12 On tht Photographic dilintation [No. 9, new isbhi. 



what I have been able to learn, to be still the general practice in 

 England. The only exception I know of, being the Rev. W. T. 

 Kingsley, whose paper upon the subject of Micro-photography, read 

 to the Society of Arts, will be found in No. 8 of the London 

 Photographic Journal. 



Mr. Kingsley' s name is well known to Microscopists as that of 

 the inventor of a Condenser which bears his name, and he has, I 

 believe, some reputation as a scientific man, and it appears to me 

 very probable, that the complicated additions he thought it neces- 

 •ary to introduce has done much to deter people from the practice 

 of Micro-photography, of which we now very rarely hear any 

 thing. In his paper he describes as necessary, 



1st. A set of collecting lenses. 



2nd. A set of condensing lenses, of which a separate set was 

 to be provided for each power ; although of no use for any other 

 purpose. 



3rd. Object glasses very much under-corrected for colour, 

 leaving a strong red fringe, using with these a positive eye-piece 

 with an additional (bi-convex) lens to the Field glass. — The 

 Microscopic object glass is over corrected for colour, this over- 

 correction being rectified by the Huyghenian, or under-corrected, 

 (i. e. non-corrected) Negative eye-piece. 



The foregoing and some other complications, which I have not 

 adverted to, were, if not totally unnecessary, certainly sufficient to 

 deter the majority of Photographers from attempting what appear- 

 ed so difficult. 



The illumination of an object when high powers are used is 

 doubtless somewhat difficult, and Mr. Kingsley's condensers 

 would not be objectionable were they achromatic and less expen- 

 sive ; but why he meddled with the optical part of the Microscope 

 itself is to me a mystery, for I find that Ross's Microscope when 

 used with the Huyghenian eye-piece is in the best possible state 

 of correction for Photographic purposes, the visual and actinic 

 foci being absolutely coincident. In a case of this kind an ounce 

 of proof is better than a ship load of argument, and when I say 

 that the pictures I exhibited, and some of which I have brought 

 for examination were taken at the best visual focus I could ob- 



