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sulphate of ammonia and carbonate of lime. The sulphate 
of ammonia is not so volatile as the carbonate, and yields 
nitrogen gradually to the growing plants. The effects of 
gypsum, however, are not immediately visible, but are slow 
and permanent. A small quantity, if strewed in the stables 
of horses, not only destroys the effluvia, but a valuable 
manure is thus formed. This salt really abounds in the stra- 
tum described, and can be had at so cheap a rate, that it 
must be worthy of trial. Lord Leicester presented Mr. 
Grisenthwaite with a piece of plate, for his exertions in in- 
troducing it. Liebig states, that if a field be strewed with 
gypsum, and then with putrefied urine, or the draining of 
dunghills, all the carbonate of ammonia will be converted 
into the sulphate, which will remain in the soil. By judicious 
draining of this stratum a considerable quantity of water 
may be cut off from passing to the lowest portion of the clay 
by Elkington's plan: the water falls on the limestone, and 
breaks out at the bottom of it : a deep drain cut parallel, or 
in a north and south line, generally would intercept it. 
The Lower Red Sandstone^ or Pontefract JRock, wherever 
it contains marl, requires the same mode of farming, its marls 
require deep draining and subsoil ploughing ; the sand beds 
upon it are infertile, and would be greatly improved by the 
admixture of marl. This rock contains no gypsum. 
So much, then, for the existing state of farming on the 
Magnesian Limestone. In fine, the great secret in agriculture 
is to follow the indications of Providence. He has, however, 
ordained a great circle of transmutations. Vegetables collect 
[food from inorganic bodies, while animals derive sustenance 
[from vegetables, the decay of both affords a fresh supply of 
t nutrition to vegetables. The atmosphere is a vehicle for the 
supply of one substance, the earth of another, and one re- 
^maining constituent has been left to be adduced by man. In 
some countries man does follow the suggestions of the laws 
