[Span.] The dung of a sea-fowl, used as a manure, because it contains an abundance of the silicious skeletons of animalcules, and is rich in phosphates and ammonia. Guano was first brought to Liverpool in 1839, from the Chincha Islands on the coast of Peru, but is now exhausted there. It is now obtained from the Macabi and the Huanape Islands. Countless numbers of sea-birds have lived on these islands for thousands of years, and as rain seldom falls their excrement has accumulated to a depth of 200 feet. Guano has a pungent smell, due to the ammonia it contains. By adding to the guano some sawdust wetted with sulphuric acid, the ammonia is fixed, so that its loss is prevented. Guano is an excellent manure for wheat, potatoes, and green crops on strong clay soils. In the great bat-caves of San Antonio, Texas, a shaft has been sunk some hundreds of feet back from the mouth, by means of which it is possible to dig out the guano of the bats without disturbing the enormous number of sleeping bats that doze there during the day. The guano of these bats is the finest exported, because never exposed to rains, which wash out much of the virtue of Peruvian guano.