THE PLANETS, ARE THEY INHABITED ? 



disturbances to which it is exposed such as the action of winds 

 and other natural effects. But what, let us ask, regulates this 

 necessary quantity of strength ? What is the chief resistance 

 which it has to overcome ? We answer, mainly the weight of 

 the creature itself. But again ; what is this weight? It is a 

 force produced by what 1 By the combined attractions of the 

 whole mass of matter composing the globe of the earth, exercised 

 upon the matter composing the creature itself ; thus the weight 

 of a man is merely the amount of the attraction of the globe 

 of the earth exercised upon the matter composing the body of 

 the man. The amount of this attraction, therefore, depends 

 upon the quantity of matter in the earth ; but not on that alone ; 

 it is a universal law of nature, that the energy of the attraction 

 exerted by matter, is increased with the proximity of the attracted 

 body to the centre of the attracted mass. Now, if the matter 

 composing the globe of the earth were condensed into half its 

 present bulk, all bodies placed upon the surface, being propor- 

 tionally nearer the centre, would be attracted with greater 

 energy ; and, on the other hand, if the matter of the earth were 

 swelled into a larger bulk, the distance of objects on the surface 

 from the centre being proportionally increased, the energy of the 

 attraction would be diminished. In the one case the weights of 

 all bodies would be augmented, and in the other they would be 

 diminished. The weights, then, of bodies placed on the surface 

 of the earth depend conjointly on the mass of matter composing 

 the earth, and on its density. 



11. It is evident then, that the adaptation which we see usually 

 to prevail between the strength of animals and plants and their 

 weights, is, in reality, an exquisite harmony which is maintained 

 between the strength of these infinitely various tribes of organised 

 creatures, and the mass and density of the globe upon which 

 they are placed ; the slightest disturbance or change in this 

 relation would utterly derange the fitness of things, and would 

 render the globe and its occupants, whether animal or vegetable, 

 unsuited to each other. The amount of attraction, or, to use the 

 more familiar term, the weight of the body on the surface of the 

 globe is, then, an index, so to speak, to the organisation of the 

 creatures placed upon the globe. If we would, then, inquire 

 respecting the probable organisation of the dwellers upon the 

 planets, one of the means of our inquiry would be to ascertain 

 what would be the weights of bodies upon their surfaces. Physical 

 science enables us perfectly to accomplish this The jnasses of 

 matter composing all the planets have been d'scovered with a 

 great degree of precision. Their magnitude have also been 

 measured. Now, to ascertain the weights of budies placed upon 

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