520 



NA TURE 



\_March 27, 1884 



and were never more tban four feet in ihickness. The ore was dis- 

 tributed in broad rudely parallel diagonal bands, and the veins 

 resembled in this as in other particulars those of the Upper Harz 

 belonging to von Groddeck's "Type Clausthal." Lead ore was 

 discovere°d at Tyndrum in 1741, and was mined with varying 

 activity till 1S62, when the mines were abandoned, as they had 

 quite ceased to pay expenses. Chrome iron ore was knoivn to 

 occur in considerable quantity in a mass of serpentine at C^'irie 

 Chaniaig in Glen Lochaig, but had never been extensively 

 worked. An interesting occurrence of grey and yellow copi er 

 ore was found at Tomnadashan on the southern shore of I-och 

 Tay. The ore was disseminated through a mass of crystalline 

 rock resembling diorite, whicli had been injected into the schists, 

 hardening and contorting them at its edges. The basic rock was 

 in turn traversed by multitudes of veins of pink granitite, which 

 at some places united and formed a stock-like mass with large 

 pnik orthoclase crystals. The ore was found most abundantly 

 at the junction of the two rocks. Molybden glance occurred in 

 the acid rock, but no traces of blende or galena had been dis- 

 covered at Tomnadashan. At Corrai Bui near Ardeonaig rich 

 argentiferous galena veins traversed the schists on the top of a 

 hill which was capped by a series of calcareous beds. The 

 galena contained from 8$ to 600 ounces of silver per ton of ore, 

 but the veins thinned out on passing down into the non-calcareous 

 beds below, and became quite barren at a depth of 100 feet. 

 There were many other very thin veins of pyrites, blende, galena, 

 &c., in the Breadalbane district, but none were thick enough to be 

 worked with profit. — Prof.CossarEwart, F.R.S.E., exhibited, with 

 remarks, the following specimens : — { i ) the Tadpole fi^h [Raiiiccps 

 Irifurens) ; (2) the Great Fork-beard [Phycis blcnniodes) ; (3) the 

 Power Cod (Gadus mhniliis); (4) an Albino specimen of the 

 Haddock (Gadus agUfinus). — Prof. Ewart also exhibited and 

 described a new hatching-box he had devised for adhesive eirgs 

 t ) take the place of the American "Clark " hatching-box. The 

 Ofi vantage of Prof. Ewart's box is that the glasses are arrange 1 

 in a horizontal position, so that the embryos, when hatched, 

 pass at once into comparatively still water, instead of having to 

 run over and under a varying number of vertical glass plates. — 

 Prof. Ewart also described an easy method of stocking spawning 

 beds capable of being readily used by the fishermen themselves. 

 All that %\ as required « as an ordinary wooden tub and a shallow 

 galvanised iron tray about twenty inches in diameter, with the 

 bottom consisting of two portions each hinged to a central bar 

 so as to open downwards. The object in view is to deposit 

 stones on the spawning bed coated with fertilistd ova. To do 

 this the tray is placed In the tub, which is then filled with sea- 

 water. Into the tray a number of flat stones are arranged ; the 

 water is then fertilised and the stones coated with eggs. This 

 done, the tray is lowered to the bottom by means of four cords 

 — two attached to the rim of the tray, and one to each half of 

 the bottom. When the tray has reached the sea-floor, the cords 

 attached to the false bottom are set free, and the tray raised by the 

 cords attached to its edge, the result being that the egg-coated 

 stones are left at the bottom. By this method the fishermen, with- 

 out any trouble or expense, could add 200 or 300 eggs for every 

 herring they removed from the sea, and thus do their best to 

 restore" the balance of nature which their operations had 

 disturbed. 



Paris 

 Academy of Sciences, March 17. — M. Rolland in the chair. 

 — On the new map of Tunis to the scale of I : 200,000, now- 

 being prepared in the French War Ofiice, and the first six 

 sheets of which have just appeared, by M. F. Perrier. The 

 map, which will be completed early next year, will comprise 

 twenty sheets altogether, uniform with that of Algeria, of which 

 it forms a natural continuation. — Relative rapidity of combustion 

 of explosive gaseous mixtures, by MM. Berthelot and Vieille. — 

 On the solution of a very extended ckass of equations in quater- 

 nions, by M. Sylvester. — Notice of the labours of the late M. 

 Sella, Corresponding Member of the Section of Mineralogy, by 

 M. naubree. — Notice of the second volume of the Emperor of 

 Brazil's "Records of the Rio de Janeiro Observatory," by M. 

 Faye. — Remarks on a note by Sir Richard Owen on the di<;- 

 covery of a mammal (Tritylodoii) in the South African Trias, by M. 

 Albert Gaudry. — Application of the incandescent lampfor the light- 

 ing of astronomical instruments, by M. G. Towne. — Remarks on 

 the shadows cast by the facula' on the penumbra of the solar spots 

 (one illustration), by M. E. L. Trouvelot.— On some arithmetical 

 applications of the theory of elliptical functions, by M. Stieltjes. 

 — On a new generalisation of the Abelian functions, by M. E, 



Picard. — On the thrust of a mass of sand with horizontal upper 

 surface against a vertical or inclined wall, by M. J. Boussinesq. 

 — Theory and practical formulas of magneto-e'ectric machines 

 with alternate current-, by M. Felix Lucas. — Note on Hall's elec- 

 tro-magnetic phenomenon, by M. A. Leduc. — On the laws regu- 

 lating the decomposition of salts in water, by M. IL Le Chate- 

 lier. — Note on the action of chloruretted aldehydes on benzine 

 in the presence of chloride of .aluminium, by M. Alph. Combes. 

 — On the addition of chloride of iodine to monobromuretted 

 ethylene, by M. Louis Henry. ^Note on the dialysis of the acii 

 of the gastric juice, by M. Ch. Richet. — Distnliution of the 

 motor roots in the animal muscular sy^tem, by MM. Forgue 

 and Lannegrace. — Memoir on the relations between i)lants and 

 the nitrogen consumed by them, by M. W. O. Aiwater. — Note 

 on the cultivation of the sedimentary matter brought up from 

 great depths by the dredgings of the Tra-jailkur and Talisman 

 during the expeditions of 1882-83, by M. A Certes. The 

 object of these experiments is to show that the absence of plants 

 or animals in decomposition at the bottom of the sea is probably 

 due to the presence of microbes analogous to those which, under 

 our eyes, arc daily working a', the transformation of organic into 

 inorganic matter. — On the renal organs of the embryos of Helix, 

 tiy M. P. de Meuron. — On spermatogenesis a' d the phenomena 

 of fecundation in Ascaris me(;alocephala, by M. P. Hallez. — On 

 the Simradosaurian, a reptile belonging to the Cernay formation 

 of the Rheims district, by M. Victor Lemoine. — On the morpho- 

 logical value of the cortical libero-lignoje masses in the stems of 

 the CalycantheK, by M. Oct. Lignier. 



CONTENTS Page 



The Cholera Bacillus 497 



The Science of the Examination-Room 497 



Lefroy's Magnetic Survey in Canada. By Sir F. J. 



Evans, F.R.S 49^ 



Excursions of an Evolutionist. By George J. 



Romanes, F.R.S 5°° 



Our Book Shelf:— 



" The Zoological Record for 1882" 5°° 



Potanin's " Sketches of North-Western Mongolia " . 501 

 Letters to the Editor : — 



Quintino Sella.— Prof. Thos. McKenny Hughes, 



F.R.S SO' 



Electrostatic Measurement of E.M.F. — George M. 



Minchin 5°' 



Pons' Comet. — A. S. Atkinson 501 



The Access to Mountains and Moorlands Bill. — A. 



Craig-Christie 5°- 



A Sixth Sense.— Henry Faulds ; Sir William 



Thomson, F.R.S 5°- 



Earthworms.— James Melvin ; Dr. Hy. F. Walker 502 

 The Remarkable Sunsets.— J. N. Hayward; 



B. W. S 5°3 



"Curious Habit of a Brazilian Moth."— Rev. R. 



Baron 5°3 



Representation of Students.- Another Certificated 



Student of Girton College 503 



" Suicide " of Black Snakes.— Dr. James Donnet 504 

 Unconscious Bias in Walking. — ^J. E. Smith . . . 504 

 Recent Weather in North America.— Prof. Samuel 



Hart 504 



Education in the United States 504 



Pathological Anthropology. By Prof. A. H. Keane 508 

 The German Expedition to Soiith Georgia .... 509 

 Allen Thomson. By Prof. John G. McKendrick . 510 



Quintino Sella 5" 



Notes 5" 



An Improved Thermo-electric Pile for Measuring 

 Small Electromotive Forces. By Dr. G. Gore, 



F.R.S. 5'3 



The Reversal of Hall's Phenomenon. By Shelford 



Bidwell {With Diagram} SU 



Dr. Feussner's New Polarising Prism. By Rev. 



Philip R. Sleeman (fF;//; /^;«-""'") 5>4 



On Various Suggestions as to the Source of Atmo- 

 spheric Electricity. By Prof. Tait 517 



University and Educational Intelligence 517 



Scientific Serials 5'^ 



Societies and Academies 518 



