On Permanent and Tem-porarxj Meadows and Pastures. 213 
2-787 tons of dry hay. The value of farmyard-manure being 
about 8s. \hd. per ton, the expense will be 109s. 7|c?. per acre, 
whilst that of the chemical nitrogenous manure, as we have 
seen, was only 50s. 3^rf. There is therefore a marked advantage 
in using a chemical manure, by which we can make the various 
economies which I have pointed out ; especially as with farm- 
yard-manure we are unable to alter the percentage of any 
one of its constituents without reducing the rest at the same 
time. 
If, on the other hand, we compare the composition of 1 ton 
of hay with that of 5 tons of farmyard-manure, we shall see that 
the latter contains an excess of several elements which will ot 
necessity remain unemployed : — 
In 1 Ton of 
Dry Hay. 
In 5 Tons of 
Farmyard- 
Manure. 
In 1 Ton of 
same. 
Phosphoric ticid 
Potash 
Magnesia 
lbs. 
38-43 
15-94 
52-86 
32-48 
618 
lbs. 
64-96 
40-32 
56-00 
109-76 
20-16 
lbs. 
12-98 
8-06 
11-20 
21-95 
4-03 
This calculation is based on the average composition of well- 
rotted farmyard-manure, taken from the tables of Wolff. 
We have seen that it is sufficient to supply 6'72 lbs. of nitric 
nitrogen to produce 1 ton of hay, while 6 tons of farmyard- 
manure contain, if my analysis is correct, 58-24 lbs. too 
much nitrogen ; and yet, notwithstanding this excess, farm- 
yard-manure is less efficacious than the manure I advise, because it 
does not give in the required condition the 6*72 lbs. of nitrogen 
which are necessary. Moreover, it contains phosphoric acid, 
lime, and magnesia in great excess. Farmyard-manure, then, 
is far more suitable for the cultivation of arable than of grass- 
lands ; for in ordinary cultivation, the plough mixes it with the 
mass of the soil, and the succession of crops allows of the suc- 
cessive utilisation of all the elements it contains. This im- 
portant conclusion is borne out by practical experience. 
Messrs. Lawes and Gilbert, in the experiments to which I 
have previously had occasion to allude, have maintained a piece 
of grass-land by applying to it annually for 8 years 13 '47 tons 
of farmyard-manure to the acre. At the end of this time they 
had to discontinue the use of farmyard-manure, because the 
mass of organic matter which had accumulated in the soil 
made them fear that vegetation might thereby suffer. The 
average return of the first mowing for the 8 years was 4798-9 lbs. 
