4 MICROSCOPY FOR BEGINNERS. 



specimens and the thousand and one objects that attract 

 the attention on every summer ramble. 



The writer personally dislikes the combination pock- 

 et-lens formed of two or three separable glasses. If but 

 one lens of the combination is wanted for immediate 

 use, the entire number must be pushed out of the thick 

 and awkward case, one must be selected and separated, 

 for the perverse thing usually comes out of the pocket 

 upside down, and it is of course desirable that the high- 

 est-power glass shall be next to and nearest the object, 

 while those not needed are turned to one side, making a 

 series of operations that take time, both hands, and con- 

 siderable patience if you are anxious to examine the 

 specimen. Your companion will have finished the work 

 with the single glass, and will be telling you how the ob- 

 ject looks, before your complicated affair is ready to be- 

 gin, provided you are not wise enough to have avoided 

 the combination pocket-lens. And if tire whole number 

 is used at once, the working distance is usually so short 

 that the observer's head or hat-brim shuts off most of the 

 light, so that the object can be seen with difficulty, and 

 a very little of it at that. To see at one view so small a 

 portion as these high-power combinations always show, 

 and to be compelled to pass the lens over so many little 

 parts before an idea of the whole surface can be ob- 

 tained, is, to say the least, not satisfactory ; unless the 

 observer is familiar with the entire object, and the rela- 

 tion and arrangement of all the parts, a low-power pocket- 

 lens is the most useful, and the one to be recommended. 



