344 MATERIAL RESOURCES OF LIFE. 



j)OSse8sions. To take note of these ammoniacal materials, we have again to 

 begin at Peru. Standing on the shores which fi-ont the nitre-beds, and 

 looking west ujion the Pacific, there are seen, we are told, the low patches 

 of the Cincha Islands — islands which shine with the whiteness of a powdery 

 covering, a loose deposit of considerable depth. A cargo of this substance 

 was first taken to London in 1840, stored and advertised for sale, and after a 

 while thrown into the Thames. A second cargo was tried as a fertilizer by 

 an English farmer, and found to give such marvelous results that the ship- 

 ping company made good haste to contract with the Peruvian government 

 for the entire dejiosit. This article, well known as guano, has held a settled 

 value ever since its introduction, and, had it come into the hands of the al- 

 chemists, it would, very likely, have been presented as an elixir of vegetable 

 life. Now, its worth is graded b}^ analysis, and is indicated chiefly by the 

 proportion of ammonia it contains. 



The absence of rain will account, perhaps correctly, for the unusual 

 retention of the soluble material characteristic of the guano of Peru ; but the 

 formation of the nitre-beds of that region is a problem in geological chemis- 

 try more difiicult to determine. There are evidences of volcanic overflow 

 and marine deposition, and the alkali in the compound may have originated 

 in either of these or other sources, but neither the volcano nor the sea could 

 furnish the nitrogen of the compound. If not from organic accumulations, 

 we seem to be referred to the air as the source of nitrogen, and left to con- 

 jecture the conditions and forces which could bring elemental nitrogen into 

 union m so great a quantity. Without pursuing these inquiries, it may be 

 l^ermitted to cite a fact which seems entitled to consideration in the case, 

 namely, the conditions for an unusual overflow of atmospheric ammonia in 

 this region. It is fed by perj)etual trade-winds — winds coming from the 

 south-east across a wide continent of soil that is rich to rankness, and 

 warmed under a vertical sun. Coming from the Atlantic and saturated with 

 water, these winds gather the exhalations of a continent, and then, shedding 

 their water on the Andes, leave their ammonia (it may be supposed) to find 

 its way by some means to the valleys of the western slope. 



Again, these same mountain-valleys of Peru may claim to have given the 

 world still another token of unexampled sources of nourishment, in the 

 ■growth of the cinchona-tree, bearing the richest stock of nitrogenous bases 

 in the vegetable world. It seems, indeed, more than a coincidence that this 

 narrow, rainless, wind-nurtured slope of land should send to all the earth three 

 such eminent resources as Peruvian nitre, Peruvian guano, and Peruvian bark. 



Another of the materials adequate for no more than the needs of life is 

 phosphorus. This element so far difi'ers from nitrogen that it is not found 

 uncombined in Nature, and if separated by art it immediately enters into 

 combination on exposure to the air. It occurs chiefly in phosj)hate of lime, 

 taken from the mineral kingdom by plants and also by animals. The hard 

 part of bone is about nine-tenths phosphate, and phosphorus is an element 

 of molecules organized into muscle and nerve. 



