BOOK I. 



Of the multiplicity of objects, which the almost in- 

 credible powers of the Microscope have brought under 

 our observation and scrutiny, perhaps that class of ani- 

 mated beings denominated Animalcules may be con- 

 sidered the most remarkable. The bare knowledge that 

 there are myriads of atoms (and in the scale of living 

 creatures we can call them nothing else) existing in a 

 single drop of water, recreating and executing all their 

 various functions and evolutions with as much rapidity 

 and apparent facility as if the range afforded them were 

 as boundless as the ocean, must carry with it an inten- 

 sity of interest to the mind of every human being ; of 

 every one, at least, who is at all accustomed to meditate 

 on the perfections of Nature, and to recognize and adore 

 the hand that guides her through all the vast variety of 

 her stupendous operations. As our acquaintance with 

 the minute portions of the creation is exclusively de- 

 pendent upon the properties of the Microscope, every re- 

 finement of this interesting and valuable instrument must 

 necessarily contribute something to our stock of know- 

 ledge on the subject ; and indeed it is entirely owing to 

 the very great perfection which it has now acquired, that 

 a fresh spirit of research is widely extending itself, — a 



