Mr. Brooke on Deep Objectives. 51 



MR. BROOKE ON DEEP OBJECTIVES. 



We have received the following from Charles Brooke, Esq., 

 F.R.S., President Microscopic Society London: — 



" My attention has recently been directed to some remarks 

 contained in p. 329 of your June number, alleging a discre- 

 pancy between a statement of mine, contained in my report on 

 the microscopes in the late International Exhibition, that ' no 

 objective yet manufactured for sale at all rivals in its power 

 of development the ^th of Messrs. Powell and Lealand •/ and 

 another statement, contained in my presidential address, de- 

 livered at the last annual meeting, that ' I have not hitherto 

 succeeded in developing any point of organic structure with 

 Powell's ^th that is not equally visible with a ^th by Ross.'' 

 This apparent contradiction has no real existence, inasmuch as 

 the gth by Ross to which I alluded (a great improvement on 

 any previously made by him) ivas not in existence at the time to 

 Avhich the former observation refers ; and in corroboration of 

 my own opinion I may further state, that after having succes- 

 sively examined, together with Dr. Beale, with this -^th, and 

 with his own ^ 3 th (or ^th), several difficult preparations of 

 tissue, with which he was well acquainted, he remarked that 

 c he did not think he had ever seen some points of structure 

 better shown than they were by my j^th/ 



" In the following page, 330, the writer asks, ( When an 

 object (other than diatom lines) has been seen with an -|th or ^th, 

 can it not nearly always be shown by the Isth. V To this I 

 answer, emphatically, no, in regard, for example, to the 

 minute structure of nerve-tissue ; and in this opinion I am 

 fully borne out by the observations of Dr. Lionel Beale, who 

 has probably done more good work with his ~th than any 

 other observer. — I am, Sir, your obedient servant, 



" Chas. Beooke. 



,! 16, Fitzkox Square, July lUh, 1864." 



