CHAPTER VII. 



For this class of work we have in the preceding pages- 

 unhesitatingly expressed our preference in favor of ob- 

 jectives of the widest aperture. Such are the instru- 

 ments we ourselves use daily, and can confidently recom- 

 mend to all who may be desirous of working with the 

 best instrumentation obtainable. Therefore, whatever 

 we may have to offer in the way of instructions sug- 

 gested by the above heading will be solely applicable 

 to the class of objectives generally known as " wide- 

 angled," to which we have given in the past, and pro- 

 pose yet to give in the future, a large amount of careful 

 study and attention. And first of all it becomes neces- 

 sary to disabuse the mind of the student of some of the 

 popular fallacies which have found outlet and circulation, 

 through the medium of the microscopical periodical 

 literature of the present and past few years. These, as 

 will be discovered by the attentive observer, are par- 

 oxysmal in their nature ; in fact are veritable " chateaux 

 en espagne," at once inconsistent in detail, and roundly 

 absurd when contemplated as an entirety. Thus it oc- 

 curs that at one moment the student is taught that wide- 

 angled glasses are extremely inconvenient; that great 

 attention has to be bestowed on the adjustment and illu- 

 mination, etc. ; while on the other hand, another " au- 



236 



