The microscope and its parts. 25 



It always adds a zest to this work if the worker can 

 make his own topis, and especially if he can prepare 

 his own objects. Almost every tool needed at the be- 

 ginning can be made at home. Slides must be made 

 at home if one desires to examine any of the endless 

 variety of invisible animal and vegetable life with 

 which the great world teems. All the objects referred 

 to in this book can be studied when only temporarily 

 mounted; indeed, no method of preserving some of 

 them has yet been discovered or invented. They 

 must, therefore, be studied alive or not at all. And 

 for the beginner this is not only the easiest, but it is 

 the most instructive and inspiring way. 



Some things can be examined when dry. Such an 

 object is simply laid on a slip, placed under the spring 

 clips, and the low-power objective used. The ripe 

 seeds of wild plants are easily studied in this way, and 

 some of them are marvellously beautiful. Small 

 insects can also be looked at when dry, but the result 

 is not always entirely satisfactory unless they are 

 viewed as opaque objects. Usually most objects 

 appear better and show more of their structure, if ex- 

 amined under a disk of thin glass and surrounded by 

 water. But seeds, scales from butterfly's wings, and 

 many other things, can be viewed and preserved in 

 a dry state by enclosing them in a cell with a thin- 

 glass cover fastened above. This "cell" and "cover" 

 and fastening process will be described presently. 



All plants and animals living in water must be 

 examined in water. To dry them and expect to learn 

 anything about them, or even to obtain a correct idea 

 of their true appearance, is a waste of time, and worse. 

 When your wet specimens get dry on the slide, and 



