12 



of land to absorb water," Mr. Humphrey says, " depends in a 

 great measure upon the division of its parts. The more divided 

 these are, the greater its absorbent power. When this power is 

 great, the plant is supplied with moisture in dry seasons. The 

 effect of evaporation in the day is counteracted by the absorption 

 of aqueous vapors from the atmosphere, by the interior parts of 

 the soil during the day and by the exterior and__interior during 

 the night." I have thought of this remark when I have seen a 

 man plant a tree, by digging the soil just deep enough to cover 

 the roots, and then setting it on hard pan or a'^gravel bed, wonder 

 why it did not Hve, or if it did languishingly live,^as we say in 

 the law, why it did not grow ; as if a tree, as well as a man had 

 not an inherent right to die of thirst or starvation. Put the same 

 tree upon good rich loam, thoroughly stirred and decomposed to 

 the depth of two and a half or three feet, and if underdrained all 

 the better ; keep the ground open and loose about it, give it a 

 little mulching, in a dry season, and its growth will be such that 

 Jonah's a;ourd will no longer seem miraculous. 



The object of all mechanical operations on the soil is to expose 

 the greatest possible surface to the influence of the atmosphere. 

 The plough, the harrow, the spade, the hoe, accelerate the decom- 

 position of the soil. The rapidity of the decomposition of a sohd 

 body increases with the extension of its surface. " The more 

 points of contact we offer," says Liebig, " to the external chemi- 

 cal agent, the more rapid will be its action." An extension 

 of surface almost infinite, any one can see, is gained by the sub- 

 division of its particles. 



But into the details of this beautiful science of agricultural 

 chemistry I may not venture to go further. I fear I should soon 

 get beyond my depth. These imperfect illustrations may suffice 

 to show that we must have its aid and guidance, if we would 

 thoroughly subdue the earth. I should be happy, if I thought 

 they would attract you to the study of the science itself. Its 

 principles should be better understood. They underlie our art. 

 They are at once the seed and the fruit of its progress and 

 growth. 



This doctrine of the necessity of thoroughly subduing the earth 

 may throw some light upon the vexed question of small or large 



