26 Tlie Use of a Simple Microscope. 



that loicness of cost does not imply cheapness, and should he one 

 of the last things thought of in purchasing a microscope, as a 

 certain amount of (jood loorkmanskij) is absolutely indispensable, 

 and a stand lacking this, would after a very short time become 

 useless. 



Hints to Students. 



When an instrument has been selected, the next step will be to 

 learn how to use it. There is one thing which must be constantly 

 borne in mind from the very first, which is never to touch the 

 fjlasses ivith the jingers, nor to wipe them with anything hard or 

 rough : they should be brushed with a dry cainel-hair pencil 

 when dusty, but when they require to be wiped, this should be 

 done with a piece of clean and very soft washleather, kept on 

 purpose, and carefully wrapped up from dust when not in use. 

 The use of the various pieces of apparatus will be best learned 

 by obtaining a half-hour's instruction from an old hand. The 

 method of observing must be gained by practice after the student 

 has been put into the right way. 



It is a well known fact that persons not accustomed to observe 

 minutely see nothing distinctly on first looking into a micro- 

 scope — that is, although they may see the whole contour of the 

 object presented, they take only a general view of it, and are not 

 impressed with any special definite fact, such as could be 

 referred to from memory afterwards, as a distinctive character- 

 istic. There is the greatest difference possible between seeing 

 and observing. Seeing is the rule, and observing the exception. 

 Place a piece of lichen-covered stone or wood in the hands of 

 a dozen different persons, and it is more than probable that not 

 one of them, ten minutes afterwards, would be able to say whether 

 it was red, blue, yellow, or green. Now, it is this habit of 

 observing minutely and attentively, Avhether it be with the 

 common eye-glass or with the highest powers of the microscope, 

 that is the first step to be attained. Some particular feature 

 should be looked for, such as external shape, roughness or 

 smoothness of surface, colour or peculiarity in form of markings, 

 &c., &c,, and afterwards the same features should be looked for 

 in other kindred bodies, and the differences noted arid ivritten down 

 if possible. 



By so comparing objects one with another, and looking out for 

 minute and trifling differences of structure, the faculty of observing 

 — of detecting slight distinctions and of taking in, almost at a 

 single glance, all the leading features of an object — may be rapidly 

 gained if set about in the right manner. When once it has 

 become a habit, a solid foundation is laid for reliable results to be 

 drawn from subsequent investigations. A careless and faulty 



