Microscopical Essays. 



be taken from it's place at K, and fitted on a clamp, by which it 

 may be fixed to any part of the table A B. 



To use the Dissecting Table. 



Let the operator fet with his left fide near a light window ; the 

 inftrument being placed on a firm table, the fide DH towards the 

 ftomach, the obfervations fliould be made with the left eye ; this 

 pofition is well adapted for obferving drawing or writing. In 

 diflecting, the two elbows are to be fupported by the table on 

 which the inftrument refts, the hands refting againft the board 

 AB; in order to give it greater {lability, (as a fmall (hake, 

 though imperceptible to the naked eye, is very vifible in the 

 microfcope) the differing inftruments are to be held one in each 

 hand, between the thumb and two fore-fingers. Other cireum- 

 flances will be learnt from practice ; and more will be faid on the 

 mode of difiecting fmall objects in the following chapter. 



Description of Dr. Withe ring's Botanical Microscope, 

 Fig. i, Plate VI. 



This little inftrument is reprefented at Fig. i, Plate VI. It con- 

 fifts of three brafs plates, A, B, C, which are parallel to each 

 other ; the wires D and E are rivetted into the upper and lower 

 plate, which are by this means united to each other ; the middle 

 plate or ftage is moveable on the aforefaid wires, by two little 

 fockets which are fixed to it. 



The 



