OF AGRICULTURE. 25 



So far, I have endeavoured to convey some idea 

 of the state of knowledge bearing upon the scientific 

 principles of agriculture, prior to the appearance of 

 Liebig's first two works on the subject; and also 

 briefly to summarise the views he then enunciated 

 in regard to some points of chief importance. I will 

 now attempt briefly to indicate what progress has 

 been made since that period, largely at any rate due 

 either to the direct influence of his teaching, or to 

 the stimulus given to enquiry by the discussions 

 which his writings called forth. 



It is a coincidence of some interest, that the first 

 lectures given by the Sibthorpian Professor of Kural 

 Economy in this University, were delivered by my 

 predecessor, the late Dr. Daubeny, almost contem- 

 poraneously with the appearance of Liebig's first 

 Work, in 1840 ; one of a course of three having been 

 given before, and two within a few months after, the 

 publication of that work. These lectures were after- 

 wards published, and, in his preface, Professor Daubeny 

 expresses his indebtedness to Liebig's Work for some 

 of the fundamental doctrines, and for some of the 

 details embodied in his expositions. 



In the lectures in question, Professor Daubeny 

 discussed the importance of the study of botany, 

 physiology, and chemistry, in the elucidation of agri- 

 cultural practices. He contrasted the conditions of 

 cultivation in the case of virgin soils, with those in 

 long-settled countries. He treated of the sources 

 of the constituents of our crops, of fallowing, manur- 

 ing, and rotation, so far as the knowledge of the 

 day permitted. 



Finally, Dr. Daubeny put forward some specu- 

 lations as to the origin of the constituents of the 

 first vegetation on the surface of the globe, and 



