The microscope ought not to stand continually ex- 

 posed to direct sunlight. 



When removing the microscope from the case, or in 

 handling it in the laboratory, do not grasp it by the arm 

 (see frontispiece), which is actuated by the delicate fine 

 adjustment. Grasp it by the pillar below the stage or 

 by the stage just where the pillar joins it. The best 

 modern instruments are provided with a new fine ad- 

 justment at the side, permitting the introduction of a 

 handle by which the microscope can be easily handled. 

 All rough handling is so out of harmony with the. use of 

 such a delicate instrument that it is unnecessary to 

 caution against it. 



Finger marks on the highly polished surfaces should 

 be removed immediately with a soft cloth or clean cham- 

 ois skin. If they do not remove easily, breathe on the 

 surfaces and rub gently. If allowed to remain for any 

 time they are removed with great difficulty. If the sur- 

 faces become soiled with material which gentle rubbing 

 will not remove, dampen a cloth with water and rub 

 gently. If this will not remove it use a very little 

 xylol, ether or chloroform, being careful not to rub too 

 hard, and to dry as soon as possible. Never use alcohol 

 on lacquered parts. It will dissolve the lacquer, no 

 matter how dilute it is. When the lacquer is gone 

 nothing can be done for it outside of the factory. All 

 reagents should be kept from the lacquer wherever pos- 

 sible. On most of the better modern microscopes the 

 more exposed parts are so finished that they are not 

 seriously affected by any of the above mentioned rea- 

 gents, with the exception of the strong acids. All such 

 reagents should be removed as soon as possible. This 

 finish is generally a black enamel or a gray or black 

 plating. Sometimes this finish is extended to the upper 

 parts of the stand. 



