358 Dr. T. Sterry HunVs Lecture — 



matter whicli appears in the flames of burning gas and in most other 

 terrestrial flames, or compared even with the light which has 

 emanated from the sun itself. 



But still further, the spectroscope has enabled us to discern in the 

 matter of the sun, and, to a certain extent, in the matter of the fixed 

 stars — which, as you are well aware, are other suns, the centres of 

 other systems — for the most part the same elements with those which 

 make up our own earth. 



You have probably already had explained to you in this place — 

 and it would be foreign to my object to-night to speak of it — the 

 mode in which these investigations have been conducted ; but of the 

 great conclusion you are aware, that the commonest elements, the 

 sodium, the iron, the magnesium, and most of the other commonest 

 elements of the crust of the earth also enter into the composition of 

 the sun, and enter into the composition, moreover, of the fixed 

 stars — that is to say, of other suns. And here it is singular how 

 modem science has realized the gentle intuition of the poet. Long 

 since we heard a poet singing, who told us that he 

 " Saw alike in stars and flowers a part 

 Of the self-same universal being 

 That is throbbing in his mind and heart ; " 



and this, which seemed little more than a poet's fancy, has been 

 realized in the most prosaic way by modern investigation, which 

 shows us from the examination of the light of the sun and of the 

 stars, the very elements which enter into the composition of our own 

 earth — which actually enter into the composition of our own bodies. 

 Still farther, we know the sun is intensely heated. Calciilations 

 have been made as to the amount of heat and of light which have 

 radiated from the sun, and of the temperature of the surface of the 

 sun. The figures which are required to represent that heat are so 

 immense that it is really difficult for the mind to conceive of the 

 intense elevation of temperature which exists in that body. And 

 modern chemical investigation has thrown a curious light, it seems 

 to me, upon the natm-e of the action which is going on at the sun's 

 surface, and upon the source of the luminosity of that body. We all 

 know that heat is favourable to chemical combination, — that, under 

 ordinary conditions in the laboratory, if we wish to effect a com- 

 bination of two bodies, we expose them to heat; but it has been 

 found that a higher degree of heat reverses all these affinities, or 

 most of them. Many of the metals — ^the " noble metals," as we 

 call them, like gold and silver — are capable of forming combinations 

 with oxygen, for instance, but at a higher temperature the oxygen 

 goes off and the metal is regenerated. A similar thing was shown 

 many years ago by Mr. Grove, with regard to water. The elements 

 of water, oxygen and hydrogen, brought together at the elevated 

 temperature of the electric spark, unite to form water ; but at a still 

 higher temperature the compound is again broken up into its two 

 elements, so that if you have these elements at a very high tem- 

 perature, cold would actually produce the effect of combination. A 

 certain point, either of heat or cold, would really produce a similar 



