Microscopical Essays. 



the fame with the under fide. When the (km is taken off on 

 both fides, wafh out the pulpy matter, and the fibres will be ex- 

 hibited in a beautiful manner. By flitting the ft a Ik you may 

 feparate the anatomized leaf into two parts. The fkins that are 

 peeled from the fibres will alfo make a very good object. The 

 autumn is the befl feafon for the foregoing operation, as the fibres 

 of the leaves are much ftronger at that feafon, and lefs liable to 

 break. 



Ores and minerals fhould all be carefully wafhed and brufhed 

 with a fmall brufh, to remove any extraneous matter that may ad- 

 here to them. Shells may be ground down on a hone, by which 

 their internal ftru&ure wifl be difplayed. 



To VIEW THE CIRCULATION AND EXAMINE THE PARTICLES' 



of the blood. The principal point the obferver muff aim at, 

 in order to view the circulation of the blood, is to procure thofe 

 fmall animals or infecls that are moll tranfparent, that by feeing 

 through them he may be enabled to difcover what paffes within 

 them. The particular kinds beft adapted for the purpofe will be 

 enumerated in the defcriptive catalogue at the end of this work. 



If a fmall eel is ufed for this purpofe, it mufl be cleanfed from 

 the flime which covers it ; after which it may be put either in the 

 fifh-pan, or a glafs tube filled with water, and then placed under 

 the microfcope. If the eel is fmall enough, the circulation may 

 be viewed in the molt fatis factory manner. Leeuvenhoeck has 

 given, in his 112th epillle, an accurate defcription of the blood- 

 veflels in part of the tail of an eel. The fame figure may alfo be 

 feen in my father's Treatife on the Microfcope. The tail of any 



other 



