232 STATE BOAED OF AGRICULTUEE. 



acid, etc., but which are not avaihible for the growing phmt because they are in 

 an insohible condition. Tlie two most active agencies by which tliesc materials 

 are set free in a soluble form are water and carbonic acid ; but by far the most 

 energetic agent is carbonic acid. In a soil containing abundance of decaying 

 organic matter there is a large amount of carbonic acid, and in such soil decom- 

 position of inert minerals is comparatively rapid ; whereas, in a soil destitute of 

 organic matter the decomposition of mineral matter is very small. Although 

 muck may itself contain only a small amount of mineral matter, yet it furnishes 

 the gnawing tootli by whicli such mineral matter is set free in the soil for the 

 use of the growing plant. 



But the good ottices of carbonic acid are not confined to soil-decomposition. 

 About one-half of the weight of dry vegetable matter consists of carbon, and 

 the plant derives its chief supply of carbon from carbonic acid. The air con- 

 tains only a small amount of this gas, about one volume in 2,500, and it is found 

 that plants thrive better in an atmosphere which contains a larger j)roportion of 

 this gas. This larger proportion of carbonic acid is furnished to the plant by 

 the carbonic acid in the soil. Decomposing organic matter in the soil, there- 

 fore, enables the plant to obtain a larger proportion of mineral matter, and also 

 acts directly as food of the plant by furnishing an extra supply of carbonic acid. 



2. Muck is valuable because of its marked power to absorb and retain ammo- 

 nia. x\ very small amount of ammonia exists in the air, and from seven to nine 

 pounds to the acre are brought down yearly by the rain and snow. Tliis sub- 

 stance would rapidly escape from the soil if not absorbed and retained by the 

 vegetable mold. A certain amount of literally jJoatinfj ca2ntal in the air thus 

 becomes fixed capital in the soil by the agency of muck. 



3. It is a vast storehouse of fixed nitrogen. I have already stated that the 

 organic matter of muck contains about 2^ jier cent of fixed nitrogen, or 50 

 pounds to the ton. This amount of nitrogen is equal to that contained in more 

 than 300 pounds of nitrate of eoda or "Chili saltpetre," or more than 360 

 pounds of our ordinary saltpetre, or 5G0 pounds of guano. This enormous 

 amount of fixed nitrogen thus stored up in our swamp muck is a fact of very 

 great significance to agriculture. If we can devise any means by Avhicli this fixed 

 but inert nitrogen can all be made active and available, the millennium of agri- 

 culture will be within ear-shot I 



HOW TO USE MUCK. 



1. In regard to the method of using muck for the pliysical improvement of 

 the soil, I need offer no suggestions to the intelligent farmers before me. In 

 regard to the kind of muck to use, I may say that any kind may be used if it is 

 in the right physical condition, except one which is occasionally found which 

 contains sulphate of iron or copperas. You may suspect the presence of cop- 

 peras if a rusty scum forms on the water of a muck bed, and if the water turns 

 black when infusion of tea is poured into it. If this "vitriol" muck be com- 

 posted with lime, ashes, or marl, the sulphate of iron reacts with the lime, and 

 forms sulphate of lime or gypsum, and no harm will follow the rise of such 

 muck. But copperas in any considerable quantity is very injurious. Even ^ of 

 one per cent will render any soil barren. 



2. Comjjosts. — One of the most valuable uses of muck is in forming comjiost 

 with fermentable manures. For this purpose even the crude or cheesy muck 

 can be used. When one i)art of strong manure is mixed witli 3 or 4 parts of 

 muck, and the whole formed into a large compost heap, the whole mass jjasses 



