The Peruvian guano, moreover, con tains from 10 to 25 per cent. of phosphate of lime, the same substance as bone-earth, but elaborated by the birds into a pulpy consistence, which, while it continues in soluble in water, has been thereby ren dered more readily absorbable and diges tible (so to speak) by the roots of plants. There is therefore no doubt, that by the judicious application of these genuine gu anos, mixed with twice or thrice their weight of a marly or calcareous soil, to convert their phosphate of ammonia into phosphate of lime and carbonate of am monia, as also to dilute all their ammoni acal compounds—such crops will be pro duced, even on sterile lands, as the far mer has never raised upon the most im proved soil by the best ordinary manure. To the West India planter, guano will prove the greatest since it conden ses in a portable and inoffensive shape the means of restoring fertility to his ex hausted cane-fields, a benefit it has long conferred on the poorest districts of Peru.
Messrs. A. Gibbs, of London and Li verpool, have a monopoly of the sale of Peruvian guano. This, perhaps, is pot to be regretted, as what comes direct frbm them is genuine, and otherwise it is im possible to procure an unadulterated ar ticle, so great is the temptation and exten sive the use of the article. A sample lately imported into New-York by Messrs. A. 13. Allen, Water-st., N. Y., and ana lyzed by the editor, afforded by chemical examination in 100 parts, Water 7 83 Organic matter and salts of ammonia as urate oxalate and sulphate 6919 Phosphates of lime and magnesia and ammonia phosphate of magnesia 1160 Lime •60 Sulphuric acid 3.
Alkaline salts, chloride of sodium, and traces of poises '48 Sand 120 100•00 This guano was capable of yielding 12i per cent. of ammonia.
The following analysis of a good sample of Peruvian guano made by the late Mr. Fownes, England, affords a good idea of what is the constitution of a superior ar ticle in 100 parts : Azotized animal matter, including urate of ammonia and other ammo niacal salts, together, capable of af fording . from 8 to 16 per cent of ammonia by slow decomposition in the soil 50• Water 11• Phosphate of lime 25• of ammonia, oxalate of am monia, phosphate of magnesia, toge ther, yielding from 5 to 9 parts of ammonia 13• Silica l• 100• From tho foregoing analysis its valu able character is evident. This is sus
tained by the astonishing and generally profitable results which follow its appli cation, and has rendered it, though cent introduction, one of the most popular manures in this country and Europe. It has been known and appreciated by the Peruvians, from time immemorial ; and by its liberal use, combined with irrigation, they have for ages produced the most abundant crops of maize and wheat. It was not used agriculturally in Europe until 1840 ; in England at present 400,000 tons per year are used.
African. or Ichaboe and Patagonian guano have been brought into this coun try to a limited extent. They have been used with advantage, but are by no means equal to the Peruvian variety. Those guanos have been accumulated in damp climates, and have hence under gone decomposition, so that most, if not all, the urate of ammonia is broken up into oxalate of ammonia—a salt far loss valuable in agriculture : even this is dis sipated and washed away by the rains, so that the proportion of ammoniacal salts falls often in this variety below 20 per cent., leaving the phosphates in a corresponding excess, so that it more re sembles bones in composition.
Guano was first introduced into the States in 1825, when it was used in gar dens, and forgotten : after its use in England it was again re-imported. Its application here was but slow in in crease, yet it has advanced, and the de mand for this year will probably be 25,000 tons. Its value cannot be over-esti mated, as it is suitable for almost all crops and soils, but is perhaps best adapted for sandy loarns. From 2 to 5 cwt. is a proper dressing. It is better to compost it with five times its bulk of loam, vegetable mould, or with char coal or gypsum. Lime or ashes must ho avoided carefully, as the ammonia is thus driven off. It should be kept dry and under cover, as that which smells stron est is losing its ammonia. It is usually spread broadcast on meadows and grain, or placed with the seeds in the hill : it develops both leaf and ear wonderfully, and hence is as suitable for grain as for green crops ; it ought to be used only in autumn or in spring in the south. The sun's heat is too great for summer application, the loss of ammonia being very great.