70 CALCAREOUS MANURES-PRACTICE. 



benefit of these details. But, however disagreeable it may be to give to 

 them the necessary attention, I will presume to say that these experiments 

 deserve it. They will present practical proofs of what otherwise would be 

 but uncertain theory — and give to this essay its principal claim to be con- 

 sidered truly instructive and useful. 



When these operations were commenced, I knew of no other experi- 

 ments having been made with fossil shells, except two, which had been 

 tried long before, and were considered as proving the manure to be too 

 worthless to be resorted to again. 



The earliest of these old experiments was made at Spring Garden, in 

 Surry, about 1775, by Mr. Wm. Short, proprietor of that estate. The extent 

 marled was eight or ten acres, on poor sandy land. Nothing is now known 

 of the effects for the first twenty-five or thirty years, except that they were 

 too inconsiderable to induce a repetition of the experiment. The system 

 of cultivation was doubtless as exhausting as usual at that time. Since 

 1812, the farm has been under mild and improving management generally. 

 No care has been taken to observe the progress either of improvement or 

 exhaustion on the marled piece; but there is no doubt that the product 

 has continued for the last fifteen years better than that of the adjacent land. 

 Mr. Francis Ruffin, the present owner of the farm, believed that the pro- 

 duct was not much increased in favorable seasons ; but when the other 

 land suflTered, either from too much wet, or dry weather, the crop on the 

 marled land was comparatively but slightly injured. The loose reports 

 that have been obtained respecting this experiment are at least conclusive 

 in showing the long duration of the efiects produced. 



The other old experiment referred to was made at Aberdeen, Prince 

 George county, in 1803, by Mr. Thomas Cocke. Three small spots (nei- 

 ther exceeding thirty yards square,) of poor land, kept before and since 

 generally under exhausting culture, v^^ere covered with this manure. He 

 found a very inconsiderable early improvement, which he thought altoge- 

 ther an inadequate reward for the labor of applying the marl. The ex- 

 periment, being deemed of no value, was but little noticed until after the 

 commencement of my use of the same manure. On examination, the im- 

 provement appeared to have increased greatly on two of the pieces, but 

 the third was evidently the worse for the application. For a number of 

 years after making this experiment, Mr. Cocke considered it as giving full 

 proof of the worthlessness of the manure. But more correct views of its 

 mode of operation, induced by my experiments and reasoning, induced 

 him to recommence its use ; and no one has met with more success, or 

 produced more valuable early improvement. 



Inexperience, and the total want of any practical guide, caused my ap- 

 plications, for the first kw years, to be frequently injudicious, particularly 

 as to the quantities laid on. For this reason, tliese experiments will show 

 what was actually done, and the effects thence derived, and not what bet- 

 ter information would have directed as the most profitable course. 



The measurements of corn that will be reported were all made at the 

 time and place of gathering. The measure used for all except very small 

 quantities was a barrel, holding five bushels when filled level, and which 

 being filled twice with ears of corn, well shaken to settle them, and heaped, 

 was estimated to make five bushels of grain ; and the products will be re- 

 ported in grain, according to this estimate. This mode of measurement 

 will best serve for comparing results ; but in most cases it is far from giv- 

 ing correctly the actual quantity of dry and sound grain, for tlie following 

 reasons. The «ommon large soft-grnined white corn was the kind culti- 

 vated, which was always cut down for sowing wheat before the best 



