June 5, 1895] 



NATURE 



143 



venting the separation of the components when the volume was 

 nltered, and he could, therefore, thoroughly appreciate the 

 iitility of the author's device for overcoming this difficulty. They 

 liad also experienced considerable difticully in filling the tube 

 uith a mixture of known composition and free from air, and he 

 ■ msidered that when dealing with mixtures it was better to 

 employ gases, although they could not be obt,iined in so perfect 

 a state of purity as liquids, on account of the greater ease with 

 ■which a mixture of known composition can be obtained. The 

 plan of making separate observations on the jiure substances was 

 a good one, and considering that the author measures the 

 increase of pressure during the process of condensation, so that 

 any air which happened to be present produced the maximum 

 effect, the small rise in pressure obtained indicated a high degree 

 of purity in the gases employed. He would like to ask the 

 author if in the case of mixtures he found it possible to 

 determine accurately the point where condensation commenced 

 antl ended, for with the alcohol and ether mixtures 

 they had found it very difficult to determine these 

 points. He also hoped the author would continue his obser\'- 

 ations in the direction indicated in the |)aper. Mr. Inwards 

 suggested that in the case u{ liquids which act on iron, the iron 

 stirrer could be enclosed in glass or india-rubber. It might also 

 be pos.sible to obtain more efticient stirring by means of a small 

 fan or pro[)eller worked by an electro-magnet rotating outside 

 the tube. The author, in his reply, said that when the 

 mixtures were well stirred, the pressures at which condensation 

 commenced and en<led were well marked. — Mr. Burstall com- 

 menced the reading of a paper on the measurement of a cyclic- 

 ally varying temperature. The experiments were undertaken 

 with a view of measuring the temperature inside the cylinder of 

 a gas engine at different points of the stroke of the piston. .V 

 m<xlified form of platinum thermometer is employed to measure 

 the temperature, and since the variations in temperature are 

 extremely rapid, the wire had to be very thin and unprotected 

 1)y any covering such as is ordinarily employed. The leads of 

 the thermometer [Mss through a slate plug fixed in a seamless 

 steel tube, asl>estos being used as a packing to prevent leakage. 

 The resistance of the thermometer is mea-sured by means of a 

 Wheatstone's bridge. .Since the temperature at a certain part 

 •only of the Kwr/'f//^ stroke had to be measured, the galvanometer 

 ■circuit was broken in two jilaces ; one of these breaks was closed 

 by means of a cam on the shaft of the engine at a given fxiint of 

 each revolution, while the other was closed when an explosion 

 took place by means of a relay worked by the ]K)interf)f a steam 

 •engine indicator att.iched to the cylinder of the engine. The 

 Temainiler of the paper was postponed till the next meeting. 



Linnean Society, May 24. — .Xnniversary Meeting —Mr. 

 C B. Clarke, President, in the chair. — The Treasurer presented 

 his annual reiJort, duly audited, and the Secretary having 

 announced the elections and deaths during the past twelve 

 months, the usual ballot took place for new members of Council. 

 The following were elected : — Prof J. B. farmer, Mr. .\. (iepj). 

 Prof Howes, Dr. Si. (1. .Mivart, and .Mr. .\. S. Woodward. 

 On a ballot taking place for the election of President and officers, 

 Mr. Charles Baron Clarke was re-elected President, Mr. Krank 

 Oisp Treasurer. Mr. B. I). Jackson Botanical Secretary, and 

 Prof (i. H. Howes Zooli^ical .Secretary. The Librarian's 

 re|)ori having been read, anil certain formal business dis|X)sed 

 ■of, the President delivered his annu.al address, prefaced by some 

 remarks on the present position of the Society. On the motion 

 of Sir Joseph Hooker, seconded by I'r. John .\nders<m, a vole 

 of thanks was accorded to the President, with a reipiest that he 

 would allow his address to be printed. The .Society's gold 

 medal was then formally awarded to Prof Ferdinand Cohn, of 

 Breslau, and was received on his behalf by .Mr. B. I). Jackson for 

 transmission through the Herman emba.ssy. The President 

 ■having called attention to the retirement of the Zoological Secre- 

 tary, Mr. \V. Percy Sladen, after holding office for ten years, an 

 announcement which he felt sure would lie received with uni- 

 versal regret, it was jiroposed by Mr. Carruthers, seconded by 

 Mr. Crisp, and supported by Mr. Charles Breese— "That the 

 I'ellows of this Society, regretting the retirement of Mr. Walter 

 Percy Slailen fr<un the post of Zoological Secretar)', which he 

 has occupieil for the |)ast ten years, desire to record upon 

 the Minutes of the Society an ex|>ression of their high 

 appreciation of the services which he has rendered to the 

 .Society, and of the very able manner in which he has at all times 

 discharged the duties of his office. " This resolution having lieen 

 put, was carried unanimously, and after a sympathetic reply 



NO. 1336, VOL. 52] 



I from Mr. Sladen, the Society adjourned to June 6. In the 

 ' evening a number of Fellows of the Society dined together at 

 the Grand Hotel, Charing Cross, the President occupying the 

 chair, and being supported by several distinguished visitors. 



Royal Meteorological Society, May 15. — Mr. R. Inwards, 

 President, in the chair. — .Mr. (j. J. Symons, V'.K.S., and Mr. 

 G. Chatterton read a paper on the November floods of 1894 in 

 the Thames Valley, which they had prepared at the request of 

 j the Council of the Royal .Meteorological Society. This con- 

 ' sisted of a systematic description of the cause> which led to the 

 , great floods of November last, and an analysis of the records 

 ■ obtained from the Thames Conservancy Board, from the engineers 

 of several of the towns along the river, and also from rainfall 

 observers throughout the Thames watershed. The information 

 1 was given chiefly in the form of tables, one of the first being a 

 I chronological history of floods in the Thames \ alley from the 

 ! year 9 A. i». down to the present time. This was followed by a 

 short description of the damage wrought in November 1894, 

 which was illustrated by a number of interesting lantern slides. 

 Details were then given of the levels reached at various places 

 in all the principal floods from 1 750 to the present time. The 

 authors exhibited a map showing the relative elevation of all the 

 parts of the Thames basin, and then gave details of the rainfall 

 for each day from October 23 to November iS. 1894. The 

 results obtained by the Thames Conservancy Board, showing 

 the flood levels at each lock, were exhibited on a longitudinal 

 section from Lechlade to Teddington, and the hydraulic inclina- 

 tions from lock to lock were shown in a tabular form. The 

 volume of flood water, as gauged by the Thames Conser\-ancy 

 at Teddington, rose rapidly from 4000 million gallons per diem 

 on November 12, \^.^ 10,250 million gallons on the l6lh, 12,800 

 million gallons on the 17th. and to over 20.000 million gallons 

 on the iSth, when the discharge reached its maximum. The 

 la.st-named tlischarge is equivalent to 0"37 inch over the whole 

 watershed of the Thames .above Teddington Lock. — Mr. F.J. 

 Brodie read a short paper on the barometrical changes pre- 

 ceding and accompan)'ing the heavy rainfall of Nfivember 1894, 

 from which it appeared that the latter half of October was 

 characterised by unusually bad weather, especially in the more 

 western and southern parts of the Briti-sh Isles. The torrential 

 rains from November 11 to 14, which actually caused the floods, 

 were due to two secondary depressions which developed a 

 certain anirmnl of intensity as they passed over the southern pan 

 of England. 



Cambkidc;e. 



Philosophical Society, May 13. — Prof J. J. Thomson, 

 President, in the chair. — Exhibition of some recent photographs 

 of the moon, by Mr. Newall. — On the "volume heat'' of 

 aniline, by Mr. E. H. Griftiihs. The results of an inquiry (by 

 what may be termed an absolute method) into the influence of 

 temjierature on the caiiacity for heat of aniline were published 

 in the Philosophical Maga-ine, Januarj- 1S95. During last 

 autumn, Mr. C. (Ireen, of Sydney College, made a series of 

 observations on the density of the same com|Miund, over the 

 temperature range 15° to 52' C. Three separate sets of deter- 

 minations of the density gave very concordant results. If the 

 capacity for heat of equal volumes at different temperatures Ix: 

 denoted by the phrase " voUtmc heat^^ then the " \olumeheat" 

 at any tem|)erature is the product of the capacity for heat and 

 the density. In the case of aniline, the " volume heat " appears 

 to t)e constant. Our knowledge Of the change.-- in the capacity 

 for heat of water due to changes of temperature is m> uncertain 

 that the ntativc values of the changes in the sjiecihc heat of 

 other substances are of little absolute value. The author, there- 

 fore, has been unable to exlenil the inquir)- into the " volume 

 heat " of other bodies than aniline, for he has not .succeeded in 

 finding any other determinations which do not rest on some 

 a.ssumption as to the behaviour of water. — Kxhibiiion of Gold- 

 stein's experiments on kathtnle rays, by Mr. J. W. Capstick. 

 Mr. Capstick showed ( loldstein's experiments on the effect of a 

 stream of kathode rays on salts of the alkalies. When the rays 

 are directed on pot.as.sium chloride, for instance, the salt becomes 

 of a heliotrope colour, and retains the colour for several days if 

 kept out of contact with moisture. The eti'ect api>ears to be 

 due to a chemical change in the substance — proliably the forma- 

 tion of a sub-chloride — hut the Layer of altered salt is so exceed- 

 ingly thin that it is difiticult to get unequivocal chemical evidence 

 as to its nature. — On a curious dvnamical property of celts, by 

 .Mr. C;. T. Walker. Mr. G. T. W.ilker exhibiio.l , elt-; which 



