192 OF MANURE. 



But there are still simpler means of effecting this 

 purpose; — gypsum, chloride of calcium (bleaching 

 salts), sulphuric or muriatic acid, and super-phos- 

 phate of lime, are all substances of a very low price, 

 and completely neutralize the urine, converting its 

 ammonia into salts which possess no volatility. 



If a basin, filled with concentrated muriatic acid, 

 is placed in a common necessary, so that its surface 

 is in free communication with the vapors which rise 

 from below, it becomes filled after a few days with- 

 crystals of muriate of ammonia. The ammonia, the 

 presence of which the organs of smell amply testify, 

 combines with the muriatic acid and loses entirely 

 its volatility, and thick clouds or fumes of the salt 

 newly formed hang over the basin. In stables the 

 same may be seen. The ammonia that escapes in 

 this manner is not only entirely lost, as far as our 

 vegetation is concerned, but it works also a slow, 

 though not less certain destruction of the walls of 

 the building. For when in contact with the lime of 

 the mortar, it is converted into nitric acid, which 

 gradually dissolves the lime. The injury thus done 

 to a building by the formation of the soluble nitrates, 

 has received (in Germany) a special name, — salpe- 

 terfrass. 



The ammonia emitted from stables and necessaries 

 is always in combination with carbonic acid. Car- 

 bonate of ammonia and sulphate of lime (gypsum) 

 cannot be brought together at common temperatures, 

 without mutual decomposition. The ammonia enters 

 into combination with the sulphuric acid, and the 

 carbonic acid with the lime, forming compounds 

 which are not volatile, and consequently destitute of 

 all smell. Now, if we strew the floors of our stables, 

 from time to time, with common gypsum, they will 

 lose all their offensive smell, and none of the ammo- 

 nia which forms can be lost, but will be retained in 

 a condition serviceable as manure. 



With the exception of urea, uric acid contains 

 more nitrogen than any other substance generated 



