11 



When Liebig published his immortal work, " Chem- 

 istry applied to Agriculture and Physiology," he 

 taught the true value of Nitrogen in manure. But 

 soon after this, by reasoning upon a subieet, which 

 ran only be properly examined, by observation and 

 experiment, he jumped to a false conclusion. That 

 " allies represent the whole nourishment which vege- 

 tnhies receive from the soil/' 



Hence in using manures he says: ''Would not 

 their effect be precisely the same in promoting the 

 fertility of cultivated plants, if we had evaporated 

 the urine, and dried and burned the solid excre- 

 ment ?" 



This was his sincere belief. And year after year, 

 in every subsequent work, he would not bend a line 

 from his tangent, but struggled hard, by most ingeni- 

 ous argument, to carry the whole Agriculture of the 

 v/orld with him. 



Lawes and Gilbert subjected his theory to a most 

 rigid investigation. The ashes of 14 tons ol barnyard 

 manure were applied for 30 years in succession, on 

 the same acre, and produced each year, only two 

 bushels of wheat more than the continuously unma- 

 n u red acre. The artificial mineral manures were 

 also used in the same way, on another plot, and with 

 the same result. 



Besides all this, able chemists have demonstrated, 

 by growing plants in distilled water, that to produce 

 a good crop there must be nitrogen in the soil or in 

 the water. 



They have dissolved the ashes of plants in pure 

 water, and then, by adding a few grains of nitrogen 

 in the [form of a nitrate, have produced a luxuriant 



