2r6 



NATURE 



\_yune 20, 1878 



which may be inferred from Sir W. Thomson's early experi- 

 ments and from Mr. Tomlinson's recent confirmations and ex- 

 tensions of the conclusions to which he wis led regarding the 

 effect of stress on the electric conductivity of metals. It is much 

 to be desired that Mr. Tomlinson should continue his experi- 

 ments ; but in the meantime it seems probable that the electric 

 conductivity in the outer parts of an iron wire twisted within 

 its limits of torsional elasticity is maximum and minimum in the 

 two spirals at 45° to its length, being minimum in that one of 

 them which is of the same name as the twist, that is, the one in 

 the direction of the maximum extension of the substance ; and 

 the conductivity is a maximum in the other 45° spiral which is the 

 direction of maximum contraction of the substance. The effect 

 of this seolotropic conductivity, if it exists, must be to cause the 

 electric currents to flow in spirals of opposite spirality to that of 

 the twist and to produce a corresponding amount of longitudinal 

 magnetisation. The effect of this is to develop, at the end by 

 which the current enters, a true south pole when the twist is 

 right-handed, and a true north pole when left-handed, which is 

 opposite to Wiedemann's result. And if the tangential mag- 

 netising force exceeds the critical value, the effect of the 

 asolotropic magnetic susceptibility also is opposite to Wiede- 

 mann's result. This is a subject of great interest, and requires 

 further investigation. 



Photographic Society, May 14. — J. Glaishcr, F.R.S., pre- 

 sident, in the chair. — Papers were read by Capt. Abney, K.E., 

 F.R.S., on photography at the least refrangible end of the 

 spectrum, and on some photographic phenomena, by W. 

 England, on dry plate processes, and by T. S. Davis, F.C.S., 

 on a tourist's preservative dry plate process. — Capt. Abney in 

 his paper described the means by which he obtained a photo- 

 graph of the spectrum beyond the B red line by using one of 

 Rutherford's reflection gratings containing 17,280 lines to the 

 inch, which gives a double spectrum outside a central white 

 light, the resulting negative contained 130 perfectly defined 

 lines, many never yet seen by the human eye, the wave length of 

 the lowest lines being about 10,000 tenth metres. 



Rome 

 R. Accademia dei Lincei, Mar. 3. — The following, 

 among other papers, were read : — Geological and paljeon- 

 tological studies on the middle cretaceous of Southern Italy, by 

 M. Sequenza. — On the Italian expedition to Equatorial Africa, 

 by M. Correnti. — On pensile shoots, with measurements of the 

 vertical aiid horizontal angles, by M. Robert. — Prehistoric Cala- 

 brian objects, by M. Ruggeri. — Graphic determination of the 

 forces in reticular woodwork, by M. Favero. — Statistics of 

 the mortality, diseases, and reforms of the Italian army from 

 i860 to 1875, compared with those of other European armies, 

 by M. Sormano. — On the nummulitic horizon near Castelnuovo 

 deir Abate, in the province of Siena. 



Paris 

 Academy of Sciences, June 10. — M. Fizeau in the chair. — 

 The following among other papers were read : — On the cubes or 

 prisms of M. Rohart for the destruction of phylloxera, by M. 

 Chevreul. He finds they contain about thirty per cent, sulphide 

 of carbon. Their efficacy surprises him. — On the large number 

 of joints, mostly perpendicular to each other, which divide the 

 meteoric iron of Santa Catharina (Brazil), by M. Daubree. In 

 a weight of 23 kilos, were found 1,350 small fragments of iron, 

 each about 17 grammes weight ; this would give 25,000 for the 

 500 kilos, which have come to Europe. — On the source of 

 excito-sudorsal nerve-fibres of the anterior limbs of the cat, by 

 M. Vulpian. They come principally from the spinal nerve, 

 with the spinal roots of the upper thoracic ganglion ; but some 

 come directly from the cord by the roots of the nerves forming 

 the brachial plexus, — Experiments proving that the nerve-fibres, 

 whose excitation causes dilatation of the pupil, do not 

 all proceed from the cervical cord of the great sympa- 

 thetic, by M. Vulpian. Some come directly from the ence- 

 phalon, mixed probably with fibres of cranial nerves, whose 

 branches enter into connection with the ophthalmic ganglion. 

 — M. Lecoq de Boisbaudran was elected Correspondent for 

 the Section of Chemistry, in room of the late M. Malaguti.— 

 On the geographical distribution of Mexican Graminese, by 

 M. Fournier. He has brought the number up to 638. He 

 divides them into two groups^ the one special to Mexico, or 

 partly common to the Andine and northern regions, distinguished 

 by slenderness of leaves and panicles ; and the other expanded 

 in the tropical region and noted for larger size. The former 



inhabit, by preference, mountainous and dry parts ; the latter 

 the banks of rivers and moist parts. — On the artificial produc- 

 tion of natron or natural carbonate of soda, by the action of 

 carbonate of magnesia on chloride of sodium, by M. Cloez. 

 This is done at ordinary temperature. The author thinks the 

 phenomenon may occur in nature, explaining at once the 

 production of natron and the large quantity of chloride of 

 magnesium found in solution in the water of salt lakes. — Oi» 

 modifications produced in the animal system by vai'ious albumi- 

 noid substances injected into the vessels, by MM. Bechamp and 

 Baltus. They experimented on dogs both with solutions of natural 

 albumen and with pure albumens of known rotatory power. The 

 latter were not, or were only partly, eliminated. — Influence of the 

 physical state of gallium on its electro-chemical role, by M. Reg- 

 nault. He made a small couple (about 489 mm.) of which the 

 two metallic elements were solid and liquid gallium, and were 

 connected by a layer of neutral sulphate of gallium dissolved in 

 water. This caused, in a fine wire galvanometer, constant de- 

 flections of more than 40°, in a direction showing that the sheet 

 of liquid had negative tension, while the solid plate had positive. 

 This proves the influence of heat of constitution of a simple me- 

 tallic body on the energy of its chemical properties. — On starch, 

 by MM, Musculus and Gruber, They give a list of substances 

 produced at expense of starch under the influence of diastase or 

 diluted and boiling sulphuric acid, — Action of fluoride of boron 

 on certain classes of organic compounds, by M, Landolph. 

 Fluoride of boron combines indefinite proportions, equivalent for 

 equivalent, with aldehydes, with acetones, and with carbonyles. 

 — Researches on the peptones, by M, Henninger. These re» 

 searches seem to indicate that the peptones result from a fixation 

 of water on albuminoid matters, and they thus confirm a hypo- 

 thesis enunciated by M. Dumas more than thirty years ago that 

 pepsine causes the liquefaction of azotised matters by a pheno- 

 menon similar to that of diastase on starch. — Anatomical observa- 

 tions on certain cutaneous excretory glands in the fluviatile 

 tortoises of China, by M, Rathonis. These glands are distinct 

 from those formerly described by Owen and others ; their 

 physiological r6le\% unknown. — Presence and rdle of ammoniacal 

 salts in modern seas, and in the saliferous strata of all ages, by 

 M. Dieulafait. All mineral waters, whether sulphurous or not, 

 whether thermal or not, must contain anomalous quantities of 

 ammoniacal salts. — Experimental proof of the incomplete crossing 

 of the nerve-fibres in the chiasma of the optic nerves ; longi 

 tudinal and median section of the chiasma not followed by 

 blindness, by M, Nicati. 



CONTENTS Pagb 



Tertiary Flora OF North America. By J, S. Gardner F.G.S . 389 



Fouribr's "Analytical Theory OF Heat " jgz 



Our Book Shelf: — 



Topinard's "Anthropology" . . 192 



Smith's " Tailed Amphibians, Including the Caecilians " . -193 



Letters to the Editor :— 



Indian Rainfall. — S. A. Hill 1Q3 



A Twenty Years' Error in the Geography of AustraLa. — Alfred 



R. Wallace 193 



Opening of Museums on Sundays. — Prof, W. T. Thiselton 



Dyer 194 



Socialism in South Africa. — F. E. Colinso 194 



The Telephone Relay or Repeater.— Prjfessors Edwin J. Hous- 

 ton; Elihu Thomson . 194 



New Form of Microphone Receiving-Instrument. — W. J. Millar. 194 



A Waterspout. — E. Wethered 194 



Fortunate " Escape." — Electrified 195 



Velocity of Light. — Albert A. Michelson {With lUiisiratwns) . 195 



University College. — Talfourd Ely, Secretary 195 



Examination of Small Organisms in Water. — Dr. R. E. Dudgeon 196 



The Late Mr. Hewitson 1^6 



Andreas von Ettingshausen 197 



A New Crater on the Lunar Surface 197 



Deep-Sea Dredging off the Gulf of Mexico. By Prof. E. 



Perceval Wright 198 



Meteorological Notes 198 



Our Astronomical Column : — 



The Total Solar Eclipses of May 16, 1882, and August 18, 1887 . 199 



Geographical Notes 200 



The Great Frozen Sea {IVitk lUustratioti) 201 



On the Structure and Develop.me.nt of the Snake, By Prof. 



W. K. Parker, F.R.S. (friVA///?<iifm/7V«.r) 202 



A Fossil Sparrow-Like Bird {XVith Ilhtstratio/ii) 204 



Notes 205. 



The Microphone. By W. H. Prbece, Vice-President S:c. T.E., 



"iA.^m!o.\-!^%\..C.'Sj.,&.c. (With Illustrations) .207 



The Scientific Aims and Achievements of Chemistry. By Prof. 



Aug. Kekul6 210. 



On the Causes of the Ascent of Sap IN Trees 213 



University and Educational Intelligence 214 



Scientific Serials ^'4 



Societies and Academies .,.•...•- 214. 



