DONT'S 



Don't allow dust and dirt to settle on the microscope. 



Don't carry the microscope by the arm. 



Don't use alcohol on the microscope. 



Don't expect too -great a range in the fine adjustment. 



Don't take the fine adjustment apart. 



Don t bring the objective into contact with the cover 

 glass. 



Don't fail to focus up before turning the nosepiece 

 unless you know the objectives are parfocal. 



Don't forget that high powers have short working dis- 

 tances. 



Don't focus down with the eye at the eyepiece. 



Don't fail te secure good, even illumination. 



Don't drop the objectives and oculars. 



Don't try to take an objective apart. 



Don't try to work with dirty lenses. 



Don't try to clean them with a dirty cloth. 



Don't fail to clean oil from an immersion lens im- 

 mediately after using. 



Don't try to work with an immersion lens when there 

 are air bubbles in the oil. 



Don't use high powers when low ones will do. 



Don't use higher oculars than necessary. 



Don't expect a lens to work at its r/est unless used on 

 a cover thickness, and with a tube length, for which it 

 is corrected. 



Don't shut one eye. 



Don't get discouraged if desired results do not come 

 immediately. 



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