AGRICULTURAL TEXT-BOOK. 



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will supply their portion to the soil. The bones and flesh of fish 

 very nearly resemble those of quadrupeds in their phosphates and 

 nitrogen; fiyh, however, generally affording more free oil. 

 They should always be composted with muck, peat, &c. 



689. Shell fish are rarely found sufficiently numerous to bo 

 used as a manure, except in a mineral state. In New England, 

 muscles and oyster shells are collected. In Alabama there are 

 vast deposits of this kind ; and according to Dr. Houghton (M. 

 S.,) much of the marl of Michigan is formed of recent shells. 

 They chiefly consist of lime, a little phosphoric acid, animal 

 matter, and in salt water, iodine, and soda. 



690. BARN YARD MANURES are composed of the dung and 

 urine of animals, with hay, straw, &c., more or less decayed, and 

 they necessarily differ much according to (a,) the species ; (b,) 

 the age of the animal ; (c,) the food it eats ; (d,) the mode in 

 which the dung is preserved, whether exposed to rain, sun, &c. ; 

 (e,) the quantity of urine contained; (f,) the decomposition 

 which has taken place; (g,) whether alkalies or lime are 

 in connection with it during decay, and how long. 



691. Table exhibiting the amount in pounds of carbon, &c., 

 in the food and dung of two cows during fourteen days. 

 (Thompson.) 



(See also, Licbig s Animal Chemistry. Note 4.) 



