1284. Pigeons' dung comes next in order, as to fertilising power: 100 grains, digested in hot water for some hours, produced 23 grains of soluble matter; which afforded abundance of carbonate of ammonia by distillation, and left carbonaceous matter, saline matter principally common salt, and carbonate of lime, as a residuum. Pigeons' dung, when moist, readily ferments, and, after fermentation, contains less soluble matter than before; from 100 parts of fermented pigeons' dung, only eight parts of soluble matter were obtained, which gave proportionably less carbonate of ammonia in distillation than recent pigeons' dung. The soil in woods, where great flocks of wood-pigeons roost, is often highly impregnated with their dung, and, it cannot be doubted, would form a valuable manure. Such soil will often yield ammonia when distilled with lime. In the winter, likewise, it usually contains abundance of vegetable matter, the remains of decayed leaves; and the dung tends to bring the vegetable matter into a state of solution. Manuring with pigeons' dung was, and still is, in great esteem in Persia.