90 THOUGHTS ON ANIMALCULES. 



We may, indeed, take cognisance of some of the ob- 

 vious results of the operations of these living atoms ; 

 such, for example, as their influence in maintaining the 

 purity of the atmosphere and of the water, by the 

 conversion into their own structures of the particles 

 liberated by the decomposition of the larger animals 

 and vegetables ; and, in their turn, becoming the food of 

 other races, and thus affording the means of support to 

 creatures of a hio-her oro^knisation than themselves. 

 We see, too, that many species, after death, give rise 

 to the formation of earthy deposits at the bottoms of 

 lakes, rivers, and seas, which, in after-ages, may be- 

 come fertile tracts of country, and the sites of large 

 communities of mankind. But in this, as in all at- 

 tempts to interpret the mysterious designs of Pro- 

 vidence, we are but as " beings darkly wise ; " for it is 

 probable that many of the most serious maladies which 

 afflict humanity, are produced by peculiar states of in- 

 visible animalcular life. From some periodical and ex- 

 aggerated condition of development, particular species, 

 too minute for the most powerful microscope to descry, 

 may suddenly swarm in the air or in the waters, 

 and penetrating the internal vessels and organs, exert 

 an injurious influence of a specific character on the 

 lining membranes, and fluids, of the human frame. 

 And from this inscrutable agency may, possibly, ori- 



