MR. NICHOLS' ADDRESS. 13 



kind, how can you be sure to meet it without applying all varieties 

 of manure? In doing this you would certainly be acting on a level 

 ■with the famous herb doctor, who, ignorant of the nature of disease, 

 an(? ignorant of the medicinal virtues of the various roots and herbs 

 he prescribed, came to the conclusion that to hit his cases positively, 

 his only course Avas to steep a mass of all kinds together, and pour 

 the decoction down the throats of his patients. 



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 an almost an utter failure. You dress the land 

 abundantly with animal manure ; that 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. Har- 

 vest time has come, and what a yield. It exceeds all former pre- 

 cedent. 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 mi^ht have done, with a few bushels of plaster or gypsum, 

 ■which is a sulphate of lime. The manure you so continuously ap- 

 plied contained too little of this substance to aid materially. Your 

 clover starved in its earhest infancy, for want of its proper kind of 

 food. Rye requires but the least trace of lime, and feehng the full- 

 influence of your dressings, produced copiously. This is the expla- 

 nation which an analysis of the soil, and the clover, and the rye, 

 ■would have promptly afibrded. A few months since I was exam- 

 ining a piece of pasture land, on a neighboring farm, a portion of 

 which was covered with a magnificent crop of white clover, pro- 

 duced by a dressing of gypsum. The patch was like an oasis in a 

 desert. It blossomed there in honied sweetness, ■while around the 

 earth was parched and sterile. An examination of that soil show- 

 ed 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 



