EXPERIMENT, 179 



mentioned by Liebig, to hasten on decay, and 

 limit the health-destroying influences of putres- 

 cent matters. 



If a globule of water in which they are 

 found is placed on a slip of glass under a 

 microscope, they will, as has been said, 

 be seen swimming about in it with extreme 

 vivacity. Just take the least drop of sulphuric 

 acid on some fine point, of a hair, or a pin, or 

 a feather, and touch the water. They die 

 instantaneously, as if suddenly shot. Nothing 

 can be conceived more momentary than this 

 effect. 



The contemplation of such subjects must 

 ultimately produce great changes in the pro- 

 cess of man's thoughts. How often have 

 we been disgusted in looking upon the red and 

 green colouring matter of some pond or ditch, 

 and regarded it as a nuisance. This view was, 

 like many others in which we indulge, far from 

 the truth. Instead of being what our imagi- 

 nation misrepresented to us, it was a world 

 of beautiful and useful creatures performing 

 unseen the great purposes of Gocf, and actually 

 conferring benefits on us who were regarding 

 them in a wrong light. The remembrance of 

 the errors of ignorance ought to humble us ; 



