28 THE SCIENTIFIC PRINCIPLES 



vegetation, and that, as this store was gradually used 

 up, the soils became poor. 



Although, as has been said, the lectures which 

 have been given by the Sibthorpian Professor of Rural 

 Economy commenced almost simultaneously with the 

 appearance of Liebig's first work, and many of them 

 had direct reference either to Liebig's own views, 

 or to current discussions relating to them, their in- 

 auguration was prior to, and quite independent of, 

 the interest excited by that work. Not so was it, in 

 the case of many other agencies for promoting know- 

 ledge in regard to the scientific principles of agri- 

 culture, both in this country, and on the Continents 

 of Europe and America. I think too, I may safely 

 say, that the stimulus was earlier felt, and was 

 earlier productive of results, in this country, than in 

 Liebig's own, or elsewhere. 



In 1843, the Royal Agricultural Society of England 

 first appointed a consulting Chemist ; Dr., now Sir 

 Lyon Play fair, being the first holder of the office. 

 In 1848, the late Professor Way was elected, and 

 the Society's journals of that time bear testimony 

 to his clear perception of the agricultural problems re- 

 quiring solution, and of his capacity as an investigator. 

 In 1858, Dr. Voelcker succeeded to the office, and 

 continues to hold it with much advantage to that 

 union of f Practice with Science/ which the Society 

 by its motto recognises as so essential to progress. 

 Thus, after having been Professor of Chemistry at 

 the Royal Agricultural College, Cirencester, for many 

 years, Dr. Voelcker has now been consulting Chemist 

 to the Royal Agricultural Society of England for 

 more than a quarter of a century ; and to some of 

 the results of his investigations I shall have to refer 

 on future occasions. 



