ytme 23, 1 881] 



NATURE 



183 



inducing spiral magnetism, the sounds became audible, some 15° 

 sonometer against 175° for iron ; thus the molecular rigidity of 

 steel as observed by previous methods was fully verified. 



I have, I believe, demonstrated by actual experiments which 

 are easy to repeat, that — 



F. An electric current polarises its conductor, and that its 

 molecular magnetism can be reconverted into an electric current 

 by simple torsion of its wire. 



2. That it is by the rotation of its molecular polarity alone 

 that an electric current is generated by torsion. 



3. That the path of an electric current through an iron or 

 steel wire is that of a spiral. 



4. That the direction of this spiral depends on the polarity of 

 the current, or that of its magneti-m. 



5. That a natural magnet can be produced, having its molecu- 

 lar arrangement of a spiral form, and consequently reversed 

 electric currents would both have a similar spiral in passing 

 through it. 



6. That we can rotate the polarised molecules by torsion or a 

 compound strain of longitudinal and transversal. 



7. That the rotation or movements of the molecules give out 

 clear audible sounds. 



8. That these sounds can be increased or decreased to zero by 

 means that alone have produced rotation. 



9. That by three independent methods the same effects are 

 produced, and that they are not due to a simple change or 

 weakening of polarity, as when rotation has been incomplete 

 a mere mechanical vibration has at once restored the maximum 

 effect. 



10 That heat, magnetism, constant electric currents, me- 

 chanical strains and vibrations have all some effect on the result. 



Linnean Society, June 2. — Sir John LubbocV, Bart., 

 F.R.S., in the chair. — Mr. R. Romanis of Rangoon was elected 

 a Fellow of the Society. — Dr. G. Iloggan exhibited and made 

 remarks on preparations of the lymphatics of vascular walls. — 

 Mr. Elwes exhibited samples of quinine made by a new process 

 by Mr. Gammie ot Sikkim. — Mr. Thos. Christy drew attention 

 to living rubber plants from West Africa, viz., Urostigina Vogelli 

 , and Tabirniemontanum crassa, and he showed products of 

 Pistacia terebinthiis, viz., the nuts, the resin, and the so-called 

 butter, separated from the resin, and used for sweetmeats in the 

 East, also Chian turpentine from the same tree. — Sir J. Lubbock 

 afterwards read a paper on the habits of ants, for abstract of 

 which see p. 142. — Mr. S. O. Ridley read a paper on the genus 

 Plo:ainia of Schmidt and some other Echinonematous sponges, 

 with reference to the genus mentioned, for which he accepted 

 Prof. Duncan's name of Dirrhopalum. He enumerated three 

 species already described, but assigned to other genera, « hich 

 must be added to it ; the distribution is thus extended from the 

 tropical Atlantic to the British, Portuguese and Ceylon Seas. 

 He described a New Zealand species which proves to be new to 

 science and appears to decide a point which has been disputed, 

 viz., the existence of ceratinous miterial in the skeleton. Geo- 

 logical facts were brought forward showing the existence of the 

 genus in the Eocene, Upper Chalk, and- Greensand formations. 

 A n=w genus of the same order was described, based on a species 

 of Lamarck and tno other species ; it is closely allied to Dictyo- 

 cylindrus ; its distribution extends from Arabia to Australia, — 

 Prof. Duncan also read a communication on two new species of 

 sponges of the genus Dirrhopalutn from the Atlantic sea-bed. — 

 The ninth p^rt of the Rev. Boog Watson's mollusca of the 

 Challenger Expedition, family Pleurotomidse, was read by the 

 Secretary. 



June 16. — Sir John Lubbock, Bart., president, in the chair. — 

 Mr. Alex. Somerville, Capt. J. T. Wright, and Mr. John 

 Forrest, the Australian explorer, -were elected Fellows of the 

 Society. — Mr. W. Hood Fitch exhibited a set of folio drawings 

 of new orchids, species of Odonto«lossiii>i. — The Rev. W. 

 Higgins showed a Holothurian (Psoliis sqtianiatus) got between 

 the Falklands and Patagonia, originally figured by Otho Fred. 

 Miiller in his "Zoologia Danica," and now recorded of wide 

 distribution. — A letter was read from Mr. W. Ferguson of 

 Colombo, mentioning his having found Wtj/^'ir arr/iiza, Wimm., 

 in abundance, and discovery of Adiaiitnm .^thiopician, L., in 

 the Kandyan country, both plants being new to Ceylon. — Mr. 

 J. G. Baker exhibited a specimen of the inflorescence of Aloe 

 Paryii, which had flowered for the first time in this country, 

 although the drug obtained from the plant had been known for 

 2000 years. — S urgeon- Major Aitchisn then read a communica- 

 tion on the flora of the Kuram Valley, Afghanistan (Part II.) ; 



he showed by a map the peculiarities of the vegetation of the 

 district, and in illustration of his paper referred to a series of 

 dried specimens of the plants and the products in use by the 

 natives, and otherwise characteristically interesting. — The next 

 paper read was on Central African plants collected by Major 

 Serpa Pinto, by Prof Count Ficalho .and W. P. Hiern. The 

 specimens herein discussed were collected by Major Serpa Pinto 

 in the month of August, 1878, along the upper course of the 

 River Ninda, an affluent of the Zambesi, on the west side of the 

 high plateau. As regards the climate of this locality the tem- 

 perature is described as variable, the weather as very dry during 

 seven or eight months of the year, and very wet during two or 

 three months. The nature of the soil is metamorphic argil- 

 laceous schist ; the latitude is 14° 46' S., the longitude 20° 56' E., 

 and the elevation 1143 metres above the ocean. The rest of the 

 botanical collections made by Major Serpa Pinto at different 

 points of the journey, which were much more considerable, were 

 lost. The present little collection consists of seventy-two num- 

 bers, comj rising sixty- five species in thirty-nine genera; twelve 

 of these species are new or not previously described and pub- 

 lished, and at least one new genus ajipears amongst them. 

 Some of the specimens are too imperfect for final determination, 

 and several of the grasses and sedges can only be generally 

 referred to their approximate position, and not specifically ascer- 

 tained. In the case of the previously-known species, the affini- 

 ties of many of the species are not only with the flora of Huilla 

 in South Angola, but also in several instances witli that of 

 extra-tropical South Africa ; only a few of the species are widely 

 distributed in the tropics of this and other continents. — There 

 followed a paper by Mr. Edward J. Miers, viz., revn'sion of the 

 Idoteidae, a family of Sessile-eyed Crustacea ; and another by 

 Prof. Ewart on the nostrils of the Cormorant. Certain structural 

 peculiarities in the latter were described, these apparently ac- 

 counting for or being related to a certain extent with the habit of 

 the bird of flying with its mouth open. 



Physical Society, June 11. — Lord Rayleigh in the chair. — 

 New Members : Mr. J. E. H. Gordon and Mr. J. E. Stead, 

 E.I.C. — Prof. Fleming exhibited a new form of B.A. imit- 

 resistance coil devised by him for experiments in the Cavendish 

 Laboratory, with a view to obviate the leakage in the older form 

 due to condensed moisture on the paraftin insulating the elec- 

 trodes, and also to facilitate the equalisation of the temperature 

 of the coil with the medium it is placed in. For this purpose 

 the wire is wound bare, each layer being insulated from the 

 rest by ebonite fenders nitched to receive the turns, and the 

 coil is inclosed in a brass box screwed together. This box is 

 water-tight, and may be .=oIdered or provided with a leaden 

 washer between the two flanged halves, which screw together. 

 Dr. Stone said he usually insulated the B.A. coil, when 

 plunging it in water, by putting it in a beaker of paraflSn 

 oil, which was immersed in turn in the water. Prof. 

 Ayrton pointed oat the advisability of makers aiming rather 

 at turning out exact resistances of any definite value, rather than 

 wasting time and increasing the cost of the coils by adjusting 

 them to a given figure, such as i or 10 ohms. — Prof. W. 

 Chandler Roberts read a paper on the hardening and tempering 

 of steel. He pointed out that few questions connected with the 

 metallurg)' of iron or steel are attracting more attention now 

 than the relation between a metal and the L-ases it comes into 

 contact with during manufacture. The carburisation of iron has 

 long been of irreat interest, as sho\vn by the work of Clouet at 

 the end of last century, and that of Margueritte in 1S65, who 

 showed that though the conversion of iron into steel could be 

 effected by contact with carbon even in the diamond form, it is 

 nevertheless true that in the ordinary process carbonic acid plays 

 a considerable part which had been overlooked. Graham's 

 1867 paper on the occlusion of gases by metnl- gave point to 

 Margueritte's w-ork by showing that carbonic oxide can pene- 

 trate to the centre of a mass of iron. It is introduced, 

 in fact, at a comparatively low temperature, \\hile a high 

 temperature is necessary to enable the metal to appropriate the 

 carbon and become steel. Metallurgists are now carefully in- 

 vestigating the effect of occluded gases in iron and steel. Prof. 

 Roberts c- n-idered the point recently raised as to whether the 

 hardening and tempering of steel might not be influenced by the 

 occlusion or expulsion of gas. He described experiments by 

 which he proves that, as steel hardens when rapidly cooled in 

 vacuo, gases could not play any part in the temiiering. He also 

 dwelt on the precautions necessary to keep the metal in the 

 experiment free from occluded gas. He then showed that 



