140 Report on Trials of Plows. 



equal portions of ammonia. Tlius, the total amount of ammonia 

 absorbed by 1,000 grains of soil was, in the case of the 



1. Calcareous soil 1.5193 grains of ammonia. 



2. Fertile loamy soil , 1.5363 " 



3. Clay soil 1.1240 " 



4. Sterile sandy soil 1.5220 " 



5. Pasture land 1.5217 " 



Dr. Voelcker next proceeded to verify these results by repeat- 

 ing the experiments in another form. He made four solutions of 

 ammonia of varying degrees of strength, and used the same soil — 

 a stiff calcareous chiy — in all his experiments. 



Per 1,000 grains. 



Solution No. 1 contained 44.38 grains of ammonia per gallon, or. . .634 



No. 2 " 21.28 " " " .. .304 



No. 3 " 12 32 " " " .. .176 



No. 4 " 6.16 " " " .. .088 



The soil was saturated with each of these solutions, when it 



was found that 1.000 grains of the soil thus absorbed in 



No. 1 1 .32 grains of ammonia. 



No 2 64 '• " 



No, 3.... 26 " " 



No. 4 10 " 



These experiments show conclusively that all soils have the 

 power of absorbing ammonia from its solutions; that no soil can 

 abstract all the ammonia from a solution; that all soils can take 

 up a greater relative amount of ammonia from strong than from 

 weak solutions of ammonia; hence a soil which had absorbed as 

 much ammonia as it would from a weak solution took up a fresh 

 quantity of ammonia when it Avas brought into contact with a 

 stronger solution. 



Dr. Voelcker's experiments further showed that soils were 

 equally disposed to appropriate ammonical salts as they were to 

 absorb ammonia itself. 



He next endeavored to ascertain how far the soils were disposed 

 to part with the ammonia thus absorbed to the rain water which 

 percolates through them. In order to accomplish this, a quarter 

 of a pound of a soil, saturated with ammonia, was well shaken in 

 7,000 grains of distilled water. It was allowed to settle for three 

 days, when the clear liquor was carefully decanted, and tiie 

 amount of water contained in it exactly ascertained. The soil 

 thus washed was again shaken in a well stoppered bottle with 

 7,000 o-niins of fresh distilled water, and settled and decanted 



