Liquid Manure. 25 



compounds of ammonia are brought in contact with them, are 

 still to some extent soluble in water. This fact explains likewise 

 the different results which are obtained in ascertaining the ab- 

 sorptive properties of soils for ammonia when limited quantities 

 of strong or very dilute solutions of ammonia are employed in 

 such experiments. If, therefore, 1000 grains of soil absorb in 

 one particular experiment say "55 of a grain of ammonia, it does 

 not follow that this quantity expresses the maximum proportion 

 of ammonia which that soil is capable of taking up. 



3. In conformity with other experiments, a larger proportion 

 of lime was found in the filtered liquid manure than in the liquid 

 before coming in contact with the soil. 



4. The proportion of magnesia and sulphuric acid in the 

 filtered liquid likewise is larger than in the original manure. 



4. It will be noticed that the amount of potash and chloride 

 of potassium in the Tiptree liquid manure is very small. In- 

 stead of diminishing, when brought into contact with soil, as in 

 all the other experiments, the amount of potash in a gallon of the 

 liquid manure left in contact with soil for three days was larger 

 than in the liquid before coming in contact with the soil. It 

 thus appears that the soil contained, like most clay soils, 

 abundance of alkaline silicates, which yielded to liquid manure a 

 certain small amount of potash and also of soda, in addition to 

 the alkalies naturally contained in the manure. 



5. In conclusion, I would notice that the proportion of phos- 

 phoric acid in the liquid manure, after contact with this soil, is 

 very nearly the same as that contained in the original liquid. 

 Scarcely any absorption of phosphoric acid thus took place, or, 

 perhaps, more correctly speaking, the compounds of phosphoric 

 acid which are formed in the soil are so inconsiderable in amount 

 that there is sufficient water in a gallon of liquid to keep them 

 nearly entirely in solution. 



CONCLUSIONS. 



With a view of saving trouble to readers who are not disposed 

 to go through all the chemical evidence contained in the pre- 

 ceding pages, I briefly notice in conclusion the chief points 

 of interest which may be gathered from this account of my 

 experiments. 



1. Liquid manure, in contact with soil, undergoes a number 

 of chemical changes. 



2. These changes are greater in the case of clay and calcareous 

 soils than in the case of sandy soils. 



3. Passed through clay, loamy, and calcareous soils, liquid 

 manure leaves a considerable quantity of ammonia in the soil. 



4. Under the same circumstances, liquid manure parts like- 

 wise with potash and phosphoric acid. 



