38 Farmyard Manure. 



An imperial gallon of this water was found to contain 84*88 

 grains of dry residue (dried at 220 F.), consisting of 



Organic matter, and a little water of com- ) AQ r\c\ 



bination } 



Carbonate of lime 



Sulphate of lime 



Phosphate of lime, with a little oxide of iron 



Carbonate of magnesia 



Chloride of sodium 



Potash 



Silica .. .. 



84-88 



The amount of organic matter in this water is very great ; it 

 arises from the great excess of decomposing organic remains in 

 the soil, and imparted to the water a yellow colour and disagree- 

 able smell, not unlike the smell of water in which flax is steeped. 

 It will be further observed that even pure rain-water is capable 

 of rendering soluble a considerable quantity of all those mineral 

 constituents which are found in the ashes of our crops, and there- 

 fore are necessary to their growth. 



2. Filtration experiment made with the drainings of a dung- 

 heap composed of fresh-mixed farmyard manure. Having ascer- 

 tained in the previous filtration experiments that a soil containing 

 a good deal of clay and lime is capable of removing from com- 

 pound manuring substances all the more valuable fertilising con- 

 stituents, I was anxious to determine to what extent soils deficient 

 in both clay and lime possessed the property of retaining fer- 

 tilising substances from drainings of dung-heaps. The compo- 

 sition of the liquid used for this experiment is given above ; it is 

 the same liquid collected from a fresh dung-heap which in a 

 gallon contained 1357*74 grains of solid matter. 



The soil selected for experiment was a light, sandy, red- 

 coloured, very porous soil, containing, as will be seen by the 

 following analysis, only little clay and still less lime, but a good 

 deal of organic matter. It was submitted to a minute and careful 

 mechanical and chemical analysis, and furnished the results 

 embodied in the subjoined tables : 



1. Mechanical Analysis. 



Moisture 3*45 



Organic matter and water of combination 13'94 



Coarse white quartz sand .* 47'00 



Fine red sand and a little clay deposited from water on j i g.go 



standing 5 minutes / 



Coarse clay deposited on standing 10 minutes . . . . 2*82 

 Pine clay deposited from water on standing for 1 hour 6 '30 

 Finest clay kept in suspension in water after standing \ ^.^ 



longer than 1 hour / 



100-00 



