416 THE INSTABILITY OF THE HOMOGENEOUS. 



of parts must pass from a uniform into a multiform state. 

 And so on continuously. Whence indeed it is clear that 



not only must the homogeneous lapse into the non-homo- 

 geneous, but that the more homogeneous must tend ever to 

 become less homogeneous. If any given whole, instead of 

 being absolutely uniform throughout, consist of parts dis- 

 tinguishable from each other if each of these parts, while 

 somewhat unlike other parts, is uniform within itself ; then, 

 each of them being in unstable equilibrium, it follows that 

 while the changes set up within it must render it multiform, 

 they must at the same time render the whole more multi- 

 form than before. The general principle, now to be fol- 

 lowed out in its applications, is thus somewhat more compre- 

 hensive than the title of the chapter implies. No demurrer 

 to the conclusions drawn, can be based on the ground that 

 perfect homogeneity nowhere exists; since, whether that 

 state with which we commence be or be not one of perfect 

 homogeneity, the process mast equally be towards a relative 

 heterogeneity. 



150. The stars are distributed with a three-fold irregu- 

 larity. There is first the marked contrast between the 

 plane of the milky way and other parts of the heavens, in 

 respect of the quantities of stars within given visual areas. 

 There are secondary contrasts of like kind in the milky way 

 itself, which has its thick and thin places; as well as 

 throughout the celestial spaces in general, which are much 

 more closely strown in some regions than in others. And 

 there is a third order of contrasts produced by the aggre- 

 gation of stars into small clusters. Besides this heteroge- 

 neity of distribution of the stars in general, considered with- 

 out distinction of kinds, a further such heterogeneity is dis- 

 closed w r hen they are classified by their differences of colour, 

 which doubtless answer to differences of physical constitu- 

 tion. While the yellow stars are found in all parts of the 

 heavens, the red and blue stars arc not so: there are wide 



