. 



1G8 SCIENTIFIC AGRICULTURE. 



Pe.it is usually found also in low boggy or marshy districts. 

 According to Dr. McCulloch, "by the long continued action of 

 water and other agents, the geine of peat is changed into bitu- 

 men and carbon, which constitute lignite and bituminous coal : 

 in a few instances the process of bitumenization has been found 

 considerably advanced in beds of peat." 



Peat is remarkable for its power of preserving animal mat- 

 ters from putrefaction. 



The following is an analysis of a specimen of peat from 

 Massachusetts. 



Soluble geine, - 26.00 



Insoluble do. - - 59.60 



Sulphate of Lime, - - 4.48 



Phosphate of do. - - - - 0.72 



Silicates, - 9.20 



100.00 



When the decay is far advanced, the peat is a dark colored 

 and sometimes solid mass; when less advanped in decomposi- 

 tion, it is light brown, spongy, and contains pieces of vegeta- 

 bles not yet disorganized, in this state it is used in some 

 countries as fuel. Peat is sometimes sour, from the presence 

 of phosphoric and acetic acids : it sometimes also contains am- 

 monia; it decomposes slowly in the open air. When mixed 

 with lime or potash and fermenting barn-yard manure, it 

 becomes a valuable fertilizing agent, and may be used on any 

 soil which requires the addition of vegetable matter. 



HUMUS. 



Humus is a brown or blackish colored substance, composed 

 of vegetable matter in a state of decay. " Humus [says Bous- 

 singault,] is the last stage in the putrefaction of vegetable 

 organic matter : its elements have acquired a stability which 

 enables them to resist all fermentation." It is of a spongy 

 texture, easily pulverized, and nearly insoluble in water: it 



