NEBULAE. 189 



probably related to each other in the order ,of time, and we are irresistibly led to the 

 conclusion, that the vegetable world in the one case, and the sidereal world in the other, 

 exhibit at one instant a succession of changes requiring time, which the life of man or 

 the duration of a solar system may not be sufficient to trace out in individual instances." 

 The difference is immense between the oak that for centuries has braved the breeze, and 

 the sapling that has not yet borne an acorn, and parallel to it is that between a rude 

 nebulosity and a stellar orb. Yet, if we deny an identity in the latter case, because we 

 cannot produce an instance of actual progression from the one to the other, so might the 

 insect of an hour, if endowed with intelligence, reason against an identity in the former 

 instance, because ten thousand generations of its race are born, live, and perish during 

 the period which sensible development requires. It has been conceived, therefore, that 

 the nebula? furnish the true theory of physical existence a key to the origin of the 

 worlds and the systems of worlds which are disclosed around us an unveiling, too, of 

 the early history and first estate of the solar universe a diffused nebulosity gradually 

 advanced by the mutual attraction of its particles into dense spheroids, formed by the 

 action of centripetal and centrifugal forces. 



The theory may be premature, or hereafter proved positively erroneous, but in the present 

 state of general physics, it is entitled to attention because sustained by some striking evi- 

 dence, having certainly far more in its favour than could be advanced for the system of Co- 

 pernicus in the early stages of its history. Those who have treated the nebular hypothesis 

 with ridicule have strangely forgotten what is daily passing before their eyes forgotten 

 the uniform plan of Providence with reference to the world in which we live. What is 

 man full-grown, active, intellectual man as he appears in the maturity of his powers, 

 the noontide of his day, but an example of ascension from a crude to a higher condition ? 

 By gradual and slow degrees, he acquires his vigour of frame, fluency of speech, agility 

 of movement, and furniture of mind. There was a time when the profound moralist or 

 philosopher, who has become the guide of his fellows, was unable to guide himself ; when 

 he who is the sustainer of others was himself the sustained ; when he who can now fear- 

 lessly go forth to traverse earth and ocean could not move a yard from his mother's knee by 

 his own independent energy. Practising an unerring geometry, he can measure the space 

 between the poles, the centre, and the circumference of his terrestrial habitation. He 

 can calculate the extent of the planetary universe, predict the return of the far-wandering 

 comet, and measure the interval between him and the stars ; but upon a period in his 

 history he can look back when the compass of a mile was a formidable adventure, and the 

 crossing of a pathway an impossible achievement. The founder of physical astronomy, 

 who discovered the wonderful law of matter gravitating to matter with a force directly 

 proportioned to the mass of the attracting body, and inversely to the square of its distance 

 from the body which it attracts he who seized upon the sunbeam and disclosed the 

 constituent rays of light, detecting the origin of its various hues, and building up the 

 details of optical science he who thus stood forth confessedly eminent over eminence in 

 the world of intellect was once a stranger to the lowest elements of knowledge, as 

 unable to express his wants as to anticipate his destiny. There is thus in the physical 

 and mental constitution of every individual an illustration of the law of Progress. We 

 start not into life in full maturity of mind and body, but grow up to be what we are by 

 slow and imperceptible degrees. From the moment when existence commences, the years 

 that roll over our heads carry us onward in the march of their changing administration, 

 from a helpless and imperfect condition of being, through stages of awakening thought, 

 expanding intellect, and improving physical capacity, until the full stature of man 

 is gained, rife with life and replete with energy : and what is the period of human evolu- 

 tion, the time of childhood and youth, when compared with the brief term of terrestrial 



