1895 THE MICROSCOPE. 57 



of others, the looking for an object while focusing down 

 toward it is far from safe ; at least, that is the result of 

 the writer's observation during thirty-eight years of con- 

 tinuous and earnest attention to microscopy. But an inch 

 objective is used far away from the slide, and at a per- 

 fectly safe distance ? So is a three-inch, several times 

 as far away ; yet the writer has seen a highly cultivated 

 man and experienced microscopist, in the midst of his 

 best years, drive a 3-inch objective, with a crash that 

 was heard throughout the room, through a unique and 

 priceless slide — belonging to somebody else. But he was 

 a stupid blunderer ? Well, that is what he said, with 

 manifest disgust and contempt, and he ought to know ; 

 in fact he abjectly announced his resolution to devote 

 the blighted remainder of his worthless life to the fitting- 

 penance of eating all the -'humble pie" that the spectators 

 would condescend to prepare for his sanctification. But 

 this is the world we are living in at present, and such 

 acts of farce-tragedy are common enough to recur to any- 

 body; as evidently they did to Dr. S. when he wrote of 

 a tin cell that was too thick to be pleasing. "However, 

 the cell serves one good purpose; the diatoms cannot be 

 crushed between cover glass and slip unless a very strong- 

 hand is wielding the coarse adjustment." 



The only safe rule that can be followed without being- 

 sorry sooner or later, is, never to find the object by focus- 

 ing downward, and, 7iever to allow anyone else to do it 

 with your apparatus or objects. If one must focus down- 

 ward, which seems temptingly easy, but in the end is the 

 most difficult and tedious way he should do it with his 

 own things; so as to make sure of the benefit of the 

 scolding which politeness will hardly prevent his giving 

 to himself when the first (and last ?} accident happens. 



This method of finding the object is applicable to even 

 moderately high powers, of moderate angular apertures; 

 using the foreign particles too freely present on the top 



