The Microscope Unpacked. 11 



object ? Not quite; we must arrange for throwing 

 light on the object, for that is a great and important 

 part of the microscopist's craft. You cannot carry the 

 small objects you examine close to the lamp, to 

 examine their surfaces, or hold them between your 

 eyes and the light with a view of seeing their interior 

 structure; but you can bring the light down upon 

 them with what is called the " bull's-eye," or conden- 

 sing lens, (Plate I., fig. 1, C,) or you can send light 

 through them with a mirror (B). You will find both 

 packed somewhere, the condensing lens perhaps fit- 

 ting into the case, and the mirror perhaps already 

 attached to the stand. Daylight or lamplight are both 

 suitable for the use of the microscope, but many an 

 observer finds evening hours to be the only leisure 

 time. Fortunately the observation of objects by 

 lamplight is particularly pleasant and satisfactory. 

 Were I asked to give an opinion as to the preferable 

 light of the two, I would say, daylight for some sorts 

 of investigation, as, for instance, for ascertaining the 

 exact colours of objects; but lamplight, unquestion- 

 ably, for exhibition. 



Do not use a candle, it flickers so unpleasantly, 

 and its height changes as it burns down ; use a lamp, 

 a small paraffine or other lamp about the same size 

 will answer very well. For illuminating opaque 

 objects, you should raise the lamp on a box, or 

 something of the kind. Try what a bright little focus 

 of light you can make with the bulFs-eye lens on a 

 scrap of paper. It will be easier at first to manage 

 by leaving the microscope in its upright position than 



