SOMETHING FURTHER ABOUT OBJECTIVES. 113 



The preceding quotations are thus presented to the 

 reader because the issue we have under consideration is 

 therein discussed typically (I may say) from both the 

 American and English standpoints. To the testimony 

 cf these talented gentlemen the author could, did his 

 space allow, add a mass of similar evidence. 



I repeat it is not consistent with the limits of this 

 little book to further discuss the issue in question. The 

 author therefore dogmatically asserts that his positions 

 taken in public print relative to the matter we have 

 been considering, were then correct, and have so re- 

 mained up to the present date. 



But mark this point: the claim thus established in 

 favor of i4 medium powers" of the widest apertures 

 has no reference whatever to hosts of objectives made 

 and sold with high-sounding figures attached. Keep 

 this fact in lively remembrance. 



We are now prepared to return directly to the point 

 from which we started. We have seen by our digres- 

 sion that the relations existing between the inch and 

 the one-fiftieth are to be essentially modified, relatively, 

 as to the nature and performance of a one-sixth as 

 compared with that of a one-fiftieth. For instance, if 

 it were true, as has formerly been accepted, that it is 

 the province of the inch to assist in the study of the 

 simpler organisms, and that of the fiftieth for the in- 

 vestigation of the most delicate structures, it does not 

 hold good at this present writing that a one-sixth or 

 tenth (generally classed as medium powers) are the 

 proper objectives for an intermediate class of work only. 



8 Microscopy. 



