60 



THE MICROSCOPIST. 



The light should be concentrated on the work by means 

 of a bull's-eye condenser, and as far as possible, the dis- 

 section should be carried on with the unassisted eye. 

 Very often the work is so fine that a magnifying glass, 

 or simple microscope, fixed to a suitable arm, will be 

 needed. A large Coddington lens, an inch and a half in 

 diameter, such as is used frequently by miners, will be 

 useful. Sometimes it is necessary to resort to the dissect- 

 ing microscope, which is a simple lens, of greater or less 

 power, arranged with rack and pinion, mirror, etc. 



The specimen may be dissected under water, in a glass 

 or porcelain dish, or a trough made of gutta-percha, etc. 

 Dr. Lawson's binocular dissecting microscope (Fig. 32) is 



FIG. 32. 



Lawson's Binocular Dissecting Microscope. 



a most useful form, as both eyes may be used. Loaded 

 corks, with sheet lead fastened to their under surface, 

 may be used to pin the subject on for greater facility in 

 dissection. Rests, or inclined planes of wood, one on each 

 side of the trough, will give steadiness to the hands. 

 Camels'-hair pencils for the removal of dust and extrane- 



