134 On the Composition of Waters of Land-Drainage. 



1857-58 and previously, 300 lbs., 200 lbs., and 100 lbs. re- 

 spectively, and 200 lbs. bone-asli, and 150 lbs. sulphuric acid 

 (spec. grav. 1'7). 



Plot 6. — The same mineral manures as Plot 5, and 200 lbs. 

 of ammoniacal salts (equal parts of sulphate and muriate of 

 ammonia of commerce), containing 41 lbs. of nitrogen. 



Plot 7. — The same mineral manures as on Plot 5, and 400 lbs. 

 of ammoniacal salts, containing 82 lbs. of nitrogen. 



Plot 8. — The same mineral manures as on Plot 5, and 600 lbs. 

 of ammoniacal salts (containing 123 lbs. of nitrogen). 



Plot 9. — The same mineral manures as on Plot 5, and 550 lbs. 

 nitrate of soda (containing 82 lbs. of nitrogen). 



Plot 10. — Without mineral manure, and 400 lbs. ammonia- 

 salts (containing 82 lbs. of nitrogen). 



Plot 11. — Superphosphate (200 lbs. of bone-ash, and 150 lbs. 

 sulphuric acid, and 400 lbs. ammoniacal salts). 



Plot 12. — Superphosphate, and 366^ lbs. sulphate of soda, and 

 400 lbs. ammoniacal salts. 



Plot 13. — Superphosphate, and 200 lbs. sulphate of potash, and 

 400 lbs. of ammonia-salts. 



Plot. 14. — Superphosphate, and 280 lbs. sulphate of magnesia^ 

 and 400 lbs. ammonia-salts. 



Plot 15. — Mixed alkalies, and 200 lbs. bone-ash, and muriatic 

 instead of sulphuric acid, and 400 lbs. sulphate of ammonia one- 

 half of the plot, and the other half used alkalies and superphos- 

 phate, and 300 lbs. sulphate of ammonia, and 500 lbs. of rape- 

 cake. 



Plot 16. — Mineral manures and 800 lbs. ammonia-salts 1852- 

 64. Unmanured 1865 and since. 



The drainage-waters, it will be seen, were collected from plots 

 of the same field upon which wheat had been grown from year to 

 year since 1844. These plots as regards manure Avere very 

 differently treated. 



From Plot 2 Ave have the land-drainage of the portion of field 

 which had been manured every year with about 14 tons of farm- 

 yard-manure. 



Plots 3 and 4 had been left unmanured for a great number of 

 years. 



Plot 16 had been highly manured both Avith mineral and am- 

 moniacal manure previous to 1865, and left unmanured since 

 that year. 



On Plots 5-9 a fixed quantity of a mixed mineral manure. Avith 

 A'ariable quantities of ammonia-salts and nitrogen in the form of 

 nitrate of soda had been applied, and 



On Plots 10-14 a fixed quantity of ammonia-salts Avith 

 different kinds of mineral manures were used. 



