212 THE CANADIAN NATURALIST. [Jnne, 



exhaustible " theory to this, '' the most precious " of plant-foods, is 

 forbidden, we have still our grant of cinereal treasures to fall baek 

 on. To these, at least, the '"inexhaustible " theory does apply ; 

 for are not its magnificent conclusions before us, stated in figures 

 by its creators themselves ? 



There is in this much comfort. For, of the ammonia we need, 

 Nature supplies, after all, the major part; whereas, of the cinereals, 

 every ounce exported from the fields by man, must be by man, 

 at his own cost, restored. 



But this comfort also is snatched from us 1 Our gravely de- 

 monstrated cinereal wealth, — our "inexhaustible" treasure of 

 silica, potash, and the phosphates, turns out to be as impalpable 

 as the ammonia itself. Like conjurers' money, this treasure also 

 vanishes out of our hands, even while we are trying to count it. 



Who then deprives us of this, the remaining moiety of our 

 agricultural fortune ? Can it be that the theorists who gave it 

 us, themselves also take it away ? It is even so. The promulga- 

 tors of the grand doctrine of cinereal affluence, caution us not to 

 act on it. They tell us that they do not adopt it " in practice '^ 

 for their own guidance ; and we learn with sorrow, from their 

 own pre-cited paper, the disastrous issue of an attempt, continued 

 during eighteen years to carry it into effect : — 



" They [the authors of the paper] had grown wheat for eigh- 

 teen years consecutively on the same land, respectively without 

 manure, with farm-yard manure, and with different constituents 

 of manure, and they had determined the amounts of the different 

 mineral constituents taken off in the crop from the respective 

 plots. Numerous tables of the results were exhibited. ^ ^ 



" Turning," they add, "to the bearing of the results on the 

 main subject of inquiry, it appeared that when ammonia-salts 

 were used alone, year after year, on the same land, the composi- 

 tion of the ash, both of the grain and straw, showed an ap2^feciahle 

 decline in the amount of phosphoric acid, and that of the straw a 

 considerable reduction in the percentage of silica.^^ Further on in 

 the same paper, the farmer is told that the experimentalists " do 

 not recommend such exhaustive practice as that quoted from their 

 own experiments." Ten years previously (in 1851) the "inex- 

 haustible " theory was in a more vigorous stage of its existence. 

 Then the colossal reserves were only deemed liable to contingent 

 exhaustion, in the double event, first of the discovery (not yet 



