462 



NATURE 



{Sept. 15, 1 88 1 



expediency of continuing the work of the Association, if 

 it keep at all near to the standard of the York meeting. 

 The German Society, founded nine years before our 

 .' ssociation, and its prototype, still continues to meet 

 annually ; and scientific congresses are becoming more 

 and more general every year in Europe. 



Canada has been proposed as the place of meeting 

 for 1885. The difficulties of time and place and e.x- 

 pense are far less formidable than they appear at the 

 outset. Great facilities would be put in our way by 

 steamboat companies ; and, once arrived, the Colony 

 would receive us with open arms. -A-gain, the Ame- 

 ricans wish us to join their Association on some con- 

 venient occasion, and apropos oi this a practical .\me- 

 rican observed a few diys since, "From the moment 

 you set foot on American soil to the moment of de- 

 parture, you should not put down a cent." One 

 other fact remains to be noticed in regard to the York 

 meeting. Thirty-four local societies and institutions 

 were represented at the meeting by forty-nine delegates ; 

 and the Council have under consideration the conditions 

 under which these delegates were present, and their 

 object in attending. Cannot the Association do some- 

 thing for them ? Cannot some organisation be introduced 

 to influence the local societies through the .^.ssociation, 

 and cannot a co.nmittee of delegates be appointed to 

 discuss matters connected with their respective institu- 

 tions ? 



REPORTS 



Report of the Committee, consisting of Dr. J. H. Gladstone'' 

 Dr. IV. R. E. Hod^kinson, Mr. W. Carleton William!, and 

 Dr. P. P. Baison (secretary), appointed for the purpose of inves- 

 tigating the Method of Determining tlie Specific Refraction of 

 S Aids from their Solutions. — Mr. P. P. Bedson, D.Sc, read the 

 Report, and stated that the object of this report was to .Mibniit to 

 further examination the method proposed some years ago by 

 Messrs. Glad^tone and Dale. According to this method the 

 specific refraction of a solid may be deduced from that of a 

 solution containing it, provided the specific refraction of the 

 solvent is known, as also that of the solution and the composition 

 of the solution. The experiments, of which an account is given 

 in the report, appear to confirm this statement of tlie above- 

 mentioned authors. The first case examined was that of liquid 

 phenol. Its specific refraction for a ray of light of infinite wave- 

 length was determined at 40° and 45°. The values obtained for 

 the specific refraction of liquid phenol at 40° and 45°, vi^., '4850 

 and '4848, are closely approximate to that obtained l>y Briihl 

 {Journ. Chem. Soc, ab-t., 1880, p. 782) for phenol at 20°, viz., 

 •4862. Further, these re-ults agree very well with the mean of 

 the specific refractions obtained from the alcoholic and acetic 

 acids solution;. The specific refraction of rock-salt in the solid 

 state has also been determined and compared, with it^ specific 

 refraction as deduced from its aqueous solutions ; and it was 

 found that the specific refraction obtained from the aque iu ; 

 solution is substantially the same as that obtained from a prism 

 of rock-salt. Further, the specific refractions of fu^ed borax 

 and boric acid have been determined, and in these cases abo the 

 specific refraction obtained from their aqueous solution; was 

 found to be approximately the same as the specific refractions of 

 fused borax and boric acid. The indices of fused borax and of 

 fused boric acid were determined by means of prisms of these 

 materials, which were cast in a mould of silver plates and after- 

 wards ground and poli-hed. 



Report of Committee on Meteoric Dust, by Prof. Schuster. — 

 This Cojumittee was appointed for the double purpose of exa- 

 mining thj observations hitherto recorded on the subject of 

 meteoric dust and of discussing the pjssibjlity of futuie more 

 systematic investigations. With regard to the first point we n ite 

 that in a paper presented to the Royal Astronoaiical Society in 

 1S79, Mr. Raiyard has given what appears to be a pretty com- 

 plete account of the known observations as to the presence of 

 meteoric dust in the atmosphere. It appears that in the year 

 •852 Prof, Andrews found native ir.m in the basalt of the 

 Giant's Causeway. Nurdenskjold found particles of iron wliich 

 in all probability had a cosmic origin in the snows of Finland 

 andintheice-fieldio'' the Arctic regions. Dr. T. L. Phipson, and 

 more recently Tissandier, found iundar particles depo.ited by 



the winds on plates exposed in different localities. Finally, Mr. 

 J(jhn Murray discovered mignetic particles raised from deposits 

 at t'le bottom of the sea by H.M.S. Challenger. These particles 

 were examined by Prof. Alexander Herschel, who agreed with 

 Mr. Murray in ascribing a cosmic origin to them. For fuller 

 details and all references we must refer to Mr. Ranyard's paper. 

 There cannot be any doubt that magnetic dust, which in all 

 probability derives its origin from meteors, has often been ob- 

 served, and the question arises, in what way we can increase 

 our knowledge on these points to an apprec'able extent. A 

 further series of occasional observations would in all probability 

 lead to no result of great value, unless they were carried on for 

 a great length of time in suitable places. Meteoric dust, we 

 know, does fall, and observations ought if possible to be directed 

 rather toward, an approximate e-timate of the quantity which 

 falls within a g'ven time. Difficulties very likely will be found 

 in the determination of the locality in which the observations 

 should be conducted. The place ought to be sheltered as much 

 as posdble against any ordinary dust not of meteoric origin. The 

 lonely spots best fitted for these observations are generally 

 accessible to occasional experiments only, and do not lend them- 

 selves easily to a regular series of observations. Nevertheless 

 experiments continued for a few month; at some elevated spot in 

 the Alps might lead to valuable results. The Committee would 

 like to draw attention to an instrument which is well fitted for 

 such observali ms. It was devised by Dr. Pierre Miquel for the 

 purpose of examining, not the meteoric particles, but organic and 

 organised matters floa'ing about in the air. A description, with 

 illu- trations, will be found in the Annuaire de Montsouris for 1 879. 

 Two forms of the instrument are given. In the first form, which 

 is only adapted to permanent places of obseivati'ms, an aspira'or 

 draws a quantity of air through a fine hole. The air impinges 

 on a plate coated with glycerine, which retains all solid matter. 

 By means of this instrument we may determine the quantity of 

 solid particles within a given volume of air. The second, more 

 portable, form does not allow such an accurate quantitative air 

 analysis. The instruitent is attached to a weathercock, and thus 

 is always directed against the wind, which traverses it, and de- 

 posits, as in the other permanent form, its solid matter on a 

 glycerine plate. An anemometer placed in the vicinity serves to 

 give an approximate idea of the quantity of air which has passed 

 through the apparatus. These instruoients have been called 

 aeroscopes by their inventor. It is likely that the second form 

 given to the apparatus will be best fitted for the purpose which 

 the Committee has in view. 



Seventh Report of tlie Committee on Underground Water Sup 

 ply, consisting of Prof. E. Hull, the Rez'. H. W. Crosskey, Capt. 

 Douglas Galton, C.B., Mr. James Glaisher, F.R.S., Prof. G. 

 A. Lebour, Mr. W. Molyneux, Mr. G. H. Morton, Mr. W. 

 Pen^elly, Prof. J. Prestwich, Mr. fames Plant, Mr. James 

 Parker, Mr. T. Roberts, Mr. S. Stooke, Mr. G. J. Symons, 

 Mr. IV. Wldtaker, luas read by Mr. C. E. de Ranee, of H.M.'s 

 Geological Survey, the Secretary. — The Committee was ap- 

 pointed in 1874 at the Belfast Meeting of the Association, with 

 Prof. Hull, LL.D., F.R.S., as Chairman, and Mr. De Ranee, 

 F.G.S., as Secretary and Reporter; its six publisV.ed reports 

 occupy 125 p.age-. of the Society's Proceedings, and the results of the 

 inve.-.tigation;of the Committee show that the Permian, Triassic, 

 and Jurassic formations of Englind and Wales are capable of 

 absorbing from five to ten inches of annual rainfall, giving a 

 daily average yield of from 200,000 to 405,000 gallons per 

 square mile per day. The area occupied by these formations 

 is, in round numbers, Permian and Trias, 8600 square miles, 

 and Oolites, 6600 square miles, capable of yielding 1720 mil 

 lions and 1320 million gallons respectively, at the lowest rate of 

 absorption, or, united, a supply for 100 million people, at thirty 

 gallons a head. Mr. De Ranee then described the « ater-bearing 

 condition of the Yorkshire area, and stated that the investigation 

 V. ould now be extended to all the porous rocks of South Britain. 



Report on the Earthquakes of Japan, by Prof. John Milne. — 

 The author arrives at the following conclusions : — I. That the 

 actual back and forth motion of the ground is seldom more than 

 a few millimetres (usually not equal to imm.), even though 

 chimneys have fallen. 2. The motion usually commences 

 gently, but is very u-reguUr. 3. The number of vibrations per 

 second usually vary betweea three and six. 4. During one 

 shock its direction of motion may be irregular. $• E^-'>f ^'i<i 

 west vibrauons, as recorded in Yedo, have in some cases been 

 shown by lime obervations to have travelled up from the south. 

 6. Many of the shocks which visit Yedo appear to have come 



