CHAIRMAN S ADDRESS. 



577 



One other point, I trust, my sketch may have suggested to you : when science, 

 a child of barely a century's growth, comes to deal with a fundamental art like 

 agriculture, which goes back to the dawn of the race, it should begin humbly 

 by accepting and trying to interpret the long chain of tradition. It is unsafe for 

 science to be dogmatic ; the principles upon which it relies for its conclusions 

 are often no more than first approximations to the truth, and the want of 

 parallelism, which can be neglected in the laboratory, gives rise to wide diver- 

 gencies when introduced into the rgions of practice. The method of science is, 

 after all, only an extension of experience. What I have endeavoured to show in 

 my address is the continuous thread which links the traditional practices of 

 agriculture with the most modern developments of science. 



The following Papers were then read : — 

 1. Impurities in the Atmosphere of Towns and their Effects upon Vegetation. 

 By Arthur G. Huston, B.A.,B.Sc, and Charles Crowther, M.A., Ph.D. 



The atmospheric impurities in different parts of the city of Leeds have been 

 investigated by collecting samples of rain for a period of twelve months (November 

 1907 to October 190S). Similar results are given for the rainfall at the Manor 

 Farm, Garforth, about seven and a half miles due east of the main industrial 

 quarter of Leeds. The samples were collected with funnels twelve inches in 

 diameter, and were representative of the whole of the atmospheric impurities, 

 both soluble and insoluble, whether actually brought down by the rain or de- 

 posited at other times. The estimations made with the samples are indicated 

 in the following table : — • 



Analysis of Bain Water, Leeds and Garforth. 

 Total for Year, November 1907 to October 1908, expressed in Pounds per Acre. 



Further investigations have been made as to the influence of the suspended 

 impurities upon the amount and intensity of the light penetrating the atmosphere 

 at the different stations. 



A three years' experiment is recorded showing the influence of acid waters 

 (including Leeds and Garforth rain) upon the growth of grass. The grasses 

 have been grown in boxes, each one foot square, and subjected to precisely 

 similar conditions with the exception of the acidity of the water supplied. 

 Observations have been made of the effect upon the yield and composition of the 



