MEMOIR OF SWAJf.MERDAM. 55 



all his predecessors in the same field of labour ; and 

 this feeling we are in some measure enabled to gra- 

 tify by the care of his biographer, Boerhaave, whose 

 account is so satisfactory, that we cannot do better 

 than nearly translate his own words. For the dis- 

 section of very minute objects, he had a small brass 

 table, ingeniously constructed by an artist of Amster- 

 dam, to which were attached two moveable brass 

 arms. The upper part of these arms was so planned 

 as to admit of a vertical motion, so that the operator 

 could adjust their height to answer his purposes ; one 

 of them was designed to hold the object under exa- 

 mination, the other, the glasses through which it was 

 to be viewed. These glasses were, of course, in grea t 

 variety, as well as the manner in which they were 

 fitted up into microscopes, and it was always a matter 

 of great anxiety with Swammerdam to obtain them 

 of the best possible substance and workmanship. It 

 was his practice first to view the object under exami- 

 nation through a glass of comparatively small power, 

 and to apply stronger ones gradually as he was be- 

 coming more familiar with its forms and appearance, 

 a practice by which every observation was made 

 subservient to the next, and the deceptive tendencies 

 of different lights in a great measure guarded against. 

 His skill and patience in constructing cutting instru- 

 ments were remarkable, and it is, in a great degree, 

 to their ingenious forms, and extreme delicacy, that 

 much of his success is to be ascribed. His scissors <, 

 were remarkably fine and sharp-pointed, and this 

 was a favourite instrument with him, as he found it t 



