THE MICROSCOPE 51 



materials may be readily located. Cloudiness, especi- 

 ally upon the cover-slips of glycerin jelly mounts, 

 may be due to moisture, which may be removed with 

 a cloth moistened with alcohol. Dust on mechanical 

 parts is best removed with chamois or dry cloth. 

 Bearings and moving parts may be cleaned and lubri- 

 cated by wiping with a mixture of gasoline and light 

 machine oil. Fine adjustments are usually packed 

 with petrolatum. Solvents should not be allowed in 

 contact with lacquered parts. Discoloration of the 



A B 



A. With diaphragm open. B. With diaphragm partly closed 



FIG. 25. Air Bubbles. 



stage may be remedied by thorough washing and 

 drying, followed by light application of paraffin oil 

 all excess being removed by rubbing. 



Interpretation of Images. In viewing an object 

 through the microscope one must remember that the 

 image is inverted or reversed. Consequently, if one 

 moves the slide toward the right, the object as viewed 

 in the microscope will apparently move toward the 

 left. If you desire to shift an object from the edge 

 to the center of the field, move the slide in the opposite 



