226 THE CANADIAN NATURALIST. [May 



luminous when compared with the sun. It would be out of place, 

 on the present occasion, to discuss the detailed results of spectro- 

 scopic investigation, or the beautiful and ingenious methods by 

 which modern science has shown the existence in the sun, and in 

 many other luminous bodies in space, of the same chemical 

 elements that are met with in our earth, and even in our own 

 bodies. 



Calculations based on the amount of light and heat radiated 

 from the sun show that the temperature which reigns at its surface 

 is so great that we can hardly form an adequate idea of it. Of 

 the chemical relations of such intensely heated matter, modern 

 chemistry has made known to us some curious facts, which help 

 to throw light on the constitution and luminosity of the sun. 

 Heat, under ordinary conditions, is favourable to chemical com- 

 bination, but a higher temperature reverses all affinities. Thus, 

 the so-called noble metals, gold, silver, mercury, etc., unite with 

 oxygen and other elements ; but these compounds are decomposed 

 by heat, and the pure metals are regenerated. A similar reaction 

 was many years since shown by Mr. Grove with regard to water, 

 whose elements — oxygen and hydrogen — when mingled and kindled 

 by flame, or by the electric spark, unite to form water, which, how- 

 ever, at a much higher temperature, is again resolved into its 

 component gases. Hence, if we had these two gases existing in 

 admixture at a very high temperature, cold would actually effect 

 their combination precisely as heat would do if the mixed gases 

 were at the ordinary temperature, and literally it would be found 

 that " frost performs the effect of fire." The recent researches 

 of Henry Ste.-Claire Deville and others go far to show that this 

 breaking up of compounds, or dissociation of elements by intense 

 heat, is a principle of universal application ; so that we may 

 suppose that all the elements which make up the sun or our planet, 

 would, when so intensely heated as to be in that gaseous condition 

 which all matter is capable of assuming, remain uncombined — 

 'that is to say, would exist together in the condition of what we 

 call chemical elements, whose further dissociation in stellar or 

 nebulous masses may even give us evidence of matter still more 

 elemental than that revealed by the experiments of the laboratory, 

 where we can only conjecture the compound nature of many of the 

 so-called elementary substances. 



The sun, then, is to be conceived as an immense mass of 

 intensely heated, gaseous and dissociated matter, so condensed, 



