HINTS TO STUDENTS ON PRACTICAL WORK 



Use of the Microscope. 



(i) Remember that the microscope is a delicately 

 adjusted scientific instrument, and must not be treated 

 roughly. Do not lift it by the tube, but always by 

 the solid part of the stand. 



(2) Take great care not to get liquids of any kind 

 on to the lenses. If a lens is dusty, wipe it with a soft 

 handkerchief. 



(3) Always see that the slide and coverslip are 

 perfectly clean before use. 



(4) If you cannot then get a clear view of an object, 

 look first to the surfaces of the lenses, especially of the 

 objectives. If there is glycerine on the surface of the 

 lens, it must be carefully and repeatedly wiped with 

 a soft handkerchief. Breathing on the lens between 

 wipings will often help. Take care never to scratch 

 the lenses. This is often done by rubbing with a harsh 

 cloth. 



(5) In examining an object or section under the 

 microscope look at it first with the naked eye, then 

 with a hand lens, then with the low power, and finally 

 with the high power. This procedure enables you to 

 get a preliminary idea of the general form of the object 

 or section, before you look at its details, and thus to 

 relate the details to the larger features of its structure. 

 Remember that the world you see under the micro- 

 scope is not really a different world from that which 



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