo) bearing antlers, one of which had been shot at 

 Neudau, in East Styria, in December last. — Mr. H. J. Elwes, 

 F.R.S., considered the case so remarkable and unusual as to 

 suggest the probability of some mistake having been made in 

 determining the sex. Mr. Harting, in reply, stated that this 

 was by no means unique. In Germany, where roedeer are 

 much more plentiful than in this country, several does with 

 antlers had been recorded. Dr. Altum, in his Forstzoologie (Bd. 

 i. p. 211), states that many such cases were known to him. One 

 instance noted in the Black Forest at Kippenheim is mentioned 

 in The Zoologist, 1866, p. 435. In that case the horns were "in 

 the velvet," but perfectly hard ; one was about 6 in. long with 

 a single short tine, the other about 3 in. without any tine. A 

 female roe with budding horns was shot in October 1875 by 

 Mr. Duncan Davidson, of Inchmarlo, Banchory, Aberdeenshire. 

 The skull of another in the museum of the Royal College of 

 Surgeons, forwarded from Petworth Park, Sussex, by Lord 

 Egremont, is figured in the Proceedings of the Zoological Society, 

 1879, p. 297. Mr. Harting also pointed out that such cases 

 were not confined to the genus Capreolus, but had been noted 

 rarely in Cervus elaphus, and once in the case of the American 

 white-tailed deer Cariacus virginianus (shot in East Kootenay, 

 British Columbia), a photograph of which he exhibited. — Mr. 

 P. Chalmers Mitchell read a paper entitled " The Anatomy and 

 Morphology of the Intestinal Tract in Birds ; with Remarks on 

 the Nomenclature and Valuation of Zoological Characters." He 

 described the various conformations of the intestinal tract in 

 birds, his material consisting of many hundreds of specimens 

 belonging to all the living Ratitas as well as all the orders and 

 suborders and nearly all the families of Carinatse. He discussed 

 the morphology of the tract, distinguishing, in their adult 

 anatomy and in their relation to the embryonic metamerism, the 

 duodenum, Meckel's tract, and the rectum. He described 

 the nature and distribution of the changes in these organs and 

 in Meckel's diverticulum, and the colic caeca, and gave an 

 account of a remarkable and hitherto undescribed series of 

 nervous structures belonging to the autonomic nervous system 

 apparently peculiar to birds. In discussing the relation of the 

 series of facts described to the systems of avian classification, 

 he insisted on the primary necessity of valuing characters as 

 archicentrip or apocentric, primitive or specialised. A common 

 possession of a character in either the archicentric or apocentric 

 condition was no indication of systematic affinity. Amongst 

 apocentric characters he distinguished between multi-radial 

 apocentricities (many of which were plastic effects and afforded 

 no guide to affinity) and uniradial apocentricities which had 

 arisen by a limitation and definition of variability in a particular 

 branch of the family tree. 



Geological Society, March 20.— J. J. H. Teall, V.P.R.S., 

 president, in the chair. Prof. Friedrich Johann Becke, of 

 Vienna, was proposed as a foreign correspondent of the 

 Society. — Mr. H. B. Woodward called attention to a polished 

 slab of landscape marble, or cotham stone, from the Rhaetic 

 Beds near Bristol, which had been lent for exhibition by Mr. 

 Frederick James, curator of Maidstone Museum. The speci- 

 men showed that after the arborescent markings had been pro- 

 duced in the soft mud, some irregular and partial solidification 

 took place in the upper layers of the deposit ; and then during 

 contraction a kind of subsidence occurred of the upper and 

 harder portions into the lower and softer materials. This sub- 

 sidence was accompanied by a breaking-up of the harder portions, 

 suggesting a comparison (in miniature) with " broken beds" and 

 even crush-conglomerates. The specimen was of considerable 

 interest, as illustrating the mechanical changes produced during 

 solidification. The following communications were read : — On 

 a remarkable volcanic vent of Tertiary age in the Island of Arran, 

 enclosing Mesozoic fossiliferous rocks (communicated by per- 

 mission of the Director-General of H.M. Geological Surve) ). 

 Part i. On the geological structure, by Benjamin Neeve Peach 

 and William Gunn. The rocks which form the subject of this 

 paper cover an area of about seven or eight square miles, and 

 culminate in Ard Bheinn A'Chruach and Beinn Bhreac. They 

 are in contact with formations ranging from the Lower Old Red 

 Sandstone to the Trias, and are later in date even than the im- 

 portant faults of the area. They are made up partly of frag- 

 mental volcanic materials, and partly of various intrusive masses, 

 confined within an almost unbroken ring of intrusive rocks. In 

 addition to igneous fragments the clastic volcanic rocks contain 

 fragments derived from the surrounding formations ; and also 

 masses of shale, marl, limestone and sandstone belonging to 

 formations not now found in situ in the island. One of these is 

 several acres in extent, contains fossils, and is in part of Rhaetic 

 age ; a second is a fragment of Lias ; and a third is of limestone 

 and chert resembling the Antrim Cretaceous rocks, and yielding 

 fossils. The absence of Oolitic and older Cretaceous seems to 

 indicate a resemblance between a former succession in Arran 

 and that now seen in Antrim. — Part ii. " Palaeontological 

 Notes, by E. T. Newton, F.R.S. The masses of Rhsetic strata 

 yield Avicula contorto, Pecten valoniensis, Schizodus {Axinus) 

 cloacinus, etc. ; those of Lower Lias Gryphcea arcuata, 'Ammo- 

 nites angulatus, and new species of Nuculana and Tancredia, 

 which are figured and described. Thin slices of the Cretaceous 

 limestones prove to be very like those of the Antrim chalk, and 

 the rocks yield determinable foraminifera, Inocerami, sponges, 

 and echinoderms. — On theicharacter of the Upper Coal Measures 

 of North Staffordshire, Denbighshire, South Staffordshire and 

 Nottinghamshire ; and their relation to the productive series, by 

 Walcot Gibson (communicated by permission of the Director of 

 H.M. Geological Survey). The Upper Coal Measures of North 

 Staffordshire are capable of a fourfold subdivision, the groups 

 representing a definite sequence of red and grey strata. 



Manchester. 



Literary and Philosophical Society, March 19. — Charles 

 Bailey, vice-president, in the chair. — Mr. E. F. Morris exhibited 

 two drawings of recent excavations in the Roman Forum. The 

 one represented a rostrum, stated to be that from which Antony 

 delivered his famous speech. It is built of tufa and concrete, 

 and consists of five little vaulted rooms, as seen in the well- 

 known medal of Palikanus. The other was a sketch of a little 

 ^edicula in brick work, the front decorated with two marble 

 columns supporting an architrave on which is carved the name 

 of the deity (Juturna) to which it was consecrated. In front of 

 it is a circular welhwith an elegant marble head, ornamented with 

 a carved cornice bearing an inscription stating that the well was 

 consecrated to Juturna by Marcus Barbatius Pollio. Before the 

 well is a marble altar with a sculptured front, on which are the 

 figures of Mars and of a female deity— Juno or Venus. Signor 

 Boni has also brought to light the celebrated fountain of Juturna, 

 which is enclosed by a spacious rectangular construction in tufa- 

 work of the Republican epoch. The water now gushes out 

 fresh and clear, in abundance. The sculptures in the room 

 enclosing the spring were also described. — Mr. Thomas Thorp 

 showed photographs of the spectrum of the new star in Perseus, 

 showing the bright lines very clearly. Mr. Thorp also described 

 a variatioii in the ordinary arrangement of a star spectroscope^ 

 in which the eye-piece of the telescope used is replaced by a 



NO. 1 64 1, VOL. 63] 



