X PREFACE. 



cature of a microscope has been purchased and used under guch circum- 

 stances. 



We indulge a faint hope that the information conveyed in the following 

 pages will enable the inexperienced reader to avoid these mistakes, and to 

 assign a proper value to the certificates of clergymen and editors who 

 vouch for the excellence of articles concerning whose properties and uses 

 they are profoundly ignorant. These two classes we single out for repro- 

 bation, because in this respect, at least they seem to be sinners above 

 all other men. 



As stated in the title page, it is intended for beginners, and not for 

 beginners in the use of the microscope only, b*ut for those who have had 

 little or no experience in the use of instruments of any kind. Hence the 

 directions that are given are of the very simplest kind, arid all theoretical 

 explanations have been avoided, for the reason that any person that is 

 desirous of studying the optical principles upon which the microscope is 

 constructed will find in the ordinary text books on natural philosophy all 

 the information he may want. Our object has been solely to impart such 

 information as will enable the reader to make a beginning in the. practice 

 of microscopy, hoping that the start thus given will lead him to proceed 

 with his studies, and ultimately acquire that knowledge, skill and dexter- 

 ity which will enable him to avail himself of the extraordinary powers and 

 advantages which the use of this instrument confers, both in scientific 

 pursuits and in everyday life. Above all things, therefore, we have en- 

 deavored to be accurate in our statements and judicious in our directions, 

 and the reader is assured that no processes or methods are given which 

 we ourselves have not frequently and successfully put in practice. 



JOHN PHIN. 

 New Yor1c t January, 1875. 



