NATURAL HISTORY OF CREATION. 35 



other's company. One will remain combined in solution 

 with another, till a third is added, when it will abandon 

 the former and attach itself to the latter. A fourth 

 being added, the third will perhnps leave the first and 

 join the new comer. 



Such is an outline of the information which chemistry 

 gives us regarding the constituent materials of our 

 globe. How infinitely is the knowledge increased in 

 interest, when we consider the probability of such being 

 the materials of the whole of the bodies of space, and the 

 laws under which these everywhere combine, subject 

 only to local and accidental variations ! 



In considering the cosmogonic arrangements of our 

 globe, our attention is called in a special degree to the 

 moon. 



In the nebular hypothesis, satellites are considered as 

 masses thrown off from their primaries, exactly as the 

 primaries had previously been from the sun. The orbit 

 of any satellite is also to be regarded as marking the 

 bounds of the mass of the primary at the time when that 

 satellite was thrown off; its speed likewise denotes the 

 rapidity of the rotatory motion of the primary at that 

 particular juncture. For example, the outermost of the 

 four satellites of Jupiter revolves round his body at. the 

 distance of 1,180,582 miles, showing that the planet was 

 once 3,675,501 miles in circumference, instead of being, 

 as now, only 89,170 miles in diameter. This large mass 

 took rather more than sixteen days six hours and a half 

 (the present revolutionary period of the outermost satel- 

 lite) to rotate on its axis. The innermost satellite must 

 have been formed when the planet was reduced to a cir- 

 cumference of 309,075 miles, and rotated in about forty- 

 two hours and a half. 



From similar inferences, we find that the mass of the 



B 2 



