Jl/arc/i 25, 1880] 



NATURE 



507 



or volts. Taking the formula J - 



-, where y is Joules's 



(// + ") X 



equivalent, //is the heat actively evolved, n the heat evolved by 

 roc imposition, and x a constant to which Kohlrausch gives the 

 value of "000105, Dr. Wright finds that Joules's equivalent 

 should be 4M96 X io 7 , instead of 4'20 X io 7 , as given, to answer 

 the formula. The author thinks that Joules's water-friction 

 experiment- L'ave the truest value of y, and that his electric 

 heating experiments gave a result about A per cent, too low, 

 owing to the U.A. unit of resistance being about 2 per cent, too 

 high and other causes. 



Chemical Society, March iS. — Mr. Warren De la Rue, 

 president, in the chair. — Prof. Tidy read a paper of over ico 

 River-water. He discussed the subject under three 

 heads:— I. Analytical details of river-waters. 2. The various 

 sources of impurity to which river-water is subject, and the 

 means whereby \ u ity is maintained by nature or may be effected 

 by art. 3. The extent to which statistics warrant us in con- 

 demning or in approving the supply of river-water for drinking- 

 purposes. Under the first head the author gives detailed analyses 

 of water from the Thames from 1876-1S79; analyses are also 

 given of water from the rivers Nile, Severn, and Shannon. 

 Under the second head is discussed the effect (1) of flood-water, 

 which at first deteriorates and then improves the quality of river- 

 water ; (2) of peat, the quantity of which in a water is kept in 

 check by "a," the inherent power that water possesses of self- 

 purification, owing to the oxidation of the peat by the oxygen 

 held in soluti n in the water, and "b," mechanical precipitation 

 by admixture with coarse mineral matter suspended in the water; 

 (3) f sew aye matter. This, in the opinion of the author, is a 

 most vital que-tion. From inspection of the effect produced by 

 sewage on rivers, from analyses of the river-waters, and from 

 experiment, the author concludes that the oxidation of the 

 organic mat er of sewage takes place, when mixed with un- 

 polluted water and allowed a certain flow, with extreme rapidity. 

 The various methods of artificial purification are discu-sed ; of 

 these filtration through sand is preferred. Under the third cate- 

 gory the arguments for and against the use of river-water for 

 Irinking-purposes are examined : it is show n that the dea'h-rates 

 of towns supplied by wells and of th se supplied by rivers are 

 practically alike, and that in London there is very little "to 

 choose, as regards mortality, between districts supplied with 

 well-water and those supplied by river-water ; and while admit- 

 ting that, as a mitter of sentiment, he would prefer well-water, 

 the aulh ir contends that there is no reason for supposing that 

 the materia morbi, whether it exits as a germ or not, can resist 

 oxiilati in, which is efficient in destroying other organic matter, 

 as proved by chemical analysis. The author finally submits the 

 two following conclusions : — I. That when sewage is discharged 

 into running water, provided the dilution with pure water be 

 sufficient, the whole of it, after the run of a few miles, will be 

 efficiently got rid of. 2. That facts indicate that whatever 

 may be the actual cause of certain diseases, the materia morbi 

 which finds its way into the river is destroyed along with the 

 organic impurity. 



Meteorological Society, March 17. — Mr. G. J. Symons 

 F.R.S., president, in the chair. — Sir A. F. Bruce Chichester, 

 Bart., W, II. Cochrane, Rev. H. Garrett, M.A., II. Jonas, J. 

 I.ingwood, Lieut. -Col. L. W. Longstaff, Rev. C. E. Sherard, 

 T. II, Stewart, and Dr. W. J. Treutler were elected Fell iws of 

 the S 11 iety. — The following papers were read : — Thermometric 

 observati ins on board the Cunard R.M.S.S. Algeria, by Capt, 

 William Wat-on, F.M.S. — On the Greenwich sunshine records, 

 1876 80, by William Ellis, F. R.A.S. — At 8 p.m. the discussion 

 was suspended in order to afford the fellows an opportunity of 

 a lar^e number of new and interesting meteorological 

 ich had been brought together for exhibition. 



Entomological Society, March 3. — H. T. Stainton, F.R.S., 

 &c, vice-president, in the chair. — Dr. Ily. (.has. Lang, of 41, 

 Street, and Mr. Frank Crosbie, of Baraet, were elected 

 Ordinary Members of the Society. — Mr. Pascoe exhibited several 

 species of scorpions in reference to a statement recemly made 

 that scorpions had been known to sting themselves to 

 death when surrounded by fire. This. Mr. Pascoe doubted, and 

 sh iwed that the two common Europeans ecies, Scorpio curofxrut 

 and Buthus occitans were almost physically inca; able of effecting 

 such a purpose. — Mr. Stevens exhibited a dwarfed female speci- 

 men of Plcbius icarus \Lycana alexis). — '1 he Rev. A. E. Eaton 

 exhibited several plates of drawings of Ephemerida, part of a 



forthcoming work, and contributed remarks thereon. — The 

 Secretary exhibited, on behalf of Mr. Geo. Francis, of Adelaide, 

 the microscopical specimens referred to at the last meeting of the 

 Society.— Mr. Howard Vaughan exhibited a series of Cidaria 

 russata from Yorkshire and the Isle of Arran, in illustration of 

 local variation of the species. — The Rev. H. S. Gorham read a 

 further communication on the LampyrUee, and also a paper 

 giving the result of his observations on these insects with respect 

 to their phosphore-cence, which he believed to be due to sexual 

 causes. With regard to the typical species of the family, he 

 observed that in the most highly organised genera, such as 

 Lamprocera and CtaJodcs, the light-emitting faculty did not 

 appear to be developed in proportion with the rest of the organs, 

 and that the eyes w ere also reduced "in a direct ratio with the 

 light," being small and uniform in both sexes, "whilst the 

 antenna- were developed in an inverse ratio as the phosphor- 

 escence was diminished." — Mr. C. M. Wakefield communicated 

 a paper by Mr. Fereday containing descriptions of new species 

 of the family Lucanidce and the genus Chlenius. — The following 

 papers were also communicated : — On synonyms of heterocerous 

 lepidoptera, by Mr. Butler ; and descriptions of Cetoniidas and 

 Cerambycidae, from Madagascar, by Mr. Waterhouse. 



Photographic Society, March 9. — James Glaisher, F.R.S., 

 president, in the chair. — A paper was read by the Rev. H. 

 1 ansdell, F. R.G.S., on a tour round the wc rid, via Siberia and 

 California, from which it appeared that photography in Russia 

 and Siberia, in relation to its art-element, is in a very advanced 

 condition. Some very interesting pictures of the eastern tribes 

 of Russia and Siberia, bordering on China were shown, and also 

 of the entire route, covering 25,510 miles. — A paper was also 

 read by Capt. Abney, R.E., F.R.S., on the lateral spread of 

 the image during alkaline development, showing that there was 

 a travelling outwards of the deposit by alkaline development 

 from the nucleus which forms the undeveloped image ; this takes 

 place in all directions, but when spreading laterally, it caused a 

 blurring of the outline, seen in gelatine emulsion plates. 



Institution of Civil Engineers, March 9. — Mr. W. H. 

 Barlow, I. K.S., president, in the chair. — The paper read was 

 on the purification of gas, by Mr. Harry Edward Jones, 

 M.Inst.C.E. 



Statistical Society, March 16. — Sir Rawson W. Rawson, 

 C.B., K.C.M.G., in the chair. — Two papers were read, the first 

 by I>r. T. Graham Balfour, F.R.S., on vital statistics of cavalry 

 horses. — The second paper, read by Prof. Leone Levi, LL.D., 

 was entitlol a survey of indictable and summary jurisdiction 

 offence in England and Wales, from 1857 to 1878, showing that 

 the last twenty-two years have been on the whole favourable to 

 the economic condition of the people, and the leading operating 

 causes of crime have been less intense than in former years. 



Dublin 

 Royal Dublin Society, February 16. — Physical and Experi- 

 mental Science Section. — Wentworth Erck, LL. D., in the chair.- 

 Physical observations of Mars, I S79-80, by Charles E. Burton, 

 F. R.A.S. 22 sketches of the planet were obtained under favourable 

 circumstance-. To these Mr. Dreyer, of the Dunsink Observatory, 

 added two, taken by himself with the "South" equator : 1. The 

 whole series, beside- supporting the hypothesis that the principal 

 are permanent as regards form and position, generally 

 confirms the existence of the "canals" of Schiaparelii, adding 

 perhap- a ew which appear to have been detected fir the first 

 time in 1879, though it is not asserted that they are newly 

 formed. The author's impression, from observation and com- 

 parison with earlier results, is that no rapid surface changes are 

 now proceeding on Mars, and the great changes of appearance 

 are due to formati >n and disappearance of cloud or mist in the 

 planet's atmo phere. A numberof areograpic positions of spi ts, 

 determined by Kaiser's method, with the help of Marth's 

 ephemeris, are included in the paper. The analogy bttween 

 Mars and the eai th is seemingly weakened by recent observations. 

 — Notes from the Physical Laboratory of the Royal College of 

 Science, by Prof. W. F. Barrett: — I. On the cause of the 

 vibration in the Trevelyan rocker. The author attributes the 

 ,! the force exerted by a thin layer of gas between the 



1 support. As long as there is sufficient 

 ditlercncc of temperature between the two surfaces, the support- 

 ing edges of the rocker are alternately repelled from the cool 



