20 THE MICROSCOPIST. 



of the effects of various physical and chemical agencies, a 

 steady hand, and a quick-discerning eye. Above all, 

 microscopy requires a cultured mind, capable of readily 

 detecting sources of fallacy, and such a love of truth as 

 enables a man to free himself from all preconceived no- 

 tions of structure and from all bias in favor of particular 

 theories and analogies. What result is it possible to draw 

 from the observations of those who boil, roast, macerate, 

 putrefy, triturate, and otherwise injure delicate tissues, 

 except for the purpose of isolating special structures or 

 learning the effects of such agencies ? Yet many of the 

 phenomena resulting from such measures have been de- 

 scribed as primary, and theories of development have been 

 proposed on the basis of such imperfect knowledge. 



Borelli (1608-1656) is considered to be the first who 

 applied the microscope to the examination of animal 

 structure. Malpighi (1661) first witnessed the actual cir- 

 culation of the blood, which demonstrated the truth of 

 Harvey's reasoning. He also made many accurate obser- 

 vations in minute anatomy. Lewenhoeck, Swammerdam, 

 Lyonet, Lieberkuhn, Hewson, and others, labored also in 

 this department. When we remember that these early 

 laborers u;ed only simple microscopes, generally of their 

 own construction, we must admire their patient industry, 

 skilful manipulation, and accurate judgment. In these 

 respects they are models to all microscopists. 



Within the last quarter of a century microscopic ob- 

 servers may be numbered by thousands, and some have 

 attained an eminent reputation. At the present day, in 

 Germany, England, France, and the United States, the 

 most careful and elaborate investigations are being made, 

 older observations are repeated and corrected, new discov- 

 eries are rapidly announced, and the most hidden recesses 

 of nature are being explored. 



It is proposed in this treatise to give such a resume of 

 microscopy as shall enable the student in any department 



