i|lkr0SC0|jit Vision. 



By Edward M. N'elson, P.R.M.S. 

 {Read March 2Gth, 1897.) 



BEFORE beginning the subject for this evening, I 

 wish to thank you for the great honour your Presi- 

 dent's kind invitation has conferred upon me in selecting 

 me as an exponent of this later development of microscopy. 

 It will be generally conceded that this development owes 

 its inception to Prof. Abbe's unrivalled mathematical and 

 physical researches in the optics of the microscope, which 

 were first brought to the notice of microscopists in this 

 country by your fellow-citizen, the late Dr. H. E. Fripp, 

 whose translations of Prof. Abbe's original papers were 

 published in the Proceedings of the Bristol Naturalists^ 

 Society in 1875, new series, vol. i. p. 200. A rather full 

 extract from Dr. Fripp's translations appeared in the 

 Monthly Microscopical Journal of the same year.* 



Two years later they attracted the attention of Mr. J. 

 W. Stephenson (late Hon. Treas. R.M.S.), who, just twenty 

 years ago, brought the subject again before the R.M.S. And 

 in the following year, 1878, Mr. F. Crisp (late Hon. Sec 

 R.M.S.) read a paper to the same effect before the Quekett 



* To Dr. Fripp the microscopical world is also indebted for the 

 translation of Prof. Helmholtz' paper on the " Limits of the Optical 

 Capacity of the Microscope," Monthly Microscopical Journal, vol. xvi. 

 p. 15 (1876). 



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