Ixxviii REPORT — 1876. 



facts of tlie highest interest. Hydrogen, which, if the ahsolute zero of the 

 physicist does not bar the way, we may hope yet to see in the metallic form, 

 appears to be everywhere present in the universe. It exists in enormous 

 quantity in the solar atmosphere, and it has been discovered in the atmo- 

 spheres of the fixed stars. It is present, and is the only known element of 

 whose presence we are certain, in those vast sheets of ignited gas of which 

 the nebulfe proper are composed. Nitrogen is also widely diffused among 

 the stellar bodies, and carbon has been discovered in more than one of the 

 comets. On the other hand, a prominent line in the spectrum of the Aui'ora 

 Borealis has not been identified with that of any known element ; and the 

 question may be asked : — Does a new element, in a highly rarefied state, 



o 



exist in the upper regions of our atmosphere? or are we with Angstrom to 

 attribute this line to a fluorescent or phosj^horescent light produced by the 

 electrical discharge to which the aurora is due ? This question awaits farther 

 observations before it can be definitely settled, as does also that of the source 

 of the remarkable green line which is everywhere conspicuous in the solar 

 corona. 



I must here pause for a moment to pay a passing tribute to the memory 

 of Angstrom, whose great work on the solar spectrum will always remain as 

 one of the finest monuments of the science of our period. The influence, 



O 



indeed, which the labours of Angstrom and of Kirchhoff have exerted on the 

 most interesting portion of later physics can scarcely be exaggerated; and it 

 may be truly said that there are few men whose loss wUl be longer felt or 

 more deeply deplored than that of the illustrious astronomer of Upsala. 



I cannot pursue this subject further, nor refer to the other terrestrial 

 elements which are present in the solar and stellar atmospheres. Among 

 the many elements that make up the ordinary aerolite, not one has been 

 discovered which does not occur upon this earth. On the whole we arrive at 

 the grand conclusion that this mighty universe is chiefly built up of the same 

 materials as the globe wo inhabit. 



In the application of science to the useful purposes of life, chemistry and 

 mechanics have run an lionourable race. It was in the valley of the Clyde 

 that the chief industry of this country received, within the memory of many 

 here present, an extraordinary impulse from the application by Ncilson of 

 the hot blast to the smelting of iron. The Bessemer steel process and the 

 regcJicrativc furnace of Siemens are later appHcations of high scientific prin- 

 ciples to the same industry. But there is ample work yet to be done. The 

 fuel consumed in the manufactui'e of iron, as, indeed, in every funiace where 

 coal is used, is greatly in excess of what theory indicates ; and the clouds of 

 smoke which darken the atmosphere of our manufacturing towns, and even 

 of whole districts of country, are a clear indication of the waste, but only of 

 a small portion of the waste, arising from imperfect combustion. The de- 

 pressing effect of Ihifl ntinosphero upon Ihc working population can scarcely 



