234 BOARD OF AGRICULTURE. 



for the next twenty-five years, the yield should not be a bushel or 

 two more ; but we have not lived those other twenty-five years, 

 and we cannot tell positively. 



The worst soil we can point out has a certain natural capacity. 

 Take our rocky hill ranges in this State : if we should give a little 

 care to them, we could harvest every twenty-five or thirty years, 

 a certain crop of wood from them ; and if we should begin that 

 culture now, and carry it on for a hundred years, we should get 

 the same crop the last thirty years that we did the first thirty. If 

 we carried it on for a thousand years, the climate and circum- 

 stances generally, remaining as they are, we could depend upon 

 getting from them three uniform wood crops every century. So 

 in the poorest pasture, we have a certain natural productiveness, 

 which remains the same, so long as the state of the soil is un- 

 altered. The field may become a swamp, or its natural water- 

 supply may be dried up by local changes, but independently of 

 accidents like these, it will manifest a certain nearly uniform 

 natural strength from generation to generation. All production 

 of vegetable matter in the soil, of any kind, is the result of change 

 — the result of chemical and physical change. Natural strength 

 depends upon changes in the soil which act- in a nearly invariable 

 manner for long periods of time. The "Tooth of Time," is an 

 expression belonging indeed to figurative literature, but one also 

 fully justified by fact It is a tooth whose action never ceases 

 and whose Sharpness is never blunted. The grand rock-ridges 

 and peaks which make the mountains of the globe, although they 

 have held their crests aloft in flinty defiance through all the 

 periods of human history or tradition, are slowly wasting under 

 its incessant bite, and the explorer in the high Alps hears from 

 hour to hour the thunder-like noise with which the huge blocks of 

 granite, loosened from the mountain tops, crash downwards. At 

 the base of any high cliff you may see a (alus of sharp-angled 

 stones reaching half up the breast of rock, unless some rapid 

 stream of water or slow- pushing glacier is there to carry them 

 away. Our level fields are or have been covered with lumps of 

 rock, and our soil is full of them, but these are not sharp-edged as if 

 just struck off by a hammer-blow, but they are rounded in all their 

 outlines; the "Tooth of Time" has not ceased to eat away at 

 every angle and corner of these tempting morsels as the teeth of 

 children gnaw at sugar plums. Nor does the work stop here. 

 As they lie out on the pasture or buried in the plow-land, the 



