PREFACE 5 



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 supposed to 

 act as the provider of scientific entertainment and instruc- 

 tion to a circle of friends. It is proper to add, however, 

 that the precision essential to science has never been con- 

 sciously sacrificed. A master may be easy and familiar 

 without being loose or vague. 



A considerable amount of information will be found 

 incidentally scattered throughout the work, on micro- 

 scopic manipulation the selecting, securing, and prepar- 

 ing objects for examination; an important matter, and 

 one which presents a good deal of practical difficulty to 

 the beginner. Not a little help will be afforded to him, 

 also, on the power to observe and to discriminate what 

 he has under his eye. In almost every instance, the ob- 

 jects selected for illustration are common things, such as 

 any one placed in tolerably favorable circumstances, with 



