AGRICULTURAL TEXT-BOOK. 321 



quantity than in any other substance, that its beneficial effects 

 are chiefly due. 



Urea is a white salt-like substance, very soluble in water, consisting 

 of 



~ , Per cent. 



Carbon, ----. 200 



Hydrogen, - . . _ - 6 6 



Nitrogen, - - . . 46 &quot; 7 



Oxygen, .... 2 6.7 



Besides which, when the urine begins to ferment, this substance 

 changes entirely into carbonate of ammonia. As this rapidly escapes 

 into the air, the urine must be kept in covered vessels, and plaster, peat, 

 sulphuric acid, &amp;lt;fcc., may be mixed with it ; but burnt lime must not be 

 brought into contact with it. 



There are various modes of preserving the liquid manures of the barn 

 yard, such as tanks, sawdust, &amp;lt;fcc.; but probably, in all respects, the best 

 is the simple plan invented by Mr. Mechi, of England. This consists 

 of a shallow, water-tight cellar under the stable, with a floor made of 

 scantlings laid an inch and a half apart from each other, so that the dung 

 ado urine fall below, and are preserved till carried to the field. It is of the 

 utmost importance to the farmer to preserve this liquid ; and if one 

 must be lost, it ought to be the solid. 



699. GOOD BARN YARD MANURE, then, is a mixture of 

 dung, urine, and straw, kept from the rain and sun, decomposed 

 to a certain extent ; and its value, per ton, must depend equally 

 on the various proportions of these matters which it contains * 

 the food of the animals ; and the state of the decomposition, 

 &c. 



Analysis of barn yard manure, just previous to being ap 

 plied, at New Castle-upon-Tyne, England. (Richardson :) 



nr L Fresh. 



Water, . - . 6496 



Organic matter, - - . _ 2471 



Inorganic salts, ..... 1032 



f, , Dried at 212. 



Carbon, . 3? 4Q 



jiydrogen, - - . . 5 27 



Oxygen, - .... 25 52 



Nitrogen, j 76 



Ash, - ... 



21 



