34 MANURES, 



ammonia, I beg, in conclusion, to point out the large quantity of 

 carbonate of lime in the filtered liquid as worthy of notice. This 

 large amount of carbonate of lime is easily explained by the pres- 

 ence of much lime in the soil. Before filtration the liquid contained 

 only about 11^ grains of carbonate of lime, and after filtration as 

 much as nearly 80 grains. Thus while potash and ammonia are 

 absorbed by the soil, lime is dissolved and passes into the liquid, 

 which is filtered through the soil. Not only is the quantity of car- 

 bonate of lime considerably increased in the filtered di'ainings, but 

 that of sulphate of lime in a minor degree also. 



It is highly satisfactory to me to find the observations of Profes- 

 sor Way, with respect to the relative power of soils to retain 

 ammonia, potash, soda and lime, confirmed in my experiments with 

 a liquid containing a number of fertilizing agents required by our 

 crops. 



Before describing the next filtration experiments, I may state 

 that I have thought it a matter of some interest to examine what 

 amount of solid organic and inorganic matter to a given quantity 

 of pure water would dissolve from the soil, the composition of 

 which has been stated above. Accordingly, one part by weight 

 of subsoil, and one part of surface-soil, were mixed with four parts 

 by weight of distilled water, and the whole being occasionally 

 stirred up, left to subside for twenty-four hours, after which time 

 the water was filtered from the soil, and carefully analyzed. 



An imperial gallon of this water was found to contain 84.88 

 grains of dry residue (dried at 220° Fah.), consisting of — 

 Organic matter, and a little water of combination, 

 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 color, and disagree- 

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



