MANURES, THEIR KINDS AND USES. 41 



dung, in respect to the quantity of ammonia being rated 

 as four to one. 



MUCK. 



When successive generations of plants have grown 

 and, with the leaves from surrounding forest trees, have 

 decayed on the same low, swampy soil, the vegetable mat- 

 ter increases so rapidly that, with the exception of that 

 supplied by the decaying mass, very little mineral mat- 

 ter is mixed with it. The mud from the bottom of a 

 pond, in or around which no plants grow, consists merely 

 of the washings from the higher ground, and deposits 

 from the water, and must be of inferior quality. It is 

 evident that muck must be very variable in quality, ac- 

 cording to its origin. The best, besides imparting valua- 

 ble humus to the soil, contains four per cent., or even 

 more, of nitrogen. In some instances, on the sea coast, 

 a rich deposit may be subject to overflow at spring tides, 

 which, receding, leave marine animals that will fur- 

 ther enrich it. An application to plants of such muck 

 alone, imparts the dark green color to the leaves so in- 

 dicative of ammonia. It should be dug and be permitted 

 to dry out several months before being used, or it may 

 be mixed with lime at the rate of three or four bushels 

 to the ton of muck. There is no better absorbent for the 

 earth closet, the poultry house, the stable, the cow pen, 

 or the manure pile than salt-marsh muck. It may be 

 drilled in with any artificial fertilizer. Woods-earth, or 

 leaf mould, is still better as decayed vegetable matter, 

 and as a source of humus. 



SUPERPHOSPHATE OR ACID PHOSPHATE OF LIME. 



Phosphoric acid is, next to ammonia, or the nitrates, 

 the most important element of plant food, and it is also, 

 next to nitrogen, the earliest to become exhausted in 

 soil. It exists in all plants, in most soils, combined with 



