404 PHILOSOPHICAL TRANSACTIONS. [aNNO J 708. 



The second way is by liming. This is much better than the former, because 

 it does not so much impoverish the ground, it lasts longer, and produces better 

 grain, and does not destroy the grass if due care be taken not to over ploug^h 

 it. But this is very dear, and lime-stone is not every where to be had, and in 

 many places fuel is wanting. Dung is the common manure in all places, and 

 therefore I shall say nothing of it. 



Marl is not used in the north parts of Ireland; but about the sea side the 

 great manure is shells ; towards the eastern part of the bay of Londonderry, 

 commonly called Loughfoyle, lie several eminences, that hardly appear at low 

 water; these consist of shells of sea-fish of all sorts, more particularly of peri- 

 winkles, cockles, limpets, &c. The countrymen come with boats at low water, 

 and carry loads of these shells away ; they leave them in heaps on the shore, 

 and there let them lie till they drain and dry, to render them lighter for car- 

 riage ; they then carry them by boats as far as the rivers will permit, and then 

 in sacks on horses, perhaps 6 or 7 miles into the country. They allow some- 

 times 40, but mostly 80 barrels to an acre. These shells agree with boggy, 

 heathy, clayey, wet, or stiff' land, but not with sandy. They seem to give the 

 land a sort of fermentation, as yest does to bread, opening and loosening the 

 clods, and by that means making way for the roots to penetrate, and for the 

 moisture to enter into the fibres of the roots. The manure continues so long, 

 that none can determine the time of its duration. The reason of which seems 

 to be, that the shells dissolve every year a little, till they be all spent, which 

 requires a considerable time ; whereas lime, &c. operates all in a manner at once; 

 but it is to be observed, that in 6 or 7 years the ground grows so mellow, that 

 the corn on it grows rank, and runs out in Straw to such a length, that it can- 

 not support itself, and then the land must be suffered to lie a year or two, that 

 the fermentation may abate a little, and the clods harden, and then it will bear 

 as long again, and continues to do so, with the like intermissions, for 20 or 30 

 years. In the years in which the land is not ploughed, it bears a fine grass, 

 mixed with daisies in abundance, and it is pleasant to see a steep high moun- 

 tain, that a few years before was all black with heath, on a sudden look white 

 with daisies and flowers. It fines the grass, but makes it short, though thick. 

 Observing that this manure produced flowers in the field, I made my gardener 

 use these shells in my flower garden, and never saw better carnations, or flowers 

 fairer or larger than in that cold climate. Besides, it contributes to destroy 

 weeds, at least it does not produce them so much as dung; it likewise produces 

 very good potatoes, at about a foot distance from each other. And this is one 

 method of reducing boggy barren land ; they lay a little dung or straw on the 

 land, and sprinkle it with shells ; sometimes they cut the potatoes if large, that 



