AND OF THE OTHER BODIES OF SI ACE. 19 



versal, or as liable to take place everywhere, as are the 

 laws of gravitation and centrifugal force. We must 

 therefore presume that the gases, the metals, the earths, 

 and other simple substances (besides whatever more of 

 which we have no acquaintance) exist, or are liable to 

 come into existence under proper conditions, as well in 

 the astral system, which is thirty-five thousand times 

 more distant than Sirius, as within the bounds of our own 

 solar system or our own globe. 



Matter, whether it consists of about fifty-five ingredi- 

 ents, or only one, is liable to infinite varities of condition 

 under different circumstances, or to speak more philoso- 

 phically under different laws. As a familiar illustration, 

 water, when subjected to a temperature under 32° Fahren- 

 heit, becomes ice; raise the temperature to 212° and it 

 becomes steam, occupying a vast deal more space than it 

 formerly did. The gasses, when subjected to pressure 

 becc le liquids ; for example, carbonic acid gas, when 

 subjected to a weight- equal to a column of water 1230 

 feet high, at a temperature of 32°, takes this form ; the 

 other gasses require various amounts of pressure for this 

 transformation, but all appear to be liable to it when the 

 pressure proper in each case is administered. Heat is a 

 power greatly concerned in regulating the volume and 

 other conditions of matter. A chemist can reckon with 

 considerable precision what additional amount of heat 

 would be required to evaporize all the water of our globe; 

 how much more to disengage the oxygen which is diffus- 

 ed in nearly a proportion of one- half throughout its so- 

 lids ; and, finally, how much more would be required to 

 cause the whole to become vapcriform, which we may 

 consider as equivalent to its being restored to its original 

 nebulous state. He can calculate with equal certainty 

 what would be the effect of a considerable diminution of 

 the earth's temperature — what changes would take place 

 in each of its component substances, and how much the 

 whole would shrink in bulk. 



The earth and all its various substances have at present 

 a certain volume in consequence of the temperature which 

 actually exists. When, then, we find that its matter and 

 that of the associate planets, was at one time diffused 

 throughout the whole space now circumscribed by the orbit 

 of Uranus, we cannot doubt, after what we know of the 

 power of heat, that the nebulous form of matter was at- 



