CORRESPONDENCE. 43 



Mr. Hickie does not seem to believe in anything else but German 

 objectives. I very much doubt if he has ever looked through some 

 of the fine Powell and Lealand's objectives (we know he does not 

 approve of their eye-pieces), above all those made on their new 

 formula ? ! ! 



What feats would Mr. Hickie accomplish should he use Powell 

 and Lealand's ^nes^ objectives, and their achromatic condenser ? 



Perhaps he might succeed in superseding the performance of his 

 German object-glasses, and his straight candle-light, and favour us 

 with some more of his startling discoveries ! ! ! 



I am, Sir, your obedient servant, 



M. J. GOEDON. 



Professor Hasert's New Objective. 



To the Editor of the ' Monthly Microscopical Journal.'' 



19, MoNTPELiER Place, Brighton, November 10, 1875. 



Sir, — Your readers will peruse with interest Mr. Hickie's report 

 on the glass above referred to. 



Whatever else it may do, this new glass seems calculated to cause 

 a reconsideration of some views very generally current. For in- 

 stance, Mr. Hickie, speaking of its definition, gives it his unqualified 

 admii-ation ; and says, " I seem to myself never to have known what 

 the word definition really meant till I saw this glass, so beautifully 

 clear, sharp, and distinct were all the details. I certainly never saw 

 any objective that even approached it." 



And yet it appears that the lens will not bear deep eye-piecing ! 

 Indeed its conduct in this respect, according to Mr. Hickie's account, 

 though not in his words, is nothing less than very bad. 



But if there is one thoroughly accepted idea connected with 

 lenses, it is that deep eye-piecing is, above all, the surest test of their 

 correction. So that we have here a contradiction. Mr. Hickie ex- 

 plains by saying that he " came to the conclusion that there is ample 

 room for improvement in our eye-pieces." No doubt ; but whatever 

 their demerits, they are as fair a test for one lens as for another 

 of like power ; and the fact remains that this Hasert objective, though 

 it defines with extraordinary precision, bears deep eye-pieces much 

 worse than the general run of glasses. 



The facts relating to the screw-collar are very remarkable ; but 

 under the circumstances, I cannot think with Mr. Hickie that the 

 absence of that apparatus will be an insuperable objection in England ; 

 besides, if these glasses are really good enough to induce English 

 opticians to make them, they will no doubt be furnished with screw- 

 collars, to meet extreme cases ; a great advantage, though everybody 

 will appreciate the comfort of not being ordinarily obliged to use 

 them. 



On the subject of penetration, working histologists will be very 

 disappointed in the vagueness of Mr. Hickie's report; hence I beg 



