134 FROM NEBULA TO NEBULA 



regularity reaches its volatile point at a much greater 

 depth than the average, and so results in cataclysmic 

 eruptions. What the constitution of this knot may be 

 I cannot undertake to say, but I would suggest care- 

 ful spectroscopic analysis of sun-spot spectra as the like- 

 ly means of ascertaining the fact- There may, of course, 

 be more knots than one, and of different substances, 

 so that any variety or degree of irregular variability 

 may readily be accounted for. The precisely regular 

 variables, I should say, are due to eclipses, as indeed 

 astronomers generally agree. 



New stars, such as Nova Persei, are variables in 

 their final act of transformation. They flare up sud- 

 denly from a very low to a very high magnitude, and 

 then gradually fade away, never to reappear. -They 

 are neither more nor less than exploding suns, suicides 

 by their self-generated passions, passing back again 

 into their nebulous ghosts: thus closing the enthralling 

 drama of Nature, and supplying the final link in th- 

 cycle of celestial change. 



If the Newtonian first law of inertia be even ap- 

 proximately true, which I am persuaded it is, we have 

 here the explanation of the marvelous celerity exhibited 

 in the spread of the nebula from Nova Persei, for an 

 exploding sun may not unreasonably be conceived to 

 drive its particles through vacuous space with a veloc- 

 ity comparable to and perhaps exceeding that of light. 

 The nebulse thus formed being but random clouds, their 

 degrees of nebulosity and capriciousness of form lose 

 much of their significance, nnd consequently much of 

 their interest, to the scientist. The nuclei seen in spiral 

 nebulae are either the larger fragments of the original 

 sun, or else the planets that circled it in the past, grow- 

 ing fat from feeding upon its disintegrated carcass. 



