Jtme 25, 1874] 



NATURE 



157 



empty as a measure of any permanent dilatation which liolh 

 might sustain by mere lieating and cooling again, a fact \\A\ 

 known to occur. Tlie other sliell, when at a bright red heat, 

 was filled with molten cast-iron and perniitted to cool, its dimen- 

 sions being taken by accurate instruments at intervals of thirty 

 minutes, until it had returned to the temperature of the atmo- 

 sphere (53° F.), when, after applying various coiTections, ren- 

 dered necessary by the somewhat complicated conditions of a 

 spherical mass of cast-iron losing heat from its exterior, it was 

 found that the dimensions of the shell whose interior surface 

 was in perfect contact with tliat of the solid ball which filled it 

 were, within the limit of experimental error, those of the empty 

 shell when that also was cold (53° F.), the proof being conclu- 

 sive that no expansion in volume of the contents of the shell had 

 taken place, which was further corroborated by the fact that the 

 central portion was found much less dense than the exterior, 

 whereas if the cast-iron expanded in consolidating the central 

 portions must be more dense than the exterior. 



It is a fact, notwithstanding what precedes and well known to 

 iron-founders, that certain pieces of cold cast-iron do float on 

 molten cast-iron of the same quality, though they cannot do so 

 through their buoyancy, as various sorts of cast-iron vaiy in 

 specific gravity at 60° F., from nearly 7700 down to 6-300, and 

 vary also in dilatability ; that thus some cast-irons may float or 

 sink in molten cast-iron of different qualities from themselves 

 through buoyancy or negative buoyancy alone ; but where the 

 cold cast-iron floats upon molten cast-ircn of less specific gravity 

 than itself, the author shows that some other force, the nature of 

 which yet remains to be investigated, keeps it floating ; this the 

 author has provisionally called the repellent force, and has 

 -shown that its amount is, itclcris paribus, dependent upon the 

 relation that subsists between the volume and "effective " surface 

 of the floating piece. By " effective " surface is meant all such 

 part of the immersed solid as is in a horizontal plane, or can be 

 reduced to one. The repellent force has also relations to the 

 difference in temperature between tlie solid and the molten metal 

 on which it floats. 



The author then extends his experiments to lead, a metal 

 known to contract greatly in solidifying, and with respect to which 

 there is no suggestion that it expands at the moment of consoli- 

 dation. He finds that pieces of lead having a specific gravity of 

 1 1 '361 and being at 7°° !'"• loat or sink upon molten lead of the 

 same quality, whose calculated specific gravity was U'o7, 

 according to the relation that subsisted between the volume and 

 the " effective " surface of the solid piece, thin pieces with large 

 surface always floating, and viccz'cysa. An explanation is offered 

 of the true cause of tlie ascending and descending currents ob- 

 served in very large "ladles" of liquid cast-iron, as stated by 

 Messrs. Nasmyth and Carpenter. The facts are shown to be in 

 accordance with those above nnentioned, and when rightly inter- 

 preted to be at variance with the views of these authors. 



Lastly, the author proceeds to examine the statements made 

 by these authors, as to the floating ol lumps of solidified iron- 

 furnace slag upon the same when in a molten state ; he examines 

 the conditions of the alleged facts, and refers to his own experi- 

 ments upon the total contraction of such slags, made at Barrow 

 Ironworks, and a full account of which he has given in his paper 

 On the true nature and origin of volcanic heat and energy, 

 printed in Phil. Trans. 1873, as conclusively proving that 

 such slags are not denser in the molten than in the solid state, 

 and that the floating referred to is due to other causes. The 

 author returns thanks to several persons for facilities liberally 

 afforded him in making these experiments. 



Chemical Society, June iS.— Prof. Frankland, F.R.S., 

 vice-president, in the chair. — The following papers were read : — 

 On the action of chlorine, bromine, &c., on isodinapthyl, by 

 W. Smith. — Dr. Armstrong then read four communications 

 from the laboratory of the London Institution, No. XIII. On 

 coal-tar crcsol and some derivatives of paiacresol, by H. Y.. Arm- 

 strong,, and C. L. Field ; No. XIV. On the action of the 

 chlorides of the acids of the sulphur series on organic compounds, 

 by II. E. Armstrong and \V. II. Pike; No. XV. On chloro, 

 Iromo, and iodo-nitrophenolparasulphonic acids, by H. E. 

 Armstrong and F. D. Brown; arrd No. XVI. Note on the 

 decomposition of dichloronitrophenol by heat, by II. E. Arm- 

 strong and F. D. Brown. — The sixth paper was by Mr. F. 

 Neison, On the products of the decomposition of castor oil. 

 No. 111. On decomposition by excess of alkaline hydrate, m 

 which he has succeeded in elucidating the conflicting .statements 

 of different chemists on this subject. — On hydrogen persulphide. 



by Dr. W. Ramsay.— Suberone, by Dr. C. Schorlemmer and 

 Mr. R. S. Dale. — On the action of nitrosyl chloride on 

 organic bodies. Part I.— On phenol, by Dr. W. A. Tilden, 

 — An apparatus for determining the moisture and carbonic 

 anhydride in the atmosphere ; A method for determining ozone 

 in the presence of chlorine and nitric oxide ; and On the consti- 

 tution of urea, by Dr. D. Tommasi. — On the restitution of 

 burnt steel, by Mr. S. L. Davies. — On the action of earth on 

 organic nitrogen, by Mr. E. C. Stanford. — Aniline and its 

 homologues in coal-tar oils, by Mr. W. Smith. 



Zoological Society, June 16.— Dr. A. Giinther, vice- 

 president, in the chair.— An extract was read from a letter 

 received from Dr. A. B. Meyer, concerning two birds (Redes 

 benndli and Camftp/iaga aurulenta) lately described in the 

 Society's Proceedings by Mr. Sclater. — A letter was read 

 from Mr. William Summerhayes, relating to certain species of 

 Curassows found in Venezuela. — Dr. J. Murie read a paper on 

 the nature of the sacs vomited by the Hornbills, which he stated, 

 in confirmation of Prof. Flower's account of these objects, to 

 consist of the epithelial lining of the stomach. — Mr. W. Saville 

 Kent, F.L.S., commrrnicated a second paper upon the gigantic 

 cephalopods recently encountered off Newfoundland. From 

 further information received, Mr. Saville Kent apprehended that 

 it would be necessary to refer the two individuals preserved in 

 St. John's Museum to the genus Omiimlos/rep/ws, thus avoiding 

 the institution of a new genus for their reception, as proposed in 

 his former paper.— Mr. A. H. Garrod read a paper on the 

 ".showing off" of the Australi.an Bustard {Eupcdclis australis) 

 and pointed out the peculiar structures by which this " showing 

 off" was accomplished. — A communication was read from 

 Dr. F. Stolicza, containing a description of the Ovis foUi 

 of Blyth, of which he had lately obtained specimens in 

 Yarkand. — Mr. R. B. Sharpe read a paper on a new genus 

 and species of Passerine birds from the West Indies, which he 

 proposed to name Plia-niconiancs ima. — A communication wes 

 read from the Rev. O. P. Cambridge, containing descriptions of 

 some new species of Spiders of the genus Erigone from North 

 America. — Dr. Giinther read a paper descrrbing some new 

 species of reptiles from the Camaroon Mountains, West Africa. 

 Amongst these were two new species of Chameleon, and a new 

 snake of the family of Lycodontida:, proposed to be called 

 BotJijolyciis alcy. Orre of these Chameleons was referred to a 

 new subgenus (Rhamplwleon), being remarkable for its abbreviated 

 tail and the development of a denticle at the inner base of each 

 claw. — Mr. Sclater read a paper containing a description of three 

 new species of the genus Synalla.xis from M. Jelskr's coUectioiis 

 in Central Peru, which he proposed to call S. Piidibiinda, 

 S. grainiiiicola, and .J. virgala. — Messrs. H. P. Blackmore and 

 E. R. Alston communicated a joint paper on the , Arvicolida; 

 which have hitherto been found in a fossil stale.— Prof. Newton 

 read an account of a living Dodo shipped for England irr the year 

 1628, extracted from letters in the pos.session of Dr. J. B. 

 Wihnot, of Tunbridge Wells. — Mr-. J. E. Harting r-ead a paper 

 on the common Lapwing of Chili, which he proposed to separate 

 from VaiicUiis cayaneitsus, under the name \'. oceidciitaPis. — A 

 second paper read by Mr-. Harting contained an account of the 

 eggs of some new or little-known Limicola>. — A communication 

 was read from Mr. R. Swinhoe containing an account of a new 

 Cervine form discovered in the mountains near Ningpo, China, 

 by Mr. A. Michie, and proposed to be called Lophctragus 

 nilcttianiis. — Dr. J. Murie read a paper on the structure of the 

 skeleton of Fregilupus varius, based on a specimen in the Museum 

 of Cambridge. 



Meteorological Society, June r7. — Dr. R. J. Mann, pre- 

 sident, in the chair. — On the connection between colliery explo* 

 sions and weather in the year 1S72, by Robert H. Scott, F.R.S., 

 aird W. G.alloway, Inspector of Mines. The paper is in con- 

 tinuation of those by tire same authors read before the Royal 

 •Society in 1872, and before the Meteorological Society in 1S73, 

 which contained the results for the four preceding years. The 

 number ot fatal explosions which occurred during the year. was 

 70, causing the loss of 163 lives. Three of these killed each of 

 them more than ten men, being the same as the average number 

 of serious explosions for the last twenty years. The number of 

 non-fatal explosions was 224. A comparison of the dates of all 

 recorded explosions with the curves of the barometer and ther- 

 mometer kept at Stonyhurst for the Meteorological Office, as 

 shown on a diagram, lead to the following results : — 58 per cent, 

 of the explosions are due to changes of pressure, 17 per cent, to 

 great heat of the weather, while 25 per cent, are not attributed 



