334 
Observation on Manures . &V. 
sition, and new compositions take place. Great quantities of car- 
bonic acid gas are evolved : alcohol is formed : then vinegar, which 
is alcohol united to oxygen. What do these products amount to, 
but carbon and hydrogen, and the oxygen imbibed from the atmos- 
phere ? For every drop of vinegar is made at the expence of a par- 
ticle of alcohol united to a particle of oxygen. 
In the case of the decomposition of animal substances, whether 
in the dry, or the moist way, no acid appears : we get azot, a fetid 
animal oil, swimming at the top of a volatile alkaline liquor, and 
sometimes concrete volatile alkali, or carbonat of ammonia comes 
over. The retort contains an animal charcoal, consisting of azot, car- 
bon loosely combined, the base of the prussic acid, and if bones be 
used, phosphat of lime. 
In this case, the azot, the lime, and the phosphorus, seem to be 
new combinations, the result of animal organization modifying 
chemical affinity. There are many districts of Pennsylvania, per- 
haps the best pasture land in it, that do not contain a particle of 
limestone. Such for instance as a great part of the county of Luzerne 
and the beech country comprehended between the north east branch 
of Susquehanna, the New York state line, and the Delaware. There 
is no finer grass country; but limestone is rare throughout the great- 
est part of this space. A calf bred up there, will have bones , 
that is phosphat of lime : his flesh will yield azot, either by distilla- 
tion, or by the nitric acid. Where does he get it ? The soil contains 
none ; the grass on which he feeds contains none, but the ox is 
chiefly composed of azot and phosphat of lime ! 
Hence it appears that about 99 parts out of a hundred of vege- 
table matter, consist of carbon and hydrogen of which the carbon 
far exceeds in quantity. 
Hence also, the pabulum or food of vegetables, can only be car- 
bon and hydrogen, or those substances which are easily decompose-^ 
able into carbon and hvdro^en. 
Hence animal matter is the best of manures, because, the carbon 
it contains is more easily disengaged, and the substance more easily 
decomposed than even putrescent vegetable matter. Hence it is 
that in steel furnaces and in case-hardening, animal charcoal i*s 
thought to aid the'operation ; the carbon of animal, being more ea- 
sily separated, than the carbon of vegetable charcoal. 
Hence we learn to distinguish, manures of nourishment, from ma- 
nures of stimulus , and from mechanical manures ; and we are taught 
that every vegetrdile and every animal substance when decompos- 
ed, f uraishes pabulum to vegetables : and that every such substance 
