178 MASSACHUSETTS HORTICULTURAL SOCIETY. 



hard, and becomes apparently barren. The trouble is, it has had 

 an enormous application of ammonia and phosphoric acid, but 

 nearly none of potash ; and the result is what always will ultimately 

 happen on any soil where one of the three requisite elements of 

 fertilizers is left out. Such soils are dying for tlie want of potash. 

 To lecuperate them, apply potash or manures rich in potasb, and 

 their fertility can be restored. Soils abounding in clay will bear 

 fish-manuring without showing injury longer than those of a 

 gravelly- character. 



Other Sources supplying Nitrogen. Guano. — At the head 

 of "fertilizers," as distinguished from barn manure, stands guano. 

 This ma}' be defined as rotten sea-bird dung, with rem;iins of birds 

 intermixed. It is found on thousands of islands; but in large 

 quantities on only a few. Being excrement of birds that feed on 

 fish, it would, therefore, be found to contain the same manure 

 elements as fish remains, but that rains dissolve and wash away 

 the ammonia, leaving beiiind onl}' phosphate. A few islands, 

 however, lying near the Peruvian coast, are rainless ; as what 

 would otherwise be the rain-bearing wind of that region loses all 

 its moisture in passing the high dry crest of the loft}- Andes. 

 These islands yield a guano that is rich in ammonia. 



There are several kinds of guano in. the market, known as 

 Rectified, Guaranteed, Standard, Lobos, Navassa, Caribbean, etc., 

 of which the first three named are varieties of the Peruvian (some- 

 times also called Chincha, or Guanape, according to the locality 

 where iound), all ricli in ammonia: Standard containing from 

 nine to ten per cent. ; Lobos from five to five and one-half, and 

 Guaranteed from six to seven. Each -is rich in phosphoric acid, 

 nearly all soluble ; and has from two to three per cent of potash. 

 The Navassa and Caribbean Sea guanos are rich in insoluble phos- 

 phoric acid, but are entirely wanting in nitrogen and potash. The 

 Standard is quoted to me, at the time of writing (Februar}', 1885), 

 at $63 per ton of 2,240 pounds, and the Lobos at $48. . The 

 analysis published by dealers gives to the former from nine to ten 

 per cent of ammonia, twelve per cent of phosphoric acid, and 

 three per cent of potash. The dealers assert there is no manipu- 

 lation of guano except by adding sulphate of ammonia. 



It is claimed that the nitrogea in the guano has a value over 

 that contained in manure into which enters fish blood or meat as 

 a supply of ammonia (hence called " organic nitrogen ") ; inas- 

 much as in the guano it is in a form ready to be taken up by plants. 



