OF THE MICROSCOPE. 121 



Objectives. These are confessedly the most important 

 parts connected with the microscope; they therefore deserve 

 the greatest care in their selection. In a former section, we 

 fully explained the general characteristics of the different 

 kinds of objectives in market, and detailed the best methods of 

 of testing them. A careful study of that chapter will, we hope, 

 enable the beginner to avoid a glass that is absolutely bad, 

 though we must acknowledge that all experienced microscopists 

 are agreed that no amount of mere reading will enable a 

 novice to pronounce a correct j udgment upon the quality of an 

 objective, unless its defects should be very glaring indeed. In 

 this place we shall confine ourselves to a few hints in re- 

 gard to those features which adapt objectives not only to 

 special kinds of work, bat to the skill of different classes of 

 workers. For it is an undoubted fact that objectives which in 

 the hands of skillful microscopists, and on certain classes of 

 work, would give extraordinary results, would in ; other hands, 

 and for other purposes, prove of far less value than lenses of 

 what is commonly considered a greatly inferior grade. 



We do not here propose to take part in what is called the 

 "battle of the object-glasses," such a discussion being out of 

 place in an elementary work like the present, but we think few 

 will be hardy enough to deny that one who has a taste for such 

 things, but has neither the money required to purchase a first 

 class glass, nor the time necessary to acquire the requisite skill 

 to use it, had better work with a cheap French triplet than not 

 work at all. Moreover, it is astonishing how far patience, skill 

 and experience will go to make up for a deficient instrument, 

 while at the same time, it is unfortunately true that some who 

 possess the very bast glasses, and have done the most to 

 throw ridicule upon all work done with inferior lenses, have 

 never made a single contribution of the slightest importance 

 to any department of microscopical science. 



In a former chapter we discussed at length the different 

 qualities of object-glasses, and showed how these various quali- 

 ties might exist in very different degrees in different ob- 

 jectives. It is, of course, obvious that the extent to 

 which any one quality should be sought in a particular 

 glass, must depend altogether upon the kind of work that is 



