64 LAY SERMONS, ESSAYS, AND REVIEWS. [v. 



disturbance will subside equilibrium will be restored, and the 

 water will return to its passive state. 



Expose the water to cold it will solidify and in so doing its 

 particles will arrange themselves in definite crystalline shapes. 

 But once formed, these crystals change no further. 



Again, substitute for the lump of gold some substance capable 

 of entering into chemical relations with the water : say, a mass 

 of that substance which is called &quot; protein &quot; the substance of 

 flesh : a very considerable disturbance of equilibrium will take 

 place all sorts of chemical compositions and decompositions will 

 occur ; but in the end, as before, the result will be the resump 

 tion of a condition of rest. 



Instead of such a mass of dead protein, however, take a particle 

 of living protein one of those minute microscopic living things 

 which throng our pools, and are known as Infusoria such a 

 creature, for instance, as an Euglena, and place it in our vessel of 

 water. It is a round mass provided with a long filament, and 

 except in this peculiarity of shape, presents no appreciable 

 physical or chemical difference whereby it might be distinguished 

 from the particle of dead protein. 



But the difference in the phenomena to which it will give rise 

 is immense : in the first place it will develop a vast quantity of 

 physical force cleaving the water in all directions with consider 

 able rapidity by means of the vibrations of the long filament or 

 cilium. 



Nor is the amount of chemical energy which the little creature 

 possesses less striking. It is a perfect laboratory in itself, and it 

 will act and react upon the water and the matters contained 

 therein; converting them into new compounds resembling its 

 own substance, and at the same time giving up portions of its 

 own substance which have become effete. 



Furthermore, the Euglena will increase in size ; but this 

 increase is by no means unlimited, as the increase of a crystal 

 might be. After it has grown to a certain extent it divides, and 

 each portion assumes the form of the original, and proceeds to 

 repeat the process of growth and division. 



