48 



NATURE 



\_May 8, 1879 



netic core of the instrument. Prof. Thomson applied his 

 method of getting magnetic curves with iron filings dusted on 

 gummed glass to this problem. He found that when no currents 

 pasted in the telephone the magnetic lines springing from the 

 pole of the magnet are gathered together on the diaphragm 

 opposite over a central region, which is magnetised lamellarly or 

 like a magnetic shell. The rim of the plate beyond this region 

 is, however, magnetised radially, and between these two zones 

 there is a neutral circle. It was remarkable too that the lines of 

 force touching the plate were bent back around this circle, form- 

 ing a kind of valley. When the current passed in the coil, in 

 a direction so as to reinforce the magnetism, the lines are gathered 

 more closely on the central region of the plate. If the current 

 diminishes the magnetism the lines are, on the other hand, 

 repelled from ihe plate. The neutral ring is also altered. In 

 the first case it shrinks in size, in the second it expands. A 

 small thick disk is wholly magnetised lamellarly ; a disk entirely 

 magnetised radially becomes slightly conical in shape. In the actual 

 telephone the disk is flat at the middle and conical at the edges. As 

 the current varies the diaphragm will assume new nodal lines. 

 Dr. Thompson concludes that the molecular theory is not there- 

 fore necessary to account for the speech of the telephone, 

 although it may assist. As confirming this view, he found that 

 with iron rings round a cardboard diaphragm, and an iron centre- 

 piece, the enunciation was good, though the timbre was altered, 

 whereas w ith radial pieces of iron on the cardboard, the timbre 

 was good but the enunciation bad. In reply to Prof. Adams, 

 Dr. Thompson said that the stronger the magnet the shorter the 

 lamellarly magnetised space became, and that with a thicker 

 disk the neutral ring was not so well marked. Dr. Lodge sug- 

 gested that the best place for the coil would be in the valley over 

 the neutral ring, which was in an unstable condition. Dr. 

 Thompson next wrote on a saw-blade with a magnet and dusted 

 iron filings on it, which arranged themselves so as to trace the 

 writing. This is usually shown on a steel plate, but a saw re- 

 tains the virtue for six or eight months. A modification of this 

 experiment, due to himself, consisted in writing on the blade 

 with one pole of a powerful battery, the other pole being con- 

 nected to the end of the blade. The third "note" recom- 

 mended the use of fine steel fibres, got by breaking iron gauze 

 of 32 meshes to the inch, instead of iron filings, for exhibiting 

 magnetic lines. The fourth note showed that the lines of force 

 got by filings fixed on cards are magnetic, that of a bar-magnet 

 acting as a magnet. The fifth note explained that solid mag- 

 netic " figures " could be got by coating iron filings in shellac 

 to make them light, and floating them in water ; or by mixing 

 filings in a soft paste of plaster of Paris, which could be cut into 

 sections on hardening. 



Chemical Society, May l. — Dr. Warren de la Rue, presi- 

 dent, in the chair. — The following papers were read : — On the 

 volumes of liquids at their boiling-points obtainable from unit 

 volumes of their gases, by Dr. W: Ramsay. The author has 

 suggested the use of a thin glass bulb filled with the liquid, and 

 heated in its own vapour until expansion ceases, the bulb is then 

 allowed to cool, and is weighed ; thus the volumes of many 

 liquids at their boiling-points, "ebullition volumes," has been 

 determined by the author. His results agree closely with those 

 obtained by Kopp ; the time required for a determination is 

 half an hour. — On a method of precipitating manganese as di- 

 oxide, and its application to the volumetric determination of man- 

 ganese, by J. Pattinson. Manganese in solution can be com- 

 pletely precipitated as dioxide by bleaching-powder solution or 

 bromine water, if an equal quantity of iron, as ferric chloride, 

 be present. The dioxide is then dissolved in dilute sulphuric 

 acid, reduced by standard ferrous sulphate and titrated with 

 bichromate. — On the determination of nitric acid as nitric oxide 

 by means of its action on mercury, by R. Warington. In this 

 well-known process of Crum and Frankland the author has 

 found that the removal of the chlorides is unnecessary, and that 

 small quantities of organic matter, except cane sugar, do not 

 interfere with the results. — On a new class of colouiing-raatters, 

 by Dr. O. N. Witt. By oxidising a mixture of metatoluylene 

 diamine and dimethylparaphenylendiamin in aqueous solution, 

 the author has obtained several new colouring-matters, toluylen 

 blue, violet, pink, &c. 



Institution of Civil Engineers, April 29. — Mr. Bateman, 

 F.R.S., president, in the chair. — The first paper read was on 

 street carriageway pavements, by Mr. George F. Deacon, 

 M._Inst. C.E, — The second paper read was on wood as a- paving 



material under heavy traffic, by Mr. O. H. Howorth, Assoc. 

 Inst. C.E. 



Edinburgh 



Royal Society, April 21. — On the anatomy of the northern 

 Beluga {B. catodon) compared with that of other whales, by 

 Morrison Watson, M.D., ar,d Alfred H. Young, M.B., of the 

 Owens College, Manchester. — This paper contains a complete 

 account of the visceral anatomy of Beluja. In connection with 

 the larynx, the existence of pouches similar to those previously 

 described by Murie in Risso's Grampus is pointed out. These 

 pouches undoubtedly conespond to the large laryngeal air-sac 

 of the whaletione whales ; both are regarded by the authors as 

 homologous with the ventricles of Morgagni of other mammals, 

 and not, as considered by previous anatomists, with ihe well- 

 marked air-sacs met with in several species of quadrumana. 



Boston, U.S.A. 



American Academy of Arts and Sciences, April 9. — 

 Hon. Charles Francis Adams in the chair. — Prof. Benjamin 

 Peirce presented a paper on the meteoric constitution of the solar 

 .system, in which the existence of a meteoric shell outside of the 

 planetary system is maintained. The meteors, in falling from 

 this shell, would be subject only to the attractions of the sun 

 and planets. The motions of the larger meteors or comets were 

 discussed, and some remarkable agreements of observed facts 

 with the theory were shown. — Prof. Pickering described a new 

 form of transit instrument for measuring the light of the stars. 

 Much of the time spent when using other photometers in identi- 

 fying the object is thus saved. The stars are compared directly 

 with the pole-star, and the variations of an artificial star are thus 

 avoided. At the Harvard College Observatory the measurement 

 of the light of about 4,000 stars of the sixth magnitude and 

 highest, has been undertaken with this instrument. Each star 

 will be observed on three nights, and two sittings will be made 

 each evening. — A paper on the action of bromine on substituted 

 toluols was pre-ented by Prof. C. Loring Jackson and Mr. A. 

 W. Fields. — Mr. W. W. Jacques, of Johns Hopkins University, 

 Baltimore, presented the results of an investigation into the dis- 

 tribution of heat in the spectra of various sources of radiation. 

 The distribution of heat in the spectrum of a solid or liquid 

 source of radiation was found to be nearly independent of the 

 temperature of the source. Dr. Draper's conclusion that "It 

 necessarily follows that in the spectrum any two equivalent series 

 of undulations will have the same heating power, no matter 

 what their actual wave-length maybe," was found to be not 

 correct. 



CONTENTS Pag. 



The Chemistry of Common Life 25 



SlLUKlAN Fossils ^^ 



Our Book Shelf;— 



"Natural History Rambles** :'7 



Letters TO ihk Editor:^ 



Brorsen's Comet.— Capt. G. L. TuPMAM; WiLLiAW Marshall 



Watts ; T. W. Backhouse ^8 



Temperature Equilibrium in the Universe in Relation to the 



KineticTheory.—S. Tolver Preston S 



Barometric Pressure and Sun-Spots.— E. DotrcLAS Archibald . . j3 



Distribution of the Mack Rat.-— Dr. A. B. Meyer 29 



Mice and Beetles.— W. WoRBV Beaijmont 29 



The Cause of Thunder.— S. A. R 39 



The April Meteors— W. F. Denning . 29 



Salmo salar and the Schoodic Salmon. — Chas. G. Atkins ... 29' 



Intellect in Brutes — W. D. GONNING ^9 



On the Evolution of the Vertebrata. By Prof. Parker, F.R.S. 



I^With Illustration) Jo 



The Newest txpLOsivE. By H. Baden Pritchard 3a 



The British Museum Library 33 



On the Figure of the Earth. By J. Heeschel 33 



The Royal Society Soiree 35, 



A New Calendar Clock (;f7//4 ///«j/nj<io») 35 



Spiral Sliue Rule (With Illustration) 36 



OoR Astronomical Column: — 



A New Nebula 3^ 



Brorsen's Ci met • • 37 



Re-observation of Tempel's Comet, 1867 II 37 



Gbogkaphical Notes 37 



Trenham Rpeks J" 



William Geokge Valentin 39 



Electkic Lighting 39 



Notes 3^ 



Recent Contributions to the History of Detomatiho Agents, 



II. ByProf. Abel, C.B., F.R.S ■«» 



Notes from Russia. By A. Lohonossoff 45 



University and Euucational Intelligencr 45 



Scientific M'.f'iAus •• 45 



Societies and Acadbmirs ^* 



