14 REPORT 1895. 



ciently high to break up our chemical elements into finer forms. Other 

 students of these phenomena may not agree in this view, and pos- 

 sibly the discrepancies may be due to default in our terrestrial 

 chemistry. Still, I would recall to you that Dr. Carpenter, in his Presi- 

 dential Address at Brighton in 1872, almost censured the speculations of 

 Frankland and Lockyer in 1868 for attributing a certain bright line in 

 the spectrum of solar prominences (which was not identifiable with that 

 of any known terrestrial source of light) to a hypothetical new substance 

 which they proposed to call ' helium,' because ' it had not received that 

 verification which, in the case of Crookes' search for thallium, was afforded 

 by the actual discovery of the new metal.' Ramsay has now shown that 

 this gas is present in dense minerals on earth ; but we have now also 

 learned from Lockyer that it and other associated gases are not only 

 found with hydrogen in the solar chromosphere, but that these gases, 

 with hydrogen, form a large percentage of the atmospheric constituents of 

 some of the hottest stars in the heavens. 



The spectroscope has also made us acquainted with the motions and 

 even the velocities of those distant orbs which make up the sidereal uni- 

 verse. It has enabled us to determine that many stars, single to the eye, 

 are really double, and many of the conditions of these strange systems 

 have been revealed. The rate at which matter is moving in solar cyclones 

 and winds is now familiar to us. And I may also add that quite recently 

 this wonderful instrument has enabled Professor Keeler to verify Clerk- 

 Maxwell's theory that the rings of Saturn consist of a marvellous com- 

 pany of separate moons — as it were, a cohort of courtiers revolving round 

 their queen — with velocities proportioned to their distances from the 

 planet. 



Physics 



If we turn to the sciences which are included under physics, the pro- 

 gress has been equally marked. 



In optical science, in 1831 the theory of emission as contrasted with 

 the undulatory theory of light was still under discussion. 



Young, who was the first to explain the phenomena due to the inter- 

 ference of the rays of light as a consequence of the theory of waves, and 

 Fresnel, who showed the intensity of light for any relative position of the 

 interference-waves, both had only recently passed away. 



The investigations into the laws which regulate the conduction and 

 radiation of heat, together with the doctrine of latent and of specific heat, 

 and the relations of vapour to air, had all tended to the conception of a 

 material heat, or caloric, communicated by an actual flow and emission. 



It was not till 1834 that improved thermometrical appliances had 

 enabled Forbes and Melloni to establish the polarisation of heat, and thus 

 to lay the foundation of an undulatory theory for heat similar to that 

 which was in progress of acceptation for light. 



Whewell's report, in 1832, on magnetism and electricity shows that 



