148 



NATURE 



\_Dec. 11, 1879 



The maximum number of degrees of freedom which a molecule 

 composed of « smooth rigid spheres could possess would be yi, but 

 the forces in play between the spheres might reduce this number. 

 Thus the value of m + e could not exceed but might be less 

 than Vi + c. When the molecule consists of two atoms e = 

 but for complexer molecules we should, cateru paribus, extract its 

 value to increase with the number of molecules. From two 

 tables of results calculated by him, Prof. Rucker, however, finds 

 that for a number of simple and complex gases and vapours the 

 value of in + e is for each substance less than yi (or the maxi- 

 mum possible value of ;/;), while for the majority of chlorine 

 compounds examined the reverse statement holds good, that is, 

 the value of m + e is generally greater than 3«. This difference 

 may be explained by supposing that for chlorine c is abnormally 

 lar^e, and that the spheres are not necessarily in contact ; or 

 that 11 has been taken too small, that the symbol Cl 2 is incorrect, 

 and that the chlorine atom contains a larger number of sub-atoms 

 than his been ;uppo-ed, a supposition which accords with the 

 recent researches of Prof. Victor Meyer on the vapour density of 

 chlorine. Prof . Rucker also finds that the ratio of the specific 

 heats of bromine and one of its compounds studied (C 2 H„Br), agree 

 with those of chlorine and the corresponding chlorine compounds. 

 Dr. Shettle, of Reading, then read a paper on the influence 

 of heat upon certain forms of induction coils considered more 

 especially in relation to the inductive power which the blood 

 exercises on the various structures of the body. The author 

 found that when a copper and a zinc wire were insulated from 

 each other by parchment paper and paraffined silk, and wound 

 in close proximity to each other, an (induced) current was indi- 

 cated on a galvanometer whose terminals were connected to the 

 neighbouring ends of the zinc and copper wires respectively, the 

 other ends being left free. When the latter were connected 

 across the deflection was nit. On raising the temperature of the 

 two wires by causing hot water to flow inside the coil into which 

 they were wound the deflection was largely increased. The-e 

 experiments lead Dr. Shetile to imagine there is a similar action 

 in the animal body. The heart is made up of nerves and 

 muscular fibres winding spirally, and some of these wind round 

 each other so as to form a spiral cord round which the blood 

 cap-.llaries also wind. Dr. Shettle compares these nerve and 

 muscle bundles to the coils of zinc and copper wire in his 

 experiments, and infers that electric currents may be in- 

 duced in them as in the wires. The flow of the warm 

 magnetic blood would also tend to produce currents in them. 

 Dr. Shettle further drew attention to the fact that animals 

 live and move in a magnetic field, and that electricity must be 

 generated in them by their movements internal and external. — 

 Mr. Emmott exhibited Cros-ley's form of microphone, which 

 consists of four short rods of carbon jointed loosely into four 

 blocks of carbon so as to form a square. It is used as a trans- 

 mitter for telephones, and Mr. Crossley regularly transmits the 

 services of a church with it to several hearers. Its speaking, 

 singing, and whistling powers were successfully demonstrated to 

 the meeting. 



Paris 

 Academy of Sciences, December 1.— M. Daubree in the 

 chair.— The following papers were read :— Observations on M. 

 Tread's last note relative to chlorophyll, by M. Chevreul-. lie 

 asks whether chlorophyll is a constituent part of the organ, or is 

 only accessory and without organic activity. — On some properties 

 of glucoses, by M. Peligot. By action of alkalies on glucose, he 

 obtains a crystalline substance (which he calls saccharine), having 

 the composition of ordinary sugar, or saccharine, not yet sugar. 

 In presence of yea-t it does not ferment ; its taste is not that of 

 sugar, but almost ;;//, with a slight after-bitterness. The common 

 view, that saccharine matters should be regarded as polyatomic 

 alcohols, is not (M. Peligot thinks) confirmed by production of this 

 new substance. In the action of lime on glucose, a true saponifi- 

 cation occurs. — Note on the crystalline form and optical properties 

 of saccharine, by M. Des Cloizeaux. The optical phenomena do 

 not enable one to conclude with certainty whether saccharine 

 belongs to the rhombic or the clinorhombic system.— Questions 

 relative to phylloxera addressed to M. Thenard, by M. Freiny. — 

 Reply to these questions by M. Thenard. This relates to the use 

 of sulphide of carbon, and its effects on vines. — Demonstration, 

 by means of elliptic functions, of a theorem in the theory of the 

 libration of the moon, by M. Gylden.— Note on the measure- 

 ment of quantities of electricity, by M. Ilirn. He calls attention 

 to M. Villari's demonstration that the action of the spark of Ley- 

 den batteries on the magnetic needle is proportional to the quan- 

 tities accumulated, and seeks to show that this law is in harmony 



with those he himself has indicated as to the effect of continuous 

 currents ; (he expresses a wish that M. Yillari's important memoir 

 might be published in cxtenso in French). — Periodic movements 

 of the ground revealed by spirit levels, by M. Plantamour. — 

 This gives results of a year's observations at Secheron from 

 October 1S78. The east side went down with decreasing tem- 

 perature until June, (there being a pretty exact parallelism be- 

 tween the curves) ; then the east rose until the beginning of 

 Scptemb-r, in a much greater proportion than the exterior 

 temperature. From 32'Snvm. the greatest depression to the 

 east, on January 15, to the maximum of elevation 19-5 mm. 

 on September 8 gives 52'3mm. as the total amplitude of oscilla- 

 tion during the year, (or 2S'oSs). There was generally besides 

 a daily movement, with amplitude on September 5, of 3"'2. 

 The minimum is usually between 6 and 7*45 a.m. the maximum 

 twelve hours later. In the meridian direction, the move- 

 ments of the ground are much less ; the total amplitude 

 for the year was only 4"'So. They show an unexplained anomaly 

 relative to the movements east and west. The daily movements 

 in the meridian are very rare, irregular, and small. It seems, 

 then, that at Secheron there are periodic movements of rise and 

 sinking of the ground, and that, generally, they are determined 

 by the exterior temperature. Perhaps the configuration and 

 nature of the ground have also some influence. — Establishment 

 of scientific and hospital stations in Equatorial Africa, by M. 

 de Les-eps. It has been decided by the French Committee of 

 the African Association to establish such stations between 

 Zanzibar and the Gaboon ; the Chambers have voted 100,000 fr. 

 for the purpose. — Astronomical junction of Algeria with Spain ; 

 international operation under General Ibahez and M. Perrier, by 

 the latter. — Note rectificative of M. Viallanes's opinion regarding 

 phylloxeric spots in the environs of Dijon. — M. Lamarre de- 

 scribed an electric phenomenon lately observed by him during a 

 fall of snow at Cherbourg. Luminous aigrettes appeared at the 

 points of his umbrella. — Determination ofcttrves and surfaces of 

 two surfaces which have double or stationary contacts with each 

 other, by M.' Zeuthen. — On series relative to the theory of 

 numbers, by M. Lipschitz". — On a dynamometric brake regulated 

 automatically, by M. Carpentier. — Separation of phosphoric 

 acid from sesquioxide of iron and alumina, by M. Derome. — On 

 the constitution of stag's horn, by M. Bleunard. It is an inferior 

 homologue of coagulated egg-albumen. It is more hydrated than 

 albumen. — Determination of chlorine in different grains and 

 forage plants, by M. Nolte. Chlorides form part of all vegetable 

 food. — Rhythmic contraction of muscles under the influence of 

 salicylic acid, by M. Livon. A rhythmic tetanic period with 

 contractions decreasing in intensity, precedes exhaustion. — On 

 the mode of distribution of phosphates in muscles and tendons, 

 by M. Jolly. — Influence of different colours on the development 

 and respiration of infusoria, by M. Fatigati. The respiration is 

 more active in violet than in white light, and less active in green 

 than in white. 



CONTENTS Page 



Cambridge University i»S 



AUROR.E "7 



Our Book Shelf:— 



Davies's " Treatise on Metalliferous Mines and Mining." — H. B. 129 

 Lettkrs to the Editor : — 



Why the Air at the Equator is not Hotter in January than in July. 



— Jamrs Croll 129 



A Possible Consequence of our Present Weather.— \V. MattieU 



WlILIAMS 130 



The Climate of England.— Alexander Taylor 131 



A Correction.— E. Douglas Archibald 131 



Monkeys in the West Indies.— Edmund Watt 131 



Earthquake in Iceland.— W. G. SrENCE Paterson 132 



D.atoms in London Clay.— W. H. Shrubsole 132 



Colour-Blindness.— John Tennant 132 



Intellect in Brutes.— C. F. Crehore '32 



Electric Lighting.— Albx.S. Gibson '32 



Jean Baptiste AlphonseChevallier T 3 2 



The Sewage of London x 33 



The New Wealden Dinosaur "35 



Cassell's Natural History (With Illustrations) '35 



Prof. Huxley on Technical Education '39 



Notes . x 39 



Our Astronomical Column: — 



Orbits of Binary Stars '4 1 



Errors of the Lunar Tables X 4 X 



Re-discussion of Ancient Solar Eclipses '(' 



The Solar Parallax '4 1 



Meteorolocical Notes 1 4 2 



Geographical Notes • '42 



U.S. National Academy. By Wm. C. Wyckoff '4» 



University and Educational Intelligence T 4» 



Scientific Serials **? 



Societies and Academies '4° 



