250 INORGANIC CHEMISTRY 



magnesium, and aluminium. Sir Norman Lockyer, in his beautiful 

 spectral studies on the analysis of the heavenly bodies, showed that 

 the sun contained also cadmium, strontium, cerium, lead, and potas- 

 sium. Higgins followed this up by examining the spectra of stars 

 and nebulae, in which he met with the same elements. Le P. Secchi 

 showed that the spectrum of comets gave the rays of the hydro- 

 carbons. 



This whole great question was reviewed and put into shape by use of 

 new methods, by Rowland, professor in the university at Baltimore. 

 He has given us the most important results that we possess on the 

 composition of the sun as determined by the study of its spectrum. 

 He has distinguished 20,000 rays, only a third of which are surely 

 coincident with our terrestrial rays. It is true, however, that among 

 the coincidences occur the most powerful rays of elementary bodies. 

 Rowland concludes from this that if the earth were raised to the tem- 

 perature of the sun, it would give almost the same spectrum. 



Inorganic chemistry has further utilized spectral analysis for the 

 study of band spectra, which serve the chemist as a means of ana- 

 lysis. 



Were there any need of another example to show the fusion of inor- 

 ganic chemistry and physics, we could recall the many applications 

 of electrolysis which are utilized by chemists. Scarcely had Volta 

 published his great discovery of the electric pile when Carlisle and 

 Nicholson put it into use for the decomposition of water, and only 

 a few years afterwards Humphry Davy prepared by this process the 

 metals of the alkalies and alkaline earths. These metals in their turn 

 served for the isolation of boron, silicon, magnesium, and aluminium. 



Since that time, not a year passes without calling in electrolysis to 

 enlarge the field of our discoveries. Many metalloids and metals are 

 obtained to-day by this means, and the most active agent in inorganic 

 chemistry, fluorin, could be isolated by no other method. But we 

 ought also to recall that the study of electrochemistry, and the splen- 

 did researches of Faraday on electric conductivity, completed and 

 extended as they were by Kohlrausch, have started chemistry in a 

 new direction which has led to most valuable results. So true is this 

 that Lord Rayleigh could say, at the Montreal meeting of the British 

 Association, "It is by the study of electrolysis that we can hope to 

 increase our knowledge of chemical reactions and of the forces that 

 produce them; in my opinion, the next advance of the science will be 

 by that road." 



This penetration of physics into chemistry became more complete 

 as the result of the masterly studies of Henri Sainte Claire Deville 

 on dissociation. By systematically examining the incomplete decom- 

 positions of a certain number of substances and by showing the close 

 connection between this dissociation and evaporation, Deville broke 



