BY PEAT MUCK AND POND MUD. 305 



and in low grounds. It consists of from 15 to 20 per cent, 

 of vegetable matter, which has been washed down from the 

 high lands and mixed with earthy materials. Dr. Dana has 

 given the composition of 10 specimens of Massachusetts peat 

 and swamp muck, dried at a temperature of 300° F. The 

 average quantity of ingredients is 85 per cent, of vegetable 

 matter ; of which 29.46 is soluble and 55.03 is insoluble ; 

 15.9 per cent, are salts and silicates. The composition of 

 pond mud is very different, only 5 to 8 of insoluble and from 

 6 to 9 per cent, of soluble vegetable matter or geine. The salts 

 of lime, however, are abundant, being about 2 per cent. It 

 should be remarked that the proportion of the soluble to the 

 insoluble portion is much greater in the mud than in the peat^ 

 and hence the effects of this substance will be more immedi- 

 ate, but not so lasting as peat and muck. 



When peat is first dry, it contains from 78 to 98 per cent, 

 of water. In drying, it shrinks tv/o-thirds or three-fourths of 

 its bulk. When green, it contains, of 



Water 85. I Silicates .5 



Salts of lime .5 | Humus 14.0 



looo 



If, now, we estimate the value of fresh dry peat as compared 

 with cow dung, we shall find that the two substances are con- 

 stituted almost exactly alike. The salts and the geine or hu- 

 mus, in every cord of peat, are equal to those produced by the 

 cow in three months. But there is one important difference. 

 The cow dung is capable of producing a large quantity of 

 ammonia, but the peat only contains slight traces of it. Still 

 there is found crenic and apocrenic acids, which may serve 

 the purpose of the ammonia, by yielding their nitrogen in the 

 processes of vegetation. 



The action of the ammonia, as we have remarked, is to in- 

 duce decay and consequent conversion of the insoluble geine 

 or humin into humic, crenic and apocrenic acids, or into solu- 

 ble geine. If, now, there is any process of adding to the 

 26 



