146 Proceedings of Philosophical Societies. [Feb. 



and perfect of the sciences, pointed out, as subjects for investi- 

 gation, the nature of the systems of the fixed stars, their changes, 

 Sie relations of cometary bodies to the sun, and the motions 

 of those meteors which throw down showers of stones ; for 

 in a system, he observed, in which all is harmony, even these 

 must be governed by fixed laws, and intended for definite 

 purposes. 



The great question of universal gravitation, audits connexion 

 with the figure of the earth, the President observed, had been 

 long solved. , By the mechanical refinements of a Fellow of the 

 }*iociety, new means had been devised of estimating the force of 

 gravity with exactitude. Sir H. Davy stated the desire which he 

 knew was entertained by the Royal Academy of Sciences at 

 Paris to connect their labours with those carried on by the com- 

 mand of the Board of Ordnance in Britain : should this take 

 place, there would then be established, he observed, on 

 the highest authority, an admeasurement of 1-1 8th of the 

 whole circumference of the earth — a great record for posterity, 

 and an honour to our own times. 



As connected with the subject of the figure of the earth, Sir 

 H. Davy referred to the late voyage to the Arctic regions, which, 

 he observed, presented hopes of greater discoveries ; and he 

 made honourable mention of those by whom the expedition was 

 planned and executed — an expedition which he characterized as 

 worthy of the greatest maritime nation in the world. 



The discoveries of Huygens, Newton, and WoUaston, in the 

 theory of hght and vision, were stated to have been followed by 

 those of Malus. The President then alluded to the subject of the 

 polarization of light, and the labours of other eminent philoso- 

 phers ; and expressed an opinion that this discovery would 

 estabhsh a new connexion between mechanical and chemical 

 philosophy. 



The subject of heat as connected with that of light was 

 remarked as having lately afforded a rich harvest of discovery. 

 The applications of the doctrine of heat to the atomic or corpus- 

 cular philosophy of chemistry were represented by the President 

 as abounding in new views ; and he noticed several facts which 

 fieemed to point to some general law on the subject: 1. The 

 apparent equable motion of radiant matter, or light and heat, 

 through space. 2. The equable expansion of all elastic fluids 

 by equal increments of temperature. 3. The contraction or 

 expansion of gases by chemical changes, in some direct ratio to 

 their original volume. 4. The circumstance that the elementary 

 particles of all bodies appear to possess the same quantity of 

 neat. 



The wonderful electrical instrument of Volta had done more, 

 it was remarked, for the obscure parts of physics and chemistry, 

 than the microscope for natural history, or even the telescope 



