256 ANXUAL OF SCIENTIFIC DISCOVERY. 



in color, the blue and green rays are full of lines, while the few in 

 the red and yellow are far apart ; in its component, on the other hand, 

 which is deep blue, the red and orange part of the spectrum is full of 

 groups of fine lines that interfere with those rays and leave the blue end, 

 which has lines few and far between, as the dominant light of the star. 

 The colors of the components of Ilerculis, which are severally reddish 

 and green, appear to be produced in strict conformity to the same 

 hypothesis ; and although the theory cannot be considered as estab- 

 lished by these instances, it must be regarded as exhibiting a high 

 degree of probability, while the singular variability in the colors of 

 stars at different times, which cannot fail to occur to our readers as 

 not at present explained, may yet prove to be capable of some eluci- 

 dation bv further investigations in the same direction. Of course 



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change in the chemical constitution of the investing atmospheres would 

 be an obvious cause of change of color ; but these latter changes are 

 too frequent and recur with too unvarying a regularity at the known 

 periods, to admit of such an hypothesis. 



The spectrum observations have also an important bearing on the 

 nebular hypothesis of the cosmical origin of the universe, as showing 

 that the elementary substances must have existed in different propor- 

 tions at different points of the nebulous mass, otherwise by condensa- 

 tion equal proportions of the elements, from the surrounding vapor, 

 would have been collected. There is here an analogv to the manner in 



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which the components of the earth's crust are distributed. Some of 

 the elements are widely and universally diffused throughout animal, 

 vegetable, and mineral matter ; while others, as the rarer metals, are 

 accumulated at particular points, and whatever the reason of this 

 separation, the benefits to. the human race caused thereby are many 

 and obvious. 



The knowledge derived from these observations has induced Messrs. 

 Huggins and Miller to indulge in some speculations, which are so 

 legitimate, and so ably put forward by them in their report to the 

 Royal Society, that we can not do better than allow them to speak for 

 themselves, especially as the report itself may not fall within the range 

 of many of our readers. 



" The closely marked connection, in similarity of plan and mode of 

 operation, in those parts of the universe which lie within the range of 

 experiment, and so of our more immediate knowledge, 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 require- 

 ments which are connected with the present state of terrestrial activity, 

 are not met by a plan of operation distinct for each, but are effected 

 in connection with the special modifications of a general method, em- 

 bracing a wide range of analogous phenomena. If we examine living 

 beings, the persistence of unity of plan observable amidst the multi- 

 form 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 interdependent and correlative of each other, by the 

 recent great extension of our knowledge in reference to the relation 

 of the different varieties of forces, and their connection with molecular 



