96 SOURCE AND ASSIMILATION OF NITROGEN. 



sand and clay, in order to procure the richest crop 

 of maize. The soil itself does not contain the 

 smallest particle of organic matter, and the manure 

 employed is formed only of urate, phosphate, oxa- 

 late^ and carbonate of ammonia^ together with a few 

 earthy salts.*" 



Ammonia, therefore, must have yielded the nitrogen 

 to these plants. Gluten is obtained not only from 

 corn, but also from grapes and other plants ; but 

 that extracted from the grapes is called vegetable 

 albumen, although it is identical in composition and 

 properties with the ordinary gluten. 



It is ammonia which yields nitrogen to the vege- 

 table albumen, the principal constituent of plants ; 

 and it must be ammonia which forms the red and blue 



numerable sea fowl that remain on them during the breeding season. 

 (See the Chapter on Manures.) 



According to Fourcroy and Vauquelin it contains a fourth part of 

 its weight of uric acid, with ammonia and potash. 



The London and Edinburgh Philosophical Magazine, for July, 1841, 

 contains a new analysis of the guano, made by M. Voelckel in the 

 laboratory of Professor Wohler. and confirms what Klaproth found, 

 viz., that it contains, besides unchanged uric acid, a considerable quan- 

 tity of two of its usual products of decomposition, viz. oxalic acid and 

 ammonia. 100 parts of moist guano, contain, 



{Voelckel), {Klaproth.) 



Urate of ammonia, . . . 9.0 16.0 



Oxalate of do 10.6 



Do. of lime, .... 7.0 12.75 



Phosphate of ammonia, . . . 6.0 

 Phosphate of ammonia and magnesia, 2.6 

 Sulphate of potash, .... 5.5 



Do. of soda, .... 3.8 common salt 0.05 

 Chloride of ammonium, . • . 4.2 

 Phosphate of lime, . . . 14.3 10.00 



Clay and sand, .... 4.7 32.00 



Undetermined organic substances,"^ 

 of which about 12 per cent, is sol- ( 32.3 28.75 



uble in water. A small quantity j 



of a soluble salt of iron. Water, J 



lOO.O 99.55 



Mr. J. H. Blake of Boston, who has recently visited Peru, informs 

 me, that near Pabellon de Pica there is a high hill, the base of which, 

 consisting chiefly of guano, is washed by the sea. From this bed, 

 which is nearly a mile in length, and from 800 to 900 feet high, guano 

 might be obtained at a cost, which would probably not exceed a cent 

 and a half per pound, delivered in the United States. (See also Ap- 

 pendix.) 

 * Boussingault. Ann. de Ch. et de Phys. Ixv. p. 319. 



