ARTIFICIAL LIGHT. 199 



My visitor was delighted, nor did he attempt to con- 

 ceal his delight. " Now," said he, "just keep all things 

 just as they are, but take off your glass and put on 

 mine." The same was accordingly done, and the result 

 was that we could not see the diatom at all, nor could 

 we, by the best possible manipulation of the lamp, see 

 it well enough to recognize it. I suggested the possi- 

 bility that the glass might not be truly centered, and 

 thus to some extent be defeated. Attention was there- 

 fore given to this, but without avail. My friend's ob- 

 jective positively refused to have anything to do with 

 the reflex illuminator. 



Now, I have found, by countless experiments, that of 

 two objectives, the one working well with the genuine 

 " reflex," and another refusing to so work at all, the 

 former will be far the superior glass for any and all 

 work; a fact which, after a little subsequent experi- 

 ment my visitor was not slow to accept. I am of course 

 referring to objectives generally known under the ap- 

 pellation of " high powers." 



Thus it will be seen that the Wenham " reflex " is for 

 any of these purposes quite a handy and effective little 

 instrument, and ought to have its place in the accessory 

 box of every microscopist. It will serve, too, in its 

 legitimate capacity as designed by its inventor, i. e,, as 

 a fc ' dark ground illuminator;" but herein will be found 

 its* least value. To return directly to our subject: I 

 cannot too strongly recommend that every one inter- 

 ested in microscopical work requiring the employment 

 of high amplifications with fine defining power, should 



