276 



NA TURE 



{Feb. 5, 1874 



Nov. 20.- Prof. Liiroth read a paper on reckoning by pro- 

 jections ; and Prof. Hattendorff made some observations on 

 Sturm's theorem. 



Dec. 3. — M. Enneper communicated a paper on the general 

 theory of surfaces. 



Dec. 10. — The Society celebrated its 121st anniversary. The 

 prizes for competition in the next three years were announced. 

 In the physical section the Society invites experiments on the 

 artificial production of some crystallised minerals, as stephanite, 

 pyrargyrite, grey copper ore, galena, fluor spar ; in order to 

 solution of the question how crystallised sulphur and fluor- 

 compounds have arisen in the natural state. In the mathe- 

 matical section, the Society desires an investigation of current- 

 work, i.e. the work done by the electro-motive forces in their 

 action on the current electricity, especially in its relation to the 

 heat produced from the current, and the vis vii'a produced fiom 

 it immediately in the current electricty, or mediately, in other 

 movable particles in the conductor. Papers on these subjects 

 mustbesent before Sept. 1875, in the former case, and Sept. 

 1876, in the latter. The prizes offered are fifty ducats each. — 

 Prof. Ewald communicated an interesting paper on the so-called 

 rhetorical ornaments of Oriental speech (a subject suggested, 

 apparently, by the late visit of the ' ' king of kings). " — M. Riecke 

 presented a note on the function of leal -teeth, and the morpho- 

 logical value of some leaf-nectaries. In the bud, the teeth 

 often prevent the hermetical closure of the two folded halves of 

 the leaf; whicli is perhaps important, that the bud may not 

 suffer from the ^ant of gas. A more evident function consists 

 in the separation of resin or mucilage. Priinus avium is taken as 

 a good example ; and two other types of structure are also 

 described. The teeth of leaves oi Pniitiis avium a.xe closely 

 allied, mor]ihologically, to numerous nectar-secreting organs in 

 these and other kinds of leaf. 



Dec. 17. — M. Bjerknes read a paper giving a generalisation of 

 the problem of motions produced in a still inelastic fluid by the 

 motion of an ellipsoid. — M. Wohler presented a list of the meteo- 

 rites in the University collection at Gottingen. 



Vienna 

 Imperial Academy of Sciences, Dec. 4, 1S73. — Prof. Mach 

 stated that he had made experiments, during the summer, on the 

 time required for rotation of the plane of polarisation by a cur- 

 rent — a flint glass disc being rotated between the magnetic poles; 

 but similar experiments by Villari had been described in Pi'fg. 

 Ann. (No. 7, 1873), and the results were almost identical. 

 Villari used a double plate ; and Prof. Mach points out another 

 very simple method for such researches, viz., the spectral obser- 

 vation of a sounding glass rod placed between the magnetic 

 poles. — A paper by Dr. Dvorak described some experiments 

 on the velociiy of sound in gas-mixtures. If a mixture is made 

 of two different gases, with densities d and d' respectively, and 

 both with an expansive force I, the velocity of sound V in the 



mixture = a / The author's results show close agree- 



V d + d' ^ 



ment with the theory. Thus for mixtures of carbonic acid and 

 hydrogen, air and hydrogen, ordinary gas and CO,, respectively, 

 the observed and calculated numbers for the halt wave-length of 

 a given tone were these : 7i'5, 7i'o; 88, 89'0; 64, 63'3. The 

 author remarks that for a simple gas, as well as for a mixture of 

 gases, the gas theory implies not one velocity, but a graduated series 

 of velocities, of sound ; and perhaps the prolongation in sound 

 of a cannon shot heard at a distance may be thus explained. — 

 Dr. Exner communicated a determination of the temperature at 

 which water has a maximum of density. He improved on 

 Rumford's method by usmg thermo-elements instead of a mer- 

 cury thermometer. The value obtained was 3 '945°. 



Paris 

 Academy of Sciences, Jan. 26. — M. Bertrand in the chair. 

 — The following papers were read : On the various reactions of 

 the compounds of oxygen and nitrogen, by M. Berthelot. — On 

 the production of yea; L in a mineral solution containing sugar, 

 by M. Pasteur. The author described the growth of yeast in 

 a solution of inorganic substances such as enter into the compo- 

 sition of its ash added to a solution of sugar. M. Trecul replied 

 at some length to certain of M. Pasteur's remarks.— On the 

 liquefaction and solidification of acetylene by the silent electric 

 discharge, by MM. P. and A. Thenard. The author found that 

 this gas condensed at the rate of four or five cubic centimetres a 



minute into a solid horny body isomeric with acetylene ; by 

 varying the conditions of experiment a liquid isomer was 

 also obtained. — Experimental researches on Newton's rings, 

 by M. P. Desains. — Direct demonstration of the equation 



/ ——- = o for every closed and reversible cycle, by M. A. 



Ledieu. This paper formed a sequel to the author's other 

 papers on thermo-dynamics, lately published. — Note on 

 Poncelet's teaching of applied mechanics, by General Morin. — 

 A note from Prof. Nordenskiold was read ; he has detected iron, 

 nickel and cobalt in the carbonaceous dust found in 1870 on the 

 Greenland snow ; traces of phosphorus were also found. — In- 

 structions for ^I. Doiimet-Adanson's travel in Tunis, by M. 

 Cosson. The instructions are issued to M. Adanson, who is 

 about to undertake a botanical exploration of Tunis. — On 

 magnetism, by M. J. M. Gaugain. — New researches on the 

 rejoining end to end of the fibres of sensory with the fibres of 

 motor nerves, by M. A. Vulpian. — Organogenesis com- 

 pared with androgenesis in its relation to natural affini- 

 ties, by Ad. Chatin. This portion of the authnr's paper 

 deals with the polygoiioid and cacloid plants. — Researches 

 on the silicified plants of Autun ; study of the genus Mydopteris, 

 by M. B. Kenrult. — On the presence of a considerable proportion 

 of potassic nitrate in two varieties of Amaiant/iiis, by M. A. 

 Boutin. The author found that A. atropurpureus contained 227 

 and A. ridhv i6'o per cent, of the weight of the dried plant ; he 

 suggested a possible future cultivation of the plant on this ac- 

 count.— On the theory of the flight of birds, by MM. H. and L. 

 Planavergne. — On a statistical chart showing the distribution ot 

 the population of Paris, by M. \'auihier. — On the geometrical 

 properties of rational fractions, by M. F. Lucas. — On the deter- 

 mination of the pluckerian numbers of envelopes, by M. II. G. 

 Zeuthen. — On the theory ol numerical equations, by i\I. Laguerre. 

 — On the breaking of magnetised needles, by M. Bouty. The 

 author found that if the steel was very brittle and broke like 

 glass the two portions are magnets of the same magnetic 

 moment, but not so if the steel has to be bent backwards and 

 forwards before it breaks. — On certain peculiarities in the 

 efflorescence of the two hydrates of sodic sulphate, by M. D. 

 Gernez. — Researches on the reaction of argentic chloride on 

 phosphoric di-ioclide, by M. Ar-m. Guntier. — On the isomerism of 

 terebenthene and terebene, from a physical point of view, by 

 M. J. Ribau. — On the alterations of the soft matter (of the 

 brain) accompanying the tearing and cutting back of the sciatic 

 nerve in the rabbit, by M. G. Uajem. — On the pluvial regime of 

 the torrid zones in the Indian and Pacific Ocean basins, by M. 

 V. Raulin. — Note on Professor Tyndall's experiments on the 

 acoustic transparency of air, by M. W. de Fonvieile. — On the 

 production of crystals of calcic oxalate and ammonic-magnesic 

 phosphate, by M. E. Monier. During the meeting, the Aca- 

 demy elected M. Gervais as successor to the late M. Coste, of 

 the section of Anatomy and Zoology. 



CONTENTS p.^GK 



ScrENTiFic WoRTHrEs, II. Thuhhs Henrv Huxley. I!y Ernst 



Haeckel {IViih Steel Engraving) 257 



Zoological Nomenclature. By Alfred R. Wallace, F.Z.S. . . 25S 



Results of the French ScrENTlFrc MlssroN to MExrco . ... 260 



Our Book Shelf 261 



Letters to the Editor : — 



M Barrande and Darwinism, — H. Hicks : T. R. R. Stebbing . 261 



Perception in Lower Animals. — E. H. Pringle 262 



Earthquake in New Guinea.-Dr. A. B. Meyer 263 



Sensitive Flames at the Crystal Palace Concerts. — W. N. H.\rtley 265 



The Photographic Society 263 



Astronomy in the Argentine Confederacy 264 



The Common Frog, IX By St. George Mivart. F.R.S. Wth 



Illustrations) 264 



The Acoustic Transparency and Opacity of the Atmosphere, 

 II. Royal Institution Friday Evening Discourse by Prof. Tvndall, 



F.R.S. (With Illustration) 267 



Extracts from an Address by Sir W. Thomson to the Society of 



Telegraph Engineers 269 



Notes 271 



Scientific Serials 274 



Societies and Academies . . 275 



