304 IMPROVEMENT OF THE SOIL 



soil and ploughed in, or formed into compost with fish, or the 

 refuse of the cattle yard. In either case it is an active ma- 

 nure ; but its effects are not lasting, probably owing to the 

 ease with which it is decomposed and either dissipated or ab- 

 sorbed by the roots of plants. It may be used for litter, to 

 absorb the liquid and gaseous products of the stables, with 

 the best results. Its value has been fully tested by many 

 farmers who reside in the vicinity of the sea. 



II. Peat, sivamp muck and pond mud. These sub- 

 stances are very abundant in the eastern part of Massachu- 

 setts. Almost every farm throughout the country contains 

 either peat, muck or mud in sufficient quantity for farming 

 purposes. 



1. Peat is derived from the decayed roots of sphagnous 

 mosses, ferns, stalks of swamp-plants and decaying leaves ; 

 the peat moss constitutes the principal mass. There is also 

 a small quantity of mineral matter, such as silex, clay, lime 

 and magnesia, either mixed with it or combined with vege- 

 table acids. Some varieties contain sulphate of lime (gyp- 

 sum), oxide of iron and of manganese. The value of peat as 

 a manure may be seen from its composition. The mean of 

 20 analyses of the peats of Rhode Island, by Dr. Jackson, 

 gave the following results. 



Four specimens contained a small quantity of potash, and 

 one specimen contained 1.2 per cent, of phosphate of magnesia. 

 It will be seen that peat contains a large quantity of vegetable 

 matter and of salts. 



2. Sivamp muck consists of the pairings of the peat, and is 

 less compact. It is found in every meadow, and includes the 

 hassocks. It also includes the variety of peat which has be- 

 come partially decomposed, and the mud of salt marshes. 



3. Pond mud is found at the bottom of ponds, when dry, 



