TJie Microscope Unpacked. 19 



as the materials are (I quote from the Rev. T. W. 

 Webb's book on the Telescope), scratching is an easy 

 process ; and the result of ordinary wiping may be 

 seen in an old spectacle-glass held in the sunshine/' 

 completely covered with scratches; surely the most 

 valuable part of a good microscope deserves better 

 treatment. 



