Advancement of Agricultural Science, 383 



turally hold land possessing every conceivable quality, and placed 

 in every variety of local and geological position, the experiments 

 undertaken by them will, it is said, be varied in a much greater 

 number of ways, and thus be more likely to instruct us, than those 

 which might be conducted within the narrow precincts of one 

 or more experimental farms. 



Now those who reason in this manner appear to me not suffi- 

 ciently to appreciate the distinction existing between the empirical 

 and the scientific method of acquiring knowledge, or, if they do^ 

 have not altogether divested themselves of the notion so deeply 

 rooted in the minds of agriculturists in general, that by empirical 

 methods alone husbandry is to be advanced. 



To show the superiority which the scientific method of arriving 

 at truth possesses over the empirical, we will suppose what would 

 happen were any new chemical compound to be offered to the 

 attention of agriculturists. No sooner had such a substance 

 become known, than, judging by past experience, it may be pre- 

 dicted that its employment would be found advantageous on some 

 soils, and useless or injurious on others, and thus an attempt to 

 define what the descriptions of land might be which it particularly 

 favoured, would follow almost immediately upon its first ap- 

 plication. Undoubtedly, such an inquiry may be carried on 

 without much apparent difficulty in the usual empirical method, 

 namely, by engaging a sufficient number of gentlemen resident in 

 different parts of the kingdom to try the effects of the manure 

 upon their own land, and to report the results to some person 

 commissioned to give them publicity. 



But it is surprising how many tentative efforts must be gone 

 through, before a knowledge can be arrived at of the real circum- 

 stances by which its failure or success in any given case is de- 

 termined. Of the experimenters, the majority present us only 

 with such a general description of the land on which the manure 

 was used, as is included under the terms of clayey, loamy, sandy, 

 or marly, in common use, to the vagueness of which I have already 

 adverted. Others, ambitious of greater precision, have perhaps 

 sent a few hundred grains of the soil to some chemist for analysis, 

 and in consequence may be able to report faithfully the propor- 

 tion of clay, silex, calcareous earth, &c., present — still, however, 

 leaving us in the dark as to the existence or non-existence of those 

 minute quantities of alkaline and saline matters, on which perhaps 

 the suitableness of the manure in question mainly depends. 

 Hence, without any fault on the part of the analyst, who cannot 

 be expected to detect such minute quantities in the small amount 

 of soil usually submitted to him for examination, it is very possible 

 that two samples which he reports to be chemically the same may 

 be benefited in a very different degree by the foreign matter 



