232 AITNUAL OF SCIEKTIFIC DISCOVICRT. 



(either potassium, sulphur, or phosphorus) lends its aid, but in a 

 much less remarkable degree, to produce the same luminous 

 trains." — Reader. 



EESULTS OF SPECTRUM ANALYSIS ArPLIED TO THE 

 HEAVENLY BODIES. 



The followinjr are extracts from a lecture delivered before the 

 Britisli Association, at Nottingham, Aug. 23, 18GG, by William 

 Huggins, F.R.8. : — 



"1 Ijring hcl'ore you some additions to our knowledge in the 

 department of astronomy, which l)ave followed from a compara- 

 tively recent discovery. The I'csearclies of Kircliholf have jjlaccd 

 in the hands of the astronomer a method of analysis which is spe- 

 cialh' suitable for the examination of the heavenly bodies. So un- 

 expecteil and important are the results of the application of spec- 

 trutn anrdysis to the olijects in the heavens, that this method of 

 observation may be said to have created a new and distinct branch 

 of astronomical science. 



" I'liysical astronomy, the imperishable and ever-growing mon- 

 ument to the memory of Newton, may be descrii)ed as the exten- 

 sion of terrestrial dynamics to the heavens. It seeks to explain 

 the movements of the celestial bodies on the supposition of the 

 universality of an attractive force, similar to that which exists upon 

 the earth. 



" The new branch of astronomical science, which spectrum 

 analysis may be said to have founded, has for its olijcct to extend 

 the laws of terrestrial physics to the other phenomena of the heav- 

 enly bodii'S ; and it rests upon the now established fact, that matter 

 of a natiu'c common to that of the earth, and sul)ject to laws simi- 

 lar to those which prevail upon the earth, exists throughout the 

 stellar nnivei-se. 



" The peculiar importance of KirchhofTs discovery to astronomy 

 becomes obvious, if we consider the position in which we stand to 

 the heavenly bodies. Gravitation and the laws of our being do 

 not permit us to leave the earth ; it is therefore by means of light 

 alone that we can obtain any knowledge of the grand array of 

 worlds which surround us in cosmical space. The star-lit heavens 

 is the only chart of the universe we have, and in it each twink- 

 ling point is the sign of an immensely vast, though distant, region 

 of activity. 



"Hitherto the light from the heavenly bodies, even when col- 

 lected by the largest telescopes, has conveyed to us but very mea- 

 gre information, and in some cases only of their form, their size, 

 and their color. The discovery of Kirchhoff enables us to inter- 

 pret symbols and indications hidden within the light itself, which 

 furnish trustworthy information of the chemical, and also to some 

 extent of the physical, condition of the excessively remote bodies 

 from which the light has emanated. 



" We are indebted to Newton for the knowledge that the beau- 

 tiful tints of the rainbow are the common and necessary ingredi- 

 ents of ordinary light. He found that when white light is made 



