C 26 ] 



often leads either to inattention or injudicious prac- 

 tices in the tenant or the bailiff. tc Agrum pes- 

 nmum mulct art cnjus Dominus non docet sed audit ml- 



There is no idea more unfounded than that a 

 great devotion of time, and minute knowledge of gen- 

 eral chemistry is necessary for pursuing experiments 

 on the nature of soils or the properties of manures. 

 Nothing can be more easy than to discover whether a 

 soil effervesces, or changes colour by the action of an 

 acid, or whether it burns when heated ; or what 

 weight it loses by heat : and yet these simple indica- 

 tions may be of great importance in a system of culti- 

 vation. The expence connected with chemical enqui- 

 ries is extremely trifling ; a small closet is sufficient 

 for containing all the materials required. The most 

 important experiments may be made by means of a 

 small portable apparatus ; a few phials, a few acids, a 

 lamp and a crucible are all that are necessary, as I shall 

 endeavour to prove to you, in the course of these 

 lectures. 



It undoubtedly happens in agricultural chemical 

 experiments conducted after the most refined theo- 

 rectical views, that there are many instances of failure, 

 for one of success 5 and this is inevitable from the 

 capricious and uncertain nature of the causes that 

 operate, and from the impossibility of calculating on 

 all the circumstances that may interfere ; but this is 

 far from proving the inutility of such trials ; one hap- 

 py result which can generally improve the methods 

 of cultivation is worth the labour of a whole life ; and 



