THE COVER-GLASS PROBLEM 115 



this can be reversed and cemented by balsam to a thin sHde by 

 its free side, and a normal cover placed over the object, now on 

 the upper side of the old cover. 



8. On the whole, the final solution of the cover-glass problem 

 seems to the writer to be to purchase sufficient covers 0.16 to 0.17 

 millimeter thick, and to use them on all objects requiring special 

 study. 



