JOURNAL 



OF THE 



Royal Horticultural Society. 



Vol. XVI. 1893. 

 Part I. 



ON THE EFFECTS OF URBAN FOG UPON 

 CULTIVATED PLANTS. 



The Second Report presented to the Scientific Committee of 

 the Royal Horticultural Society, February 14, 1893, 



By Professor F. W. Oliver, M.A., D.Sc. 

 (With the assistance of Professor F. E. Weiss and 

 Miss M. F. Ewart). 



[Note. — In the work of this investigation, of which this is the 

 second report, I have become indebted for assistance and 

 advice to many persons. Till March of last year I received 

 the unstinted support of my assistant at University College, 

 Mr. F. E. Weiss. It had been my intention that he should 

 share with me all the responsibilities of the work, but his 

 translation to the Chair of Botany at the Owens College, 

 Manchester, has rendered the realisation of this intention im- 

 practicable. I cannot, however, let this opportunity pass 

 without expressing my appreciation of his services. To my 

 former pupil, Miss Ewart, B.Sc, I am greatly indebted for her 

 share in the examination of injured tissues and help generally 

 upon the experimental side of the investigation. I owe my 

 hearty thanks to Dr. Edward Schunck, F.R.S., for the assist- 

 ance which he has willingly rendered upon points requiring 

 the knowledge of an expert in the spectroscopic investigation 

 of chlorophyll and its derivatives. Dr. G. H. Bailey, who 

 is associated with the Manchester investigation, has been 



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