1851.] of (he Soil to its Fertility. 85 



constituents of the soil, which lie buried under the shallow crust of 

 cultivated earth. An inquiry into the causes of the fertility of the 

 soil may appropriately be divided into a consideration of the chem- 

 ical and the physical nature of the soil. Both roads in which the 

 question is to be pursued run for a time in the same direction, join- 

 ing hands at every step ; there is a point, however, where they may 

 be said to diverge, the one leading into the wide field of agricultural 

 profession ; the other into the darker labyrinths of chemical science, 

 in which, high attainments, that but few possess, are required, to 

 conduct investigation in so correct and minute a manner, as to ren- 

 der them beneficial and of any real value. Whether it is expedient 

 that the aoriculturist should rise to these higher rea-ions of theoret- 



o (jo 



ical knowledge, I would refer to the wiser judgment of the philan- 

 thropist ; he will, however, be highly profited by a clear and thor- 

 ough understanding of the physical nature of the soil he is called 

 to cultivate, and he will thereby learn the most profitable mode in 

 which to employ his physical powers. 



Carbonic acid, ammonia and water, obtained from the decomposi- 

 tion of animal matter, are held in immense stores, in the atmos- 

 phere, for the nourishment of the vegetable kingdom. All plants 

 take up freely such quantities of these substances as are necessary 

 to their subsistence and growth. The difterence in their success in 

 different soils and localities can not, therefore, be dependent on these 

 organic nourishments, but it must be sought in the various mineral 

 constituents of the soil. That mineral substances, dissolved in wa- 

 ter, pass into the vegetable body, is clearly demonstrated by the fact, 

 that various salts and alkalies are found in the ashes of the plant. 

 This theory was first established by the ingenious chemist, Justus 

 LiEBiG, whose researches and discoveries have greatly revolutionized 

 former principles of agricultural chemistry, securing a world-wide 

 fame to their originator. We have the prophesy from another 

 shrewd philosopher, that, in a future day, the aphorism of science 

 will thus run : " The whole wealth and the whole manifoldness of 

 terrestrial vegetation — its whole variety, as well when we compare 

 zones of longitude and latitude, as wild nature with cultivated lands, 

 are exclusively dependent on the variety of inorganic constituents 

 which the plant takes up from the soil." Various objections present 

 themselves to this theory, and much, undoubtedly, will be said 

 for and against its value, before it is fully adopted or rejected by all 

 parties, and it is to be hoped that some one, skilled in the mysteries 



