32 



On the Chemieal Properties of Soils. 



appears to influence the amount of ammonia which the latter is 

 capable of retaining. 



14. In no instance is the ammonia absorbed by soils from 

 solutions of free ammonia, or from ammoniacal salts, so completely 

 or permanently fixed, as to prevent water from washing out ap- 

 preciable quantities of the ammonia. 



15. The proportion of ammonia, however, which is removed 

 in the several washings, is small in proportion to that retained by 

 the soil. 



16. The power of soils to absorb ammonia from solutions of free 

 ammonia, or from solutions of sulphate of ammonia or chloride of 

 ammonium, is thus greater than the power of water to redissolve it. 



17. In practice no fear need be entertained that in ordinary 

 years heavy showers of rain will remove much ammonia from 

 ammoniacal top-dressings, such as sulphate of ammonia, soot, 

 guano, and similar manures, which are used by farmers for wheat, 

 barley, and oats. 



18. On the other hand, in very rainy seasons, appreciable 

 quantities of ammonia may be removed from land top-dressed 

 with ammoniacal manures, even in the case of stiff clay soils. 



Royal Agricultural College, Cirencester, 

 June, 1860. 



London : Printed by WILLIAH CLOWES and SONS, Stamford Street, 

 and Charing Cross. 



