On Manures. 209 



is rendered perniciously rich, while other parts of the pas- 

 ture derive but little benefit, except while they are eating 

 over it by day. 



2. Dung of Birds. This head refers to the dung of pi- 

 geons, domestic fowls, and sea-birds. 



Pigeons' dung certainly possesses much fertilizing power. 

 It readily ferments when moist; but is generally applied in 

 as fresh a state as possible, in gardens to onions, and in 

 fields, to crops of wheat or barley ; in which case, if mixed 

 with peat, twenty bushels per acre are sufficient. The 

 dung of pigeons is peculiarly excellent for carrots, as it pre- 

 vents the attacks of vermin. The dung of domestic fowls, 

 ought to be carefully collected in the poultry house or yard, 

 for it resembles pigeons' dung in its effects. But the most 

 valuable article of this sort is, the dung of sea-birds, which 

 live upon fish. This substance is produced in such quantities 

 upon some small islands in the South Sea, that fifty vessels are 

 annually employed, to bring it for the purpose of fertilizing 

 the sterile plains of Peru. It is there called quano. If the 

 rains of our climate, are found to injure this manure on the 

 rocks and small isles on our coast, yet it may be obtained in 

 great perfection in caverns or clefts, resorted to by cormo- 

 rants, auks and guillemots, and other water fowl ; and in the 

 West Indies, it may be collected on rocky islands, equal to 

 that used in Peru( 186 ). 



3. Town Dung. This is an important article, yielding, 

 in many cases, a considerable revenue to the towns, besides 

 fertilizing the neighbourhood ( l87 ). In large cities, the 

 quantity to be obtained is enormous, though it is to be la- 

 mented, that too much of it is thrown away and neglected. 

 In London, it is estimated, that the annual produce may 

 amount to 500,000 cart loads, being only a part of the ma- 

 nure collected, by sweeping 3000 acres of pavement in streets 

 and market places, and the dung produced by 30,000 horses, 

 8000 cows, and now, including the environs, nearly a million 

 and a half of inhabitants ( l88 ). The sweepings of streets af- 

 ford a species of manure, the effects of which are immediate, 

 but not very durable. The dung produced by the cows and 

 horses maintained in towns, if attention be paid to the pre- 

 paration, is particularly valuable, as the animals by which 

 it is produced, are generally maintained on food of the richest 

 quality. That of horse* being apt to become too dry, ought 

 to be regularly removed, and mixed with other substances. 



4. Night Soil. This is the richest of all manures, and if 

 dry, the cheapest ( l89 ). It is not only more quick in its ope- 



