46 
Farmyard Manure. 
system, tliat hall" of the roots and 100 tons of hay are consumed 
at the homestead, and that the whole of the straw of the corn- 
crops is retained at home as food and litter. Let it further be 
assumed that 12 horses have corn equal to 10 lbs. of oats per 
head per <lay, and that about 10.9. per acre are expended in the 
purchase of cake for feeding stock. Under these circumstances 
the preceding table shows the amounts of the matters enumerated 
entering into the home manures of the farm in the course of the 
year. 
These are, as nearly as can be reckoned, the average amounts 
of the constituents enumerated that would contribute to the home 
manure of the farm annually. But farmyard manure in the 
fresh state and before it has undergone much decomposition, con- 
tains about 70 per cent, of water, or 7 parts of water to 3 parts of 
dry matter. The 574,645 lbs. of dry matter would thus be com- 
bined with 1,340,838 lbs. of water, making together 1,915,483 
lbs. = 855 tons (or an average of about 8|- tons for each of the 100 
acres of root-crop), oifresli wi-decomposcd dung. In this state its 
composition, per cent, and per ton, would be as follows : — 
Total Dry 
Matter. 
Total 
Mineral 
Matter. 
Phosphoric 
Acid, 
reckoned as 
Phosphate 
of Lime. 
Potash. 
Nitrogen. 
Nitrogen 
calculated as 
Ammonia. 
Per cent 
30-0 
2-77 
0*50 
0-53 
0-64 
0'77 
lbs. 
lbs. 
lbs. 
lbs. 
lbs. 
lbs. 
Per ton 
672 
62-0 
ll-l 
12-0 
14-3 
17-3 
This is the composition of the fresh undecomposed dung cal- 
culated from the average composition of the matters which are 
supposed to enter into it. 
The proportion of total dry matter given above is rather higher 
than the average of results obtained at Rothamsted with good 
box-dung ; it is also higher than the average of the results given 
by Boussingault ; but is lower than the amount given by Pro- 
fessor Voelcker for fresh dung. 
The amount of mineral matter found by analysis in farmyard 
manure is generally at least oncc-and-a-half or twice as much as 
that contained in the clean food and litter, owing to the admix- 
ture of dirt. The amount of mineral matter in fresh dung 
due to the mineral constituents of the food and litter will pro- 
bably seldom be much more than 3 per cent., but in rotten 
dung that has not Avasted by drainage it may be considerably 
more. 
The calculated amount of nitrogen given above is almost 
exactly the mean of the results of Boussingault and Voelcker on 
