Spectra of some of the Fixed Stars. 521 



renders it not presumptuous to attempt to apply the process of 

 reasoning from analogy to those parts of the universe which are 

 more distant from us. 



Upon the earth we find that the innumerable individual re- 

 quirements which are connected with the present state of terres- 

 trial activity, are not met by a plan of operation distinct for each, 

 but are effected in connexion with the special modifications of a 

 general method embracing a wide range of analogous phenomena. 

 If we examine living beings, the persistence of unity of plan ob- 

 servable amidst the multiform varieties of special adaptation of 

 the vertebrate form of life may be cited as an example of the unity 

 of operation referred to. In like manner the remarkably wide 

 range of phenomena which are shown to be reciprocally interde- 

 pendent and correlative of each other, by the recent great exten- 

 sion of our knowledge in reference to the relation of the different 

 varieties of force and their connexion with molecular motion, ex- 

 hibits a similar unity of operation amidst the changes of the 

 bodies which have not life. 



The observations recorded in this paper seem to afford some 

 proof that a similar unity of operation extends through the uni- 

 verse as far as light enables us to have cognizance of material 

 objects. For we may infer that the stars, while differing the one 

 from the other in the kinds of matter of which they consist, are 

 all constructed upon the same plan as our sun, and are composed of 

 matter identical, at least in part, with the materials of our system. 

 The differences which exist between the stars are of the lower 

 order j of differences of particular adaptation, or special modifica- 

 tion, and not differences of the higher order of distinct plans of 

 structure. 



There is therefore a probability that these stars, which are 

 analogous to our sun in structure, fulfil an analogous purpose, 

 and are, like our sun, surrounded by planets, which they by their 

 attraction uphold, and by their radiation illuminate and energize. 

 And if matter identical with that upon the earth exists in the 

 stars, the same matter would also probably be present in the pla- 

 nets genetically connected with them, as is the case in our solar 

 system. 



It is remarkable that the elements most widely diffused 

 through the host of stars are some of those most closely con- 

 nected with the constitution of the living organisms of our globe, 

 including hydrogen, sodium, magnesium, and iron. Of oxygen 

 and nitrogen we could scarcely hope to have any decisive indica- 

 tions, since these bodies have spectra of different orders. These 

 forms of elementary matter, when influenced by heat, light, and 

 chemical force, all of which we have certain knowledge are radi- 

 ated from the stars, afford some of the most important conditions 



