33- 



NATURE 



[July 31, ii 



mixture of microscopic crystals of blende and galena ; it forms a 

 fine-grained saccharoidal mass, very homogeneous in structure, ex- 

 cept as regards the pyrites, and occurs in isolated crystals easily 

 discernible by the eye. The author objected to the terms which 

 had been applied to this mineral on the grounds that they were 

 too local, and did not describe the ore. He explained his 

 method of determining the actual physical as well as the chemi- 

 cal composition of the ore. In conclusion, he said that he was 

 tempted to quote from his report upon the Dublin International 

 Exhibition of 1865 in connection with the raising of silver in 

 Ireland. At that time he found that this country was a large 

 supplier of silver, but he was almost afraid to make the calcula- 

 tion now that he then made of the silver supplied by Ireland. 

 He stated that in 1865 Ireland yielded 14,000 ounces of silver 

 per annum, or 2 '4 per cent, of the whole of the silver raised in 

 the world, and its value might be estimated at 3850/. per annum, 

 exclusive of the accompanying lead. If 1000 tons of this ore 

 could be supplied, which represented of silver alone 8000 ounces, 

 how lamentable it seemed that this valuable industrial resource 

 should remain unworked. — G. H. Kinahan, M.R.I. A., notes 

 on the earthquake that took place in Essex on the morning of 

 April 22, 1884. 



Sydney 

 Royal Society of New South Wales, June 4. — H. C. 

 Russell, B. A., F. R. A. S., President, in the chair. — Three new 

 members were elected, and forty-six donations were received.— 

 The following papers were read : — On rain and its causes, by 

 Edwin Lowe, in which he advocated the firing of cannon and 

 of explosives for bringing about the precipitation of rain. — On 

 the removal of bars from the entrances to our rivers, by Walter 

 Shellshear, Assoc. M. Inst. C.E. — A specimen of scum from a 

 pond near Campbelltown was exhibited. It had been noticed 

 that the surface of the water was covered with a rich green growth 

 in the mornings, and that this changed to a deep red in the 

 afternoons. Messrs. Morris, M.R.C.S., and Wright, M.R.C.S., 

 stated that it appeared to be due to Astasia /nematodes, Ehr. 



Paris 

 Academy of Sciences, July 21. — M. Rolland, President, in 

 the chair. — Presentation of two unpublished essays of Augustin 

 Fresnel, found among the papers of Ampere, by M. Bertrand. 

 The subjects of these essays are the following : — (1) Comparison 

 of the hypothesis of electric currents round the axis of a magnet 

 with that of electric currents round each molecule of matter ; (2) 

 Second note on the hypothesis of particular electric currents. 

 These documents are both in the handwriting of Fresnel, but with- 

 out title or signature, and one only bears a date, that of June 5, 

 1821. — A study of the geometrical deformations determined by 

 the crushing of a straight cylinder in the direction of its axis 

 between two planes (two illustrations), by M. Tresca. — On two 

 theorems of Prof. Sylvester in connection with his complete 

 demonstration of the rule of Newton in the form given to it by 

 Newton himself, by M. de Jonquieres. — Note on the equation in 

 matrices px — xq (continued), by Prof. Sylvester. — On the solu- 

 tion of the most general case of linear equations in binary quanti- 

 ties, that is to say, in quaternions or in matrices of the second 

 order, by Prof. Sylvester. — Note on the maritime canals of Suez 

 and Panama, by M. de Lesseps. In presenting the report of 

 the International Commission on the widening of the Suez 

 Canal, the author expresses the hope that it will soon be able to 

 afford easy passage to ten or twelve million tons of shipping 

 yearly. The Panama Canal, he expects on the report of Mr. 

 Dingier, will be completed in the year 1S88. — On the proposed 

 formation of a so-called inland sea in Algeria and Tunisia, by 

 M. E. Cosson. The author repeats the objections already urged 

 against M. Roudaire's project, which, in the discussion that 

 ensued, was supported by M. de Lesseps. — Remarks in connec- 

 tion with the last letter received from Laperouse, dated Botany 

 Bay, February 7, 17SS, by M. de Jonquieres. — On electro- 

 capillary relations, by M. P. Garbe. — Direct measure of the two 

 static components and of the dynamic component of the mag- 

 netic field of condensing-machines, by M. G. Cabanellas. — 

 Researches on magnetism, by M. Duter. — On a new elec- 

 tric pile with carbon electrodes, producing an electromotor 

 force equal to o - 6 volt, by MM. D. Tommasi and 

 Radiguet. — On the numerical value of Poisson's coefficient 

 as determined by experiments made with caoutchouc, by M. 

 E. H. Amagat. — Temperature and critical pressure of nitrogen ; 

 boiling points of nitrogen and ethylene under slight pressures, by 

 M. K. Olszewski. — On the properties of the liquefied vapour of 



ethylene, and on its employment as a refrigerator, by M. S. 

 Wroblewski. — Action of the induction spark on benzine, toluene, 

 and aniline, by M. A. Destrem. — On the production of a crystal- 

 lised manganite of baryta, by MM. G. Rousseau and A. Saglier. 

 — On the combinations formed by the sesquichloride of chromium 

 with the other metallic chlorides, by M. L. Godefroy. — On a 

 general reaction of the polyatomic alcohols in presence of borax, 

 and of the paratungstates, by M. D. Klein. — Remarks on 

 the disinfecting properties of borax applied inwardly, by 

 M. E. de Cyon. From experiments continued over six 

 years the author concludes that borax is a powerful anti- 

 septic, and that it may be introduced in any required quan- 

 tity into the system to preserve it from all contagions caused by 

 parasites or microbes. As a prophylactic against cholera he 

 recommends boric acid or a solution of borax to be applied to 

 all the external mucous membranes, and about six grains of 

 borax to be taken every twenty-four hours with the food and 

 drink. It appears not only to act directly on the microbes con- 

 tained in the intestinal canal, but also to attack the bacilli that 

 may have penetrated into the blood. — Researches on the physio- 

 logical development of Cerocoma schnberi, Stcnot ia apicalis, and 

 other insects of the order of Cantharides, by M. H. Beauregard. 

 — Remarks on the action of the heart in insects during their 

 metamorphosis, by M. J. Kiinckel. — Note on the origin and 

 distribution of phosphorus in coal and cannel-coal, by M. Ad. 

 Carnot. — On the variation, under pressure, of the temperature 

 determining the transformation of the iodide of silver, by MM. 

 Mallard and Le Chatelier. — Researches on the inlluence of light 

 on the respiration of vegetable tissues destitute of chlorophyll, 

 by MM. G. Bonnier and L. Mangin. 



Vienna 

 Imperial Academy of Sciences, June 13. — E. Mach and 

 T. Wentzel, on the fixation of a very transitory phenomenon 

 by instantaneous photography. — E. Tangl, on the continuity of 

 protoplasm in vegetable tissue. — M. Loewit, contributions to 

 theory of blood-coagulation, ii., on the importance of the blood- 

 disks. — B. Schudel, on propylidene-dipropyl-ether. 



CONTENTS page 



Forestry 309 



Lenses 310 



Our Book Shelf:— 



Schwackhbfer's " Fuel and Water." — Prof. Fleeming 



Jenkin, F.R.S 311 



Mackay's " Elements of Euclid " 311 



Jagnaux's " Traite Pratique d'Analyses chimiques et 



d'Essais industriels " 311 



Letters to the Editor :— 



The Relation between the B.A. Unit and the Legal 



Ohm of the Paris Congress. — R. T. Glazebrook 311 

 The Yard, the Metre, and the Old French Foot.— 



Lieut. -Col. J. Herschel, R.E 312 



Fireballs.— W. J. Millar 312 



The Swallowing of one Snake by another. — Baron 



C. R. Osten Sacken 312 



The Red Sunsets. — Chas. Morris 312 



The Saltness and the Temperature of the Sea. By 



Hugh Robert Mill 313 



Specialisation in Scientific Study 314 



Two Greek Geometers 315 



The Royal Gardens at Kew 316 



Mr. Thoroddsen's Geological Explorations. By 



Th. Thoroddsen 317 



Seats in Railway Carriages. {Illustrated) 318 



A New Principle of Measuring Heat. By Otto 



Pettersson. (Illustrated) 320 



Notes 323 



Our Astronomical Column : — 



Schmidt's Variable-Star in Virgo 325 



A New Comet 326 



Scottish Metet rological Society 326 



The Philosophical Society of Glasgow 327 



Science in Russia 327 



Recent Morphological Speculations, III. (Illus- 

 trated) 328 



Scientific Serials 330 



Societies and Academies 330 



