ARTIFICIAL MANURE. 179 



257. Under the general name of peat, are compri- 

 sed several varieties, which may be distinguished as, 

 1st. Peat, the compact substance generally known 

 and used for fuel, under this name. 2d. Turf, or 

 swamp muck, by which is to be understood, the 

 paring which is removed before peat is dug. It is 

 a less compact variety of peat. It is common in all 

 meadows and swamps, and includes the hassocks. 

 Both these varieties are included in the above, from 

 No. 1 to No. 10. It includes also, the mud of salt- 

 marshes. 3d. Pond mud, the slushy material, found 

 at the bottom of ponds when dry, or in low grounds, 

 the wash of higher lands. This seldom contains 

 more than 20 per cent, of geine. Nos. 1 1 and 12, 

 are of this description. 



253. These varieties comprise probably a fair 

 sample of all the peat and swamp muck and pond 

 mud, which occur in the various parts of the coun- 

 try. The results stated, (256) are those of the sev- 

 eral varieties, when dried, at a temperature of 300° F. 

 The composition of peat ashes has been alluded to 

 (163). They contain, in fact, all the inorganic prin- 

 ciples of plants, which are insoluble, with occasional 

 traces of the soluble alkaline sulphates, and of free 

 alkali. 



259. It is well known that all peat shrinks by dry- 



