144 BOARD OF AGRICULTURE. 



all soils is the minimum supply in the soil of any one of the 

 mineral elements which the plant requires. 



So, too, in relation to the condition of the food of plants. 

 Scientists are perfectly agreed, I think, in this matter, that 

 the materials which enter into the composition of plants must 

 always be in a certain condition before the plant can appro- 

 priate them. You may give to the soil and to the plant an 

 endless supply, without limit, of raw, coarse, undecomposed, 

 bulky material, and yet, while you do that, you give to the 

 plant but a very small quantity indeed of plant-food that can 

 be available to it. 



It can be of no sort of use in feeding the plant until this 

 coarse, raw, crude material has passed through a stage of 

 decomposition, and the elements of plant-nutrition contained 

 therein have been eliminated from the coarse material, and 

 made solvent in water. As a natural consequence, these 

 scientists believe, that if plants are fed with the right mate- 

 rials, in the right proportions, and in the proper condition, a 

 very small quantity of this material applied to the land will 

 produce as large crops, as perfect crops in all respects, as 

 immensely large quantities of coarse, crude, unprepared 

 material. In other words, scientists believe, that, so far as 

 plant-nutrition is concerned, a very small quantity of the 

 chemical materials which are the food of plants, properly 

 prepared, in a proper condition, and in proper proportions, 

 applied to the soil, will produce just as large crops, as large 

 quantities of coarse, crude, improper material, and that the 

 farmer may positively rely upon producing large crops from 

 small quantities of chemical materials, properly compounded, 

 prepared and applied. 



These, gentlemen, in as few words as I can state them, not 

 to take your time in going over the whole ground, are sup- 

 posed to be, in the main, the scientific principles of plant- 

 nutrition. The experiments at the Agricultural College, as 

 has been already stated, have been simply an attempt to find 

 if those scientific principles could be applied in practical 

 agriculture ; to see if chemical substances could be combined, 

 and if, with those substances, we could produce the ordinary 

 crops of the farm. And for this purpose, to ascertain this 

 fact, from time to time, little by little, step by step, rules 



