July 2, 1896] 



NA TURE 



215 



way in which the increment of C and the decrement of \' are 

 made. He supposes that if the experiment is made in a parti- 

 cular way a new slope is obtained which is proportional to what 

 we call the true resistance, and hence gets a new definition of 

 the quantity d\'ldC He (the speaker) endorsed all Prof. Ayrton 

 had said as to the interest of the model exhibited. The question 

 is, Is there anything in the arc which acts as a source of energy 

 to the circuit, either as a negative resistance or as an adjuvant 

 E.M.F. ? Mr. Frilh's experiments do not give us any hint as to 

 the point where the negative resistance occurs, and the absence 

 of any such energy-giving portion of the arc is rendered |irobable 

 by the f;»ct that the arc itself is hotter than the crater. In reply 

 to Mr. Carter, the anomalies which occur with cored carbons are 

 so great as to prevent any argument being based on their 

 behaviour. The Chairman (Captain .\bney) said that the mere 

 fact that the quantity rfV/u'C had been defined in two distinct 

 ways, showed that the definitions would have to be modified in 

 some way. 



Zoological Society, June i6. — Sir William II. Flower, 

 K.C.B., F.R.S., President, in the chair. — Mr. E. E.Austen 

 gave an account of a journey undertaken by Mr. F. O. Pickard- 

 Cambridge and the author up the Lower Ainazons, on board 

 Messrs. Siemens Bros, cable s.s. Faraday, for the purpose of 

 making zoological collections on behalf of the British Museum. 

 No terrestrial mammals were met with, but obiiervations were 

 made on the two species of freshwater dolphins (Inia gfoffroy 

 ensis and Sotalia tuciixi, or S. fittvialilis), which are extremely 

 abundant in the Lower Amazons. .Among the birds, the only 

 species of special interest collected were a little goatsucker from 

 Manaos, referred provisionally to Nyttiprogne leucopygia, and a 

 woodpecker (Ce/eiis ochraieiis), of which the British Museum 

 previously possessed but two specimens. The reptiles and 

 amphibians met with all belonged to well-known and widely dis- 

 tributed forms, and the chief interest of the collections centred 

 in the invertebrates. Among these Mr. Pickard-Cambridge 

 made a large collection of spiders, including an extensive series 

 of the large hairy Therephosida;, eleven species of which were 

 pronounced to be new. An interesting collection of the nests of 

 some of these forms was also obtained. Mr. Cambridge like- 

 wise secured several specimens ol Peripa/us. Mr. Austen, who 

 devoted himself chiefly to insects, obtained some 2500 specimens 

 of diflerent orders, of which it was expected that a fair propor- 

 tion would prove to be new. Attention was drawn to some 

 interesting examples of mimicry. — Mr. P. Chalmers Mitchell 

 read a " Contribution to the Anatomy of the Hoatzin {OpistJio- 

 comiis crisla/iis)." He stated that from the characters of the 

 alimentary canal, the hoatzin might be placed either between the 

 sand-grouse and the pigeons, or between the Galling and the 

 Cuculidit. He described some interesting individual variations 

 in the condition of the anibiens muscle, and referred to other 

 points in the muscular anatomy. — Mr. G. \. Boulenger, F. R.S., 

 gave an account of the occurrence of Toniistoma schlegeli in the 

 Malay Peninsula, and added some remarks on the atlas and axis 

 of the Crocodilians. — .A communication was read from Mr. W. 

 Schaus containing notes on Walker's American types of Lepi- 

 doplera in the University Museum, Oxford. — Mr. Hamilton H. 

 Druce read a paper entitled " Further Contributions to our 

 knowledge of the Bornean Lycsnidie," in which he referred to 

 about forty species of this family not hitherto recorded from 

 Borneo. A number of these were new, and were now described 

 by .Mr. G. T. Bethune Baker and the author— Mr. F. G. 

 Parsons read a paper on the anatomy of Pctrogale xanthopiis as 

 compared with that of other kangaroos. — Dr. J. Anderson, 

 F. U.S., communicated on behalf of Miss M. E. Durham some 

 notes on the mode of swallowing eggs adopted by a South 

 African snake, Dasypeltis scabra, as observed in the specimens 

 now living in the Society's tlardens, and illustrated by a series 

 of drawings. — Mr. F. O. Pickard Cambridge read a paper on 

 the spiders of the family Aviculariid;e taken during the expe- 

 dition up the Amazons previously described by Mr. Austen. — 

 Mr. G. A. Boulenger, F.R.S., read the description of a gecko 

 which he jjroposed to refer to a new genus and species as 

 Minu'lozooii ftmL'eri, in honour of Mr. Stanley Flower, who had 

 obtained the specimen at I'enang. 



Royal Meteorological Society, June 17. — Mr. E. Mawley, 

 President, in the chair. — Mr. H. Ilarries read a paper on 

 .\rctic hail- and thunder-storms, in which he showed that the 

 commonly accepted opinion that hail- and thunder-storms are 

 almost, if not quite, unknown in the Arctic regions is incorrect. 



NO. 1392, VOL. 54] 



He had examined 100 logs of vessels which had visited the 

 Arctic regions, and found that out of that number no fewer than 

 73 showed that hail was experienced at some time or other. 

 Thunder-storms were not so frequent as hail, but they have been 

 observed in seven months out of the twelve, the month of greatest 

 frequency being August. Mr. Harries is of opinion that the 

 breeding- place of thunder-storms in these high latitudes is in the 

 neighbourhood of Barent's Sea. — A paper, by Mr. J. E. Cullum, 

 on the climatology of Valencia Island, was also read. The 

 observatory at \'alencia, which is under the control of the 

 Meteorological Oftice, is situated on the extreme south-west 

 coast of Ireland, and is almost the most westerly point of 

 Europe. Continuous records from self-recording instruments 

 were carried on from 1S69 until 1891, when the observatory was 

 removed to Caherciveen, and the author gives the results of the 

 observations for these twenty three years. 



Royal Microscopical Society, May 20. — Mr. A. D. 

 Michael, President, in the chair. — Mr. F,. M. Nelson exhibited 

 and described a small portable microscope, which had been de- 

 signed by Dr. Ross for the investigation of ca.ses of malarial 

 fever. The President said that the instrument seemed to be very 

 compact, and in this respect would no doubt lie found of great 

 value. Mr. J. E. Ingpen wished something could he done in 

 designing microscopes of this kind to get them to fold up a little 

 flatter. — Mr. J. Rheinberg's paper, on an addition to the 

 methods of microscopical research by a new way of optically 

 producing colour contrast between an object and its back- 

 ground, or between definite parts of the object itself, was read 

 by Mr. Nelson. 



June 17. — The Rev. Canon Carr, Vice-President, in thechair. 

 — Surgeon V. Gunson Thorpe, R.N., exhibited and described 

 some Rotifera, preserved after Rousselet's method, which he 

 had collected whilst on the China station. — Lieut. -Colonel 

 Siddons, R.A., exhibited and described a portable microscope 

 which he considered met the suggestion offered by Mr. Ingpen 

 at the previous meeting. — Mr. Conrad Beck read the report of 

 the sub-Committee of the Council on screw-tools. 



Paris. 

 Academy of Sciences, June 22. — M. A. Cornu in thechair. 

 An expression for the skin friction in the irregular flow of a 

 fluid, by M. T- Boussinesq. — Some properties of the primitive 

 roots of prime numbers, by M. de Jonquieres. — On the caustic 

 of an arc of a curve reflecting rays emitted by a luminous point, 

 by M. A. Cornu. — On the formation of gaseous and liquid hydro- 

 carbons by the action of water upon metallic carbides. Classi- 

 fication of the carbides, by M. H. Moissan. A resume of the 

 work done by M. Moissan and his pupils upon metallic carbides, 

 together with some remarks on the geological bearing of the 

 results. — Remarks on a work entitled "Microbial and animal 

 toxins," by M. A. Gautier.— Observations on Swift's comet 

 (April 13, 1896) made with the large equatorial at the Observatory 

 of Bordeaux, by ilM. G. Rayet, L. Picart and F. Courty.— 

 Dr. Gill was elected a Corresponding Member in the Section of 

 Astronomy in the place of the late Prof. Cayley.— On the zero 

 of Riemann's function s,'(j), by M. Hadamard.— On the X-rays, 

 by M. C. Maltezos. Some theoretical considerations as to the 

 possible nature of the rays.— An electrolytic method of de- 

 silverising argentiferous lead, by M. D. Tommasi.— Magnetic 

 anomaly observed in Russia, from a letter by M. Moureaux to 

 M. Mascart. In the village of Kotchetovka (lat. 51°, long. 6" 8' 

 east of Poulkowa) determinations of the magnetic elements at 

 fifteen points within an area of one square kilometre gave values ' 

 for declination varying between -F 58° and -43°; for inclination, 

 from 79" to 48", and for the horizontal component, o-l66 to 

 0-589. The latter figure, which is the highest value of the 

 horizontal component hitherto oljserved, was carefully controlled 

 by six measurements at neighbouring points, from the results of 

 which figures between 0-48 to 058 were obtained. — On the 

 dark blue nitrosodisulphonic acid, by M. Paul Sabatier. By the 

 action of cuprous oxide upon strong sulphuric acid containing a 

 little nitrite, a deep blue colour is produced, the absorption 

 spectrum of which is closely analogous to that produced by 

 Fremy's potassium oxysulphazotinate (nitrosodisulphonate). The 

 same coloration can be produced by pa,ssing a current of nitric 

 oxide mixed with air into sulphuric acid saturated at 60° with 

 sulphurous anhydride.— On the preparation of aluminium alloys' 

 by a chemical reaction, by M. C. Combes. A mixture of 

 aluminium with a sulphide or chloride is heated till the reaction 



