MANURES. 109 



empirical, inasmuch as the substances experimented with are of 

 unknown fertihzing value. The " phosphates " or bone mix- 

 tures usually possess no uniformity in composition. One farmer 

 may be lucky enough to secure a barrel or two of the substances 

 in which a considerable amount of plant-nutriment is found ; 

 another may purchase packages of the same brand which are 

 almost wholly destitute of the phosphatic or nitrogenous ele- 

 ments, and are therefore practically valueless. These, employed 

 in the usual empirical way, of course give varying results — 

 results which are better calculated to confuse and perplex than 

 to instruct. 



But if the fertilizers we employ are honest mixtures, and 

 have a fixed value, how much positive practical information 

 can we gain from applying them in a small way, in our fields, 

 without taking into account some important considerations 

 which are usually overlooked ? It is true, if we thrust the 

 " raw bone " into the hills of one row of potatoes, and leave the 

 next one without the mixture, we can measure and weigh at 

 harvest time, and thus obtain results from which to form wise 

 conclusions or dogmatic opinions. These results, however, 

 must be regarded as blind guides. Any experiments in hus- 

 bandry which do not extend over a period of time exceeding 

 one or two seasons, and which do not take into account varia- 

 tions in soils and meteorological conditions, are practically 

 worthless. It appears to your Committee high time that the 

 intelligent farmers of Essex abandoned the " irregular," uncer- 

 tain, empirical methods of experimenting with fertilizers, and 

 adopted a form better calculated to advance true knowledge in 

 respect to the greatest interests of agriculture. In the first 

 place, the materials experimented with should be definitely un- 

 derstood. In phosphates, the exact percentage of soluble phos- 

 phates of lime contained in the fertilizer should be known, and 

 also the amount of free ammonia, or ammonia-forming constit- 

 uents. If substances containing potash or soda are employed, a 

 knowledge of the exact percentage of these alkalies also should 

 be had. With the best and most appropriate materials in our 

 hands, we do not obtain in one or two seasons even a proximate 

 knowledge of how much actual value they may be to our crops. 

 A dry season may prove entirely unfavorable for the appropri- 

 ation by plants of any one element or compound, or a wet 



