CHEMISTRY AND FARMING. 303 



Supposing you are desirous of raising a clover crop upon a 

 piece of land for several consecutive years. You begin. The 

 first year you obtain an abundant crop, the next it is sensibly 

 diminished, the next, perhaps, it is almost an utter failure. 

 You dress the land abundantly with animal manure ; tliat aids 

 somewhat, but still your crops rapidly decline, and you come to 

 the conclusion that clover is an amazingly exhausting crop. 

 You think it almost equals the tobacco plant in plundering the 

 soil. Clover is now abandoned, and, with but little confidence 

 in results, you sow rye upon the field. Harvest time has come, 

 and what a yield ! It exceeds all former precedent. You are 

 puzzled; you are perplexed. You cannot explain how such 

 worn-out land, which could not grow a hundred heads of clover, 

 should fill your rye-bins to overflowing. Chemistry would here 

 have taught a useful lesson. The first two or three crops of 

 clover exhausted the lime in your soil, and you did not supply 

 it, as you might have done with a few bushels of plaster or gyp- 

 sum, which is a sulphate of lime. The manure which you so 

 continuously applied contained too little of this substance to aid 

 materially. Your clover starved in its earliest infancy for want 

 of its proper kind of food. Rye requires but the least trace of 

 lime, and feeling the full influence of your dressings, produced 

 copiously. This is the explanation which an analysis of the soil, 

 and the clover and the rye, would have promptly afforded. A 

 few months since I was examining a piece of pasture land on a 

 neighboring farm, a portion of which was covered with a mag- 

 nificent crop of white clover, produced by a dressing of gypsum. 

 The patch was like an oasis in a desert. It blossomed there in 

 honeyed sweetness, while around the earth was parched and 

 sterile. An examination of that soil showed almost an entire 

 absence of lime and sulphur, and every blade of grass was in 

 the last stages of starvation for the want of them. There are but 

 few pastures in Essex which have been long cropped, which 

 gypseous dressings will not benefit. The lime the soil originally 

 contained at the surface has been carried off in the bones and 

 excrement of the animals feeding so long upon the grasses of 

 the same. Our soils, being formed in a great measure from the 

 prevailing quartose granite, abound in silica ; but lime is an 

 ingredient more sparsely disseminated through thein than is 

 beneficial for many important crops. Hence, we may regard 



