134 
DmiiKifje of Wkittlcsca Merc. 
appears to influence tlie 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 c/reater 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, 
barlev, 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. 
VIII. — The Drainage of Whittlcsca Mere. By W. Wells. 
At various intervals within recent years there have appeared, 
either as articles in this Journal or as independent works, notices 
bearing more or less directly on the subject of the large tract of 
country known as the Great Level of the Fens. 
Some of these notices have been most ably written, and have 
taken comprehensive and scientific views of the nature of the 
Fens, of the past and present systems of draining and cultivating 
them, and of the large question of their geneial improvement, as 
contrasted or going hand in hand with the marvellous strides 
that have been made of late years in the cultivation of what a 
fenman would call the Upper Country. 
It has been suggested that, as a sequel to the notices alluded 
to above, or rather as an illustration of the subjects which they 
have treated in a general and comprehensive manner, a short 
account of the draining of Whittlesea Mere would be appro- 
priate and not uninteresting ; and it is hoped that although no 
great addition to the details of scientific or practical agriculture 
can be offered in giving this account, it will yet be considered 
that a record of the blotting out from the map of England of one 
