IV 



microscopic science, and will be well prepared to 

 extend his independent researches, without any other 

 limit than that which the finite, though vast, sphere 

 of study itself presents to him. 



The staple of the work now offered to the public 

 "Consists of original observation. The author is far 

 from thinking lightly of the labours of others in this 

 ample field ; but still, it is true, that respecting very 

 many of the subjects that came under his notice, he 

 found, in endeavouring to reproduce and verify pub- 

 lished statements, so much perplexity and difficulty, 

 that he was thrown back upon himself and nature, 

 compelled to observe de novo, and to set down simply 

 what he himself could see. The ever-accumulating 

 stock of observed and recorded facts is the common 

 property of science ; and the author has not scrupled 

 to reproduce, to amplify, or to abridge his own obser- 

 vations which have already appeared in his published 

 works and scientific memoirs, as freely as he would 

 have cited those of any other observer, in which he 

 had confidence, and which were germane to his .pur- 

 pose. Yet, in almost all cases, the observations so 

 used have been subjected to renewed scrutiny, and 

 have been verified afresh, or corrected where found 

 defective. 



In order to relieve as much as possible the dryness 

 of technical description, a colloquial and familiar style 

 has been given to the work ; which has been thrown 

 into the form of a series of imaginary conversaziones, 

 or microscopical soirees, in which the author is sup- 

 posed to act as the provider of scientific entertain- 

 ment and instruction to a circle of friends. It is 

 proper to add, however, that the precision essential 



