CALCAREOUS MANURES-APPENDIX. 251 



these means, I marled SO acres this year, 1821, (and that much too heavily,) 

 and had all the lessened corn-field on marled land. The product of the half 

 was equal to what the whole had brought before, and I was enabled there- 

 after to have every field marled over in advance of its next cultivation. In 

 1822, the land marled was 93 acres, 100 in 1823, and SO in 1824, which 

 served to cover nearly all of the then cleared land requiring marling. The 

 next three years' marling amounted respectively to 50 acres, 24 acres, and 

 27 acres, being principally upon land subsequently cleared and brought into 

 cultivation. Since then, there has been no mai-ling on the farm, except on 

 wood-land, not yet cleared, and on small spots formerly omitted, and of 

 which no account was taken. With the exception of such spots, (and some 

 such still remain, because of their inconvenient position,) all the land which 

 was not naturally calcareous, or too wet or too steep for carting on, had 

 been marled by 1827 ; and none has required any additional dose, though 

 some of the thinnest covered places had been re-marled long before that 

 time, so as to bring them to a proper constitution. 



In 1824, I first observed, (and had never before suspected such effect,) 

 the injury caused by having marled acid soil too heavily. To show my first 

 impressions, I will copy the words of my farm journal, written on the very 

 day on which the discovery was fully made. 



"June 13th, 1824. Observed a new and alarming disease in a large pro- 

 portion of my corn ; and, what makes the matter much worse, the evil is 

 certainly caused by marling. The disease seems to have conunenced when 

 the corn was from 6 to 10 inches high, and to have stopped its growth. Its 

 general color is a pale sickly green, and the leaves appear so thhi as to be 

 almost transparent : next they become streaked with rusty red, and then 

 begin to die at the upper ends. Several pulled up, showed no defect, or 

 injury from insects, among the roots. All Me land marled from pits Nos. 7 

 and 9 (both yellow) from 1820 to 1822, is so much diseased as to promise 

 not more than half a crop. The corn is twice as large as on the spaces left 

 for experiment without marl, yet looks much worse ; though three weeks 

 ago its superiority in color and vigor was even more than in size. With 

 but few exceptions, the land newly marled from the same pits, and the old 

 marling from Nos. 1 and 8, (both blue,) as well as that not marled, are free 

 from this disease. The parts most affected are those which were driest and 

 poorest, and of course were least covered with vegetable matter. Yet 

 though the corn on this old marling is generally so bad, it is yet evident that 

 the land is more benefited by the manure than at first : flourishing stalks of 

 corn, 18 to 24 inches high, are seen frequently within a few feet of those 

 most hurt by this disease." 



Subsequently, when the whole extent of injury could be seen, the follow- 

 ing remarks were written in the journal, at the date below. 



"October 15th. The damage caused by marl to this crop I suppose to be 

 about one third of what the land would otherwise have made, judging from 

 the present and former measurements of the same land, where experiments 

 were made. 



"Nearly all the heavy marling in Finnies, (at 800 bushels,) about 20 

 acres,* suffered by it ; the poorest and lightest most injured, here and in 

 Court-House field. The few rich spots escaped, as did most of the piece 

 plastered (on the heavy marling) in 1820. The marks of this experiment 

 were destroyed, and the superiority was not so regular as to enable me to 

 trace the outlines of the gypseous earth— but an acre of corn might be 

 taken which certainly was plastered, better than any other acre in the old 



♦ See Exp. 10, p. 83, Essay on Cal. Man. 



