268 
FERTILIZERS. 
which the crop is to be grown. Shell fish, as clams, scollops and muscles, though not equal to 
alewives and herring for manures, are still very valuable. 
12. Fertilizers from the Farm-Yard. 
These are not so purely animal as the preceding; they consist of animal matters, intermixed 
more or less with fine fodder, changed in various degrees by the organs of digestion. The 
value of all these products is variable ; it depends entirely upon the food : rich food gives an 
active fertilizer. The excrements of geese fed upon grass is less valuable than if they are fed 
upon corn. Cattle receiving a quantity of corn meal or oil cake, will furnish a manure far 
more active than when fed on hay. Those fertilizers are all bulky and heavy, and their use 
is commonly confined to the premises upon which they are produced ; their bulk, however, 
serves an important end, it operates mechanically, and promotes a loose, friable condition of 
the soil and the pentration of air. 
The application of farm-yard manures is well understood : they have been, and always will 
be, the great sources from whence the farmer will derive his fertilizers ; they have few contin¬ 
gencies in their application. If the season is dry their presence in the soil becomes a source 
of moisture, and a well manured field is more independent of rain than when manured with 
richer kinds, as guano. The proper preservation of manures of this description is well un¬ 
derstood, though it is not always acted upon. The crops to which they may be directly ap¬ 
plied are well determined, and the most profitable quantity, though there are fewer restrictions 
than in the case of the active and energetic manures. There is one point necessary to be at¬ 
tended to ; the manure heap should be under cover, and it should never stand through the 
summer to ferment and burn out. Much of these matters, in cities, where they accumulate in 
close boxes, are injured, especially the excrements of horses. Another practice should be 
avoided here ; quicklime should not be put into the heaps, but gypsum ; with the former am¬ 
monia will be lost. The improved system of building barns and out-houses, together with the 
enclosures, is doing much to save the valuable parts of fertilizers. The more common and free 
use of gypsum in stables, yards and all places where volatile substances are escaping, seems 
very desirable, and even necessary, in order to save the nitrogenous matters, so essential to the 
perfection of seeds and grain. Plaster is preferable to sulphuric acid, which is often recom¬ 
mended, being less expensive and less liable to create accidents by spilling. 
The ash of the excrements of the horse has the following composition : 
Silica,.. 3 '20 
Phosphate of lime,. O’40 
Carbonate of lime,. l - 50 
Phosphate of magnesia and soda,. 2*90 
8 - 00 Jackson. 
