I. AGRICULTURE 'AND RURAL ECONOMY. 383 



probable, therefore, that, as well in the soil as in the at- 

 mosphere, nitrogen must first have been combined with other 

 elements before it can be efficient as a fertilizer, and that the 

 soil has no power of bringing the free nitrogen of the air 

 into such combination. 



NEW GUANO DEPOSITS OF PERU. 



It will be of interest to our agriculturists, as well as to 

 manufacturers of artificial fertilizers, to learn that the new 

 guano deposits of Peru are said to be very decidedly superior 

 in commercial value to those of the Chincha Islands. Pro- 

 fessor Raimondi, of Lima, has lately made a report to the 

 government, in which he makes the following remarks : 



" The guano of the province of Tarapaca is dry and pow- 

 dery ; some specimens not containing 15 per cent, of water, 

 among which thirty-three seemed about equal in that respect 

 to the Chincha guano. The guano of the south of Peru has, 

 in this, an advantage over that of Guanape, which is pasty, 

 and not so easily spread over the soil. The guano of Tara- 

 paca, from its dryness, makes the uric acid and other nitrog- 

 enous principles less apt to be decomposed. In guano more 

 abounding in humidity those elements become transformed 

 into carbonate of ammonia, which, being volatile, escapes dur- 

 ing transportation. This guano, although abounding in am- 

 monia, has little smell, and from this fact might be judged 

 of less value ; the want of a strong ammoniacal odor being 

 due, not to lack of ammonia, but from two different causes. 

 1. Being very dry, as before observed, the formation of car- 

 bonate of ammonia does not so readily take place. The pres- 

 ence of a strong ammoniacal smell indicates that the ammo- 

 nia is being given off, and this condition, instead of being 

 favorable, is prejudicial. 2. The ammonia in this guano is 

 combined in great part with phosphoric acid, under the form 

 of phosphate of ammonia, which is a fixed salt, and emits no 

 smell. The association of ammonia with phosphoric acid 

 gives a greater importance to this article, because those two 

 most valuable elements of all kinds of manure existing in a 

 soluble state are more easily taken up by plants, a circum- 

 stance which makes the guano of Tarapaca preferable and 

 superior to all others yet known. In these guanos, phosphor- 

 ic acid in a soluble condition prevails to the extent, in many 



