Sept. 2, 1880] 



NATURE 



David's, &c., were attended by a fair number of visitors, 

 but the exertions of the Excursion Committees had made 

 more than ample accommodation for the limited number 

 of excursionists. The excursions announced for to-day 

 were numerous, and of an interesting character ; but 

 several of them have been withdrawn, in consequence of 

 the smallness of the number of applications. 



The first of the two evening soirees was a reception by 

 the Mayor of Swansea, and was enlivened by some 

 excellent music by a local chorus and orchestra. There 

 were a number of exhibits of machinery in motion, and of 

 products of local industries. 



The second of the soirees was held on the evening of 

 Tuesday, the 31st, and was more particularly devoted to 

 scientific apparatus. The temporary pavilion in Burrows 

 Square, in which these entertainments were given, was 

 illuminated by the light of the Jamin candle lately de- 

 scribed in Nature, giving an agreeable and briUiant 

 light, though somewhat unsteady, under the disadvanta- 

 geous conditions under which it had to be set up and 

 worked. 



The evening lectures cannot be said to have been 

 largely patronised, although perhaps the geographical 

 difficulties of the tov/n may have accounted to some 

 extent for this state of things. Prof. Boyd Dawkins's 

 discourse on " Primaeval Man," excellently dehvered and 

 admirably illustrated, was very attentively listened to and 

 enthusiastically applauded. Mr. F. Gallon's lecture on 

 " Mental Imagery" was illustrated by diagrams of some 

 of the singular generic photographs with which he has 

 identified his name ; great amusement being evoked by 

 the exhibition of the face of a "generalised" Welsh 

 Dissenting minister, compounded from photographs of 

 sundry Nonconformist divines of Swansea. Mr. F. 

 Seebohm lectured on the North-east Passage to a 

 small but very attentive audience of working men on 

 Saturday evening, dwelling more particularly on the 

 heroic exploits of Nordenskjold and of Capt. Willing. 



At the meeting of the General Committee on Monday 

 arrangements were made for the holding next year at 

 York of the jubilee gathering of the Association. The 

 proceedings were unusually interesting and enthusiastic. 



Sir John Lubbock was chosen as President, the Vice- 

 Presidents being His Grace the Archbishop of York, 

 and those Past-Presidents of the Association who were 

 living when it was founded in 1S31. As Presidents of the 

 Sections the following have been chosen, all of whom are 

 Past-Presidents of the Association : — Mathematics and 

 Physics, Sir William Thomson ; Chemistry, Prof. William- 

 son ; Geology, Prof. Ramsay ; Biology, Prof Owen ; Geo- 

 graphy, Sir J. Hooker; Mechanics, Sir Wm. Armstrong. 



After a stout competition between Southampton, Not- 

 tingham, and Southport, the firit-mentioned of these 

 places was selected for the meeting of 18S2. 



At the final meeting of the Association on Wednesday, 

 the following grants were made : — 



A — Mal/iematics and Physics £ 



Prof. G. C. Foster — Electrical Standards 100 



Mr. G. H. Danvin — Lur.ar Disturbance of Gravity 30 



Prof. Fverett — Underground Temperatures 20 



Dr. Joule — Mechanical Equivalent of Heat 40 



Dr. O. J. Lodge — High Insulation Key J 



Sir Wm. Thomson — Seismic Experiments 30 



Sir \Vm. Thomson. — Tidal Observation 10 



Mr. J. M. Thomson. — Inductive Capacity of Crystals and 



Parailin 10 



B — Chemical Science 



Dr. Gladstone.^Specific Refractions 10 



Lord Rayleigh. — Spectrum Analysis 10 



C — Geology. 



Prof. Duncan — Fossil Polyzoa 10 



Mr. J. Evans — Geological Record 100 



411 



. 25 



Prof. E. Hull — Underground Waters 



Prof. A. C. Ramsay — Earthquake in Japan ... . 



Dr. Sorby — Metamorphic Rocks 10 



D— Biology 



Dr. M. Foster — Scottish Zoological Station 50 



Dr. M. Foster— Naples Zoological Station 75 



Mr. Godwin Austen — Natural History of Socotra 50 



Prof. Gwyn Jeffreys — Exploration of Sea Bed North of 



Hebrides 5° 



General Pitt Rivers — Anthropological Notes 20 



Dr. Pye Smith. — Elimination of Nitrogen diu-ing Bodily 



Exercise 50 



Mr. P. L. Sclater.— Natur.al History of Timor Laut ... 50 



INIr. Stainton. — Zoological Record Joo 



F — Statistics and Economic Science 



Mr. F. Galton. — Estimation of Weights and Heights 

 of Human Beings 



30 



G — Mcclianical Science 



Mr. Bramwell. — Patent Laws 



Mr. J. Glaisher. — Wind Pressure 



Prof. O. Reynolds. — Steering Steamships ... 



SECTION A 



TiIATHEMATICS AND PHYSICS 



Opening Address by Prof. W. Grylls Ad.^ms, M.A., 

 F.R.S., President of the Section 



It has been said by a former President of this Section of the 

 British Association that the president of a Section ought to 

 occupy your time, not by speaking of himself or his own feel- 

 ings, but by a review " more or less extensive of those branches 

 of science which form the proper business of his section." _ He 

 may give a rapid sketch of the progress of mathematical science 

 during the year, or he may select some one special subject, or he 

 may take a middle course, neither so extensive as the first nor so 

 limited as the second. 



There are many branches of science which have always been 

 regarded as properly belonging to our section, and the range is 

 already wide ; but it is becoming more and more true every day 

 that the sciences which are dealt with in otlier sections of the 

 Association are becoming branches of Physics, i.e., are yielding 

 results of vast importance when the methods and established 

 principles of Physics are applied to them. I wish to direct your 

 attention to investigations which are being made in that fertile 

 region for discovery, the "border land" between Chemistry and 

 Physics, where we have to deal witli the constitution of bodies, 

 and ^^here we are tempted to speculate on the existence of 

 matter and on the nature of the forces by which the different 

 parts of it are bound together, or become so transformed that all 

 re:emblance to their former state is lost. It ii not long smce 

 the theory of exchanges became thoroughly recognised in the. 

 domain of Radiant Heat, and yet it is already recognised and 

 accepted in the theory of Chemical Combination. Just as the . 

 molecules of a body which remains at a constant temperature 

 are continuously giving up their heat motion to surrounding 

 molecules, and getting back from them as much motion of the 

 same kind in return, so in a chemical compound which does not. 

 appear to be undergoing change, the combining molecules are 

 continuously giving up their chemical or combining motions to 

 sun-ounding molecules, and receiving again from them as much 

 combininglnotion in return. We may say that each rnolecule 

 is, as far as we can see, constantly dancing in perfect time with 

 a partner, and yet is continuously changing p.irtners. When 

 such an idea of chemical motion is accepted, we can the more 

 easily understand that chemical combination means the alteration 

 of chemical motion which arises from the introduction of a new 

 element into the space already occupied, and the consequent 

 change in the motion of the new compound as revealed to us 

 in tlie spectroscope. We can also the more readily understand 

 that in changing from the old to the new forni or rate of motion 

 there may be a development of energy in the shape of heat-motion 

 which may escape or become dissipated wherever a means of 

 escape presents itself. We know from the experiments of M. 

 Favre that as much heat is absorbed during the decomposition 



