98 CORRESPONDENCE. 



" It is supposed that nothing more is requisite for microscopical 

 investigation than a good instrument and an object, and that it is only 

 necessary to keep the eye over the eye-piece, in order to be au fait. 

 Link expresses this opinion in the preface to his j^hytotomical 

 plates : — ' I have generally left the observations altogether to my 

 artist, Herr Schmidt ; and the unj)rejudiced mind of this observer, who 

 is totally unacquainted with any of the theories of botany, guarantees 

 the correctness of the drawings.' The result of such absiu-dity is, that 

 Link's phytotomical plates are perfectly useless ; and in sjnte of his 

 celebrated name, we are compelled to warn every beginner from using 

 them, in order that he may not be confused by false views. Link 

 might just as well have asked a child about the apparent distance of 

 the moon, expecting a correct opinion on account of the child's unpre- 

 judiced views." — Schleiden's ' Principles of Scientific Botany,' London, 

 1849, p. 584. 



I should not have quoted the above, but for Dr. Pigott's evident 

 fondness for inexperienced versus practised workers, to confirm his 

 views. 



I am, Sir, your obedient servant, 



B. Daydae Jackson. 



The Woodward, Tolles, and Wenham Controversy. 



To the Editor of the ' Monthly Microscopical Journal.^ 

 Sir, — When Col. Woodward's paper appeared in your Journal, I 

 wrote the following paragraphs as a commentary ; but I deferred for- 

 warding them, that Mr. Wenham, who was principally concerned, 

 might in the first place answer for himself; and in part also from 

 knowing that substantially my observations must coincide with his. 

 As, however, I purpose making a subsequent coromunication on a 

 more advanced part of the subject, I now forward my observations as 

 made from my own point of view, so that it may be unnecessary to 

 recur to this controversy in any future communication. 



There are no errors, scientifically speaking, in Col. Woodward's 

 paper, at least such as to require notice. And as his experiments con- 

 firm the results predicted by theory, and already verified in London, 

 it may be hoped that we have now heard the last of this strange 

 controversy. 



But there is a serious error of an historical or statistical kind which 

 cannot be passed without notice. Although an " object-glass " does not 

 and cannot give more than the specified aperture, yet it is possible to 

 construct an optical machine by which an indefinitely larger angle may 

 be extracted. By a misapprehension which it is not very easy to account 

 for, Col. Woodward, and the two friends who were called in by him, 

 imagine that this latter fact was unknown to Mr. Wenham and to myself ; 

 and that the announcement of it will come upon us as a surprise. But 

 nothing could be wider of the truth. The construction which they think 

 new is old, well known here and familiar years ago — in fact, a mere 

 commonplace. But it had nothing to do with the question in dispute. 

 This question concerned not " possible " constructions, but object- 



