MEMORANDA. 67 



degree of permanent injury to the chiefly used eye, as I can 

 testify from experience. It would have been a great boon 

 to me if I could have had the Wenham Binocular thirty years 

 ago ; and, therefore, I consider it, as I have said, a duty 

 to recommend it to those who are commencing their micro- 

 scopic career. 



Now, with regard to its '^performance'^ (as the opticians 

 say), I almost fear to write all I think, lest my own words 

 (in my letter alluded to, page 201) should he retaliated upon 

 me, and I should be accused of giving a "flaming account V 

 I would, therefore, rather express my o^vn opinion in the 

 words of one of the firm of Smith, Beck, and Beck, who 

 adapted the prism, and made the brass-work, &c. He says, 

 in a letter which was privately shown to me, " I am de- 

 lighted with it. For injections it is glorious ! I do not 

 Avish to see any thing better." And, in a letter to me, 

 since sending the instrument, he writes, " I am getting to 

 like it more and more.'' The latter remark is wonderfully 

 borne out in practice ; for, as a prisoner who has long hobbled 

 in shackles is, when relieved of them, some time before he 

 comes to the full enjoyment of the natiural use of his limbs, 

 so a microscopist who has for years been in the habit of 

 poking and straining through his /ja/f-microscope with one 

 eye, while he winks and blinks, and squeezes up the other, or 

 (as I have seen multitudes do) holds down its lid with 

 his fingers, is really some time before he comes to the full 

 enjoyment of using both eyes in a natural manner. This, 

 however, is, when the eyes are good, soon surmounted ; and 

 then commences what may truly be called " the real binocular 

 delight !" 



But here an objector may put in, " Fine talking, sir ! but 

 I have heard that!, although these new-fangled double- 

 barrelled affairs may do for low powers (inches and two 

 inches, &c.), in order to exhibit ''pretty things' as a raree- 

 show for young people, &c., yet they will not do for high 

 powers, and are quite insufficient for ' test-objects' of every 

 kind," &c. 



I reply, never was there a greater mistake. The new in- 

 strument certainly has a clearer field with a low power, and 

 with the one-inch objective and lowest eye-pieces I can dis- 

 tinctly read the Lord's Prayer, which was written for me with 

 Mr. Peters's machine {' Microscopical Journal,' No. XII, p. 

 55) within a 'circle of the one fiftieth of an inch. With the 

 half-inch it is as legible as pica print. With the quarter-inch 

 I can beautifully exhibit what were, not very long since, 

 considered " high tests ;" such as the delicate markings on 



