22 Life and Matter [chap. h. 



until they are discovered, the law of con- 

 servation of energy as now stated may in 

 some cases be strictly untrue ; just as it would 

 be untrue, though partially and usefully true, 

 in the theory of machines, if heat were un- 

 known or ignored. To jump, therefore, 

 from a generalisation such as this, and to say, 

 as Professor Haeckel does on page 5, that 

 the following cosmological theorems have 

 already been " amply demonstrated," is to 

 leap across a considerable chasm : 



" 1. The universe, or the cosmos, is eternal, 

 infinite, and illimitable. 



" 2. Its substance, with its two attributes 

 (matter and energy), fills infinite space, and is in 

 eternal motion. 



" 3. This motion runs on through infinite time 

 as an unbroken development, with a periodic 

 change from life to death, from evolution to 

 devolution. 



"4. The innumerable bodies which are scat- 

 tered about the space-filling ether all obey the 

 same c law of substance ' ; while the rotating 

 masses slowly move towards their destruction and 

 dissolution in one part of space, others are spring- 

 ing into new life and development in other 

 quarters of the universe.' 



