A MODERN DISCOVERY. 399 



stances to the soil of which it has been exhausted in the process 

 of cropping, and to furnish them in such form, and so combined, 

 as that they may be best taken up by the plant, and presented to the 

 plant only so gradually as the habits of the plant may require. 

 This eminent chemist claims, to use his own words, &quot;to have 

 found means to give to every soluble ingredient of manure, by its 

 combination with others, any degree of solubility without alter 

 ing its effect on vegetation. I give, for instance, the alkalies in 

 such a state as not to be more soluble than gypsum, which, as is 

 well known, acts through many years, even as long as a particle 

 of it remains in the soil. The mixture of manures has been 

 adapted to the mean quantity of rain in this country, (England;) 

 the manure which is used in summer has a greater degree of solu 

 bility than that used in winter. Experience must lead to further 

 results, and in future the farmer will be able to calculate the 

 amount of produce of his fields, if temperature, want of rain, &c., 

 do not oppose the manure coming fairly into action. I must, 

 however, observe that the artificial manures in no way alter the 

 mechanical condition of the fields ; that they do not render a 

 heavy soil more accessible to air and moisture ; for such fields the 

 porous stable manure will always have its great value ; it can be 

 given together with the artificial manure.&quot; * 



With the highest respect for this eminent man, whose scien 

 tific labors have given a spur to agricultural inquiry and experi 

 ment unknown in any former time, one cannot but remark the 

 convenient reservation afforded by the qualification &quot;if tempera 

 ture, want of rain, &c., do not oppose the manures coming fairly 

 into action ; &quot; and the recommendation to apply the stable ma 

 nure together with the artificial manure, and the statement, in 

 another place, that certain manures &quot;act far more favorably on the 

 production of grain crops, especially if they are added to the 

 animal excrements, and are given to the fields at the same time,&quot; 

 present sagacious and certainly very safe advice. They slightly 

 remind one of a custom formerly prevalent in some Catholic 

 countries on the Continent, when, at the opening of the spring, 

 the priest was accustomed to go over the fields of his parishion 

 ers to give them his blessing ; but when he came to fields which 

 were exhausted and sterile, he was very careful to add, &quot; This 

 needs manure.&quot; The doctrine of the occasional and temporary 



* Liebig- on Artificial Manures. 



