PHENOMENA IN THE ANIMAL BODY. 357 



contemplation of the magnitude of the heavenly 

 bodies, and the extent of space through which 

 they range. It will, therefore, be tending to the 

 object of this volume to show that with the mi- 

 croscope, that is, by observing the atoms of our 

 frame which are invisible to the naked eye, we 

 discover motions and actions, both of inorganic 

 and animated particles, which tend to the preser- 

 vation of life, and to the performance of the offices 

 in the animal economy, fully as remarkable as the 

 contractions of the heart, or the play of the lungs. 

 It will be necessary to the correct estimate of 

 the facts which we have to mention, that we ad- 

 vert to a curious discovery of Mr. Brown, relative 

 lo the muiiuijs uf inurgaiiic molecules. 1 nis gen- 

 tleman's celebrity is of a kind which may not 

 readily be comprehended by some readers ; for 

 his retired and philosophical habits cause him to 

 occupy a small space in society at home, in 

 comparison with that reputation which extends 

 wherever science is cultivated. He was directed 

 to this subject by a motion visible in the pollen 

 of plants, when under his microscope, which led 

 him to further investigations ; and he found that 

 when inorganic as well as organic bodies were 

 minutely divided, and floated in a drop of water, 

 active motions were seen in the molecules. The 

 motions of these particles are different from those 

 of animated matter. The molecules are spheri- 

 cal, and between l-20,000th and l-30,000th of an 

 inch in diameter. I have myself seen these, and 



