Washington sentinel., 1854-01-01
Aaritnltnral.
From the Maine Farmer.
Wfl Dry Gypsum Absorb Amm0niai

/ Some OF the best chemists OF the age have
1 taught that when fermentation is going on in
your manure heaps and the ammonia is flying
4 off in the air, which is easily detected by the
odor, if you scatter on little ground plaster,
you will prevent any further escape of the am
monia, which is very important ingredient of
manure. That there will be change of ingre-
dients-the sulphuric acid in the plaster unit
ing with the ammonia, and settling down in a
fixed state, while the carbonic acid leaves the
ammonia and unites with the lime Of the plas-
ter and forms carbonate of lime.
Now we have always considered this the true
doctrine, for we have sprinkled it on ferment
i ing heaps of horse manure, and thereby de-
stroyed the odor We have also scattered it
in and about privies, and neutralized the of
/ fensive odors thereof, for time, and without
any further examination supposed the above
/ theory correct. The editor Of the Rural Ne,c
Yorker, however, in the 49th number of his
4 paper, controverts this theory, and denies that
j plaster will thus unite with ammonia, unless it
| be dissolved. He bases his assertion upon the
following experiment, which he thus describes.
"a short time since we were at the house of
4 such person, and were discussing this sub
ject with him. He is quite a>scientifc farmer
and writer and had been using guano and
plaster. There was some Of both left in the
/ bdIus Jul dlSuluCHlo III idNOl VI tuC tuC-
ory, said we, are good, but let us apply
practical test. Here is some guano and plas-
| ter. There is probably carbonate of ammonia
| flying off from the guano let us see what effect
| mixing plaster with it will have If your the
ory is correct it will of course stop the exhala-
tion.' We put the two together, rubbed them
briskly between the hands, moistened with a
little water, and then applied the mixture to
the nostrils of our friend He quickly jerked
his head away. Instead of fixing the ammo
MIA, the plaster aided the decomposition of the
guano, and the ammonia was driven off with
considerable rapidity. This simple test salts
fed our friend and we would recommend all
who are sceptical on the point to make the
experiment for themselves.
Scattering dry or moist plaster on the ma
nure heap, then, is Of no use. But if we
could only dissolve it, it would be just the very
thing we want. Cannot this be done? 1t is
true that something like four hundred pounds
Of water are required to dissolve one pound of
plaster, but the water could be used over and
over again, the manure taking the sulphate of
lime from the water as it filtered through it.
The water in the tank should always be kept
saturated with plaster, and no water should
ever be allowed to get on to the heap that did
not contain plaster in solution. In this way
plaster sufficient to form considerable guam
tity of sulphate of ammonia might be placed in
the heap without rendering the manure too wet
for fermentation, inasmuch as the carbonate Of
lime resulting from the transformed sulphate Of
lime, would materially assist decomposition.
On the other hand, we have the experiments
Of another practical man, Professor Campbell
Of North Carolina, by which it would seem that
plaster, in a dry state, does actually absorb, or
rather decompose carbonate of ammopie while
flying off from fermenting manure. he gives
detail Of his experiment in the Southern
Planter, in the following words:
81 am well aware how little confidence far
mers, generally, place in chemical theories and
laboratory experiments before their claims have
been fully established by the unerring test of
practice. Hence, for the satisfaction and benefit
Of those whom it may concern, have Just
concluded an experiment independent Of labo-
ratory, crucible and retort-an experiment in
volying nothing new or remarkable in the eye
of one familiar with the principles Of chemical
science, yet important in its practical bearing.
1t was conducted as follows:
"a barrel was filed with fresh scrapings from
the stalls of horses. Over the manure, as
thrown in, a little ground plaster was sprinkled
from time to time. After the barrel had been
compactly filled, it was allowed to stand some
weeks until it had gone through the heating
process, which always takes place when newly
collected manure is thrown into heaps. But
during this heating or fermentation, las it may
with propriety be called there was none of that
'vapor' of strong odor which ordinarily arises
from fermenting manure heaps. When the
mass had become COOL clean rain water was
passed through it and collected at the bottom
of the barrel. This water was found to contain
one Of the elements Of plaster and one of the
volatile substance carbonate of ammonia)
above alluded to. On emptying the BARREL a
white powder, looking very much like plaster,
was found mingled with its contents. But when
tested, this powder was found to contain only
one Of the elements of plaster; while it con-
tanned also one element of the volatile carbo-
nate of ammonia just mentioned"
In order that those who are not familiar with
the principles of chemistry may understand the
foregoing experiment, and fully appreciate its
results, a little explanation is necessary.
The volatile matter which escapes so rapidly
from heaps of manure, and the presence Of
which is perceived by its odor about stables
where horses are fed, is called by chemical
writer's carbonate of ammonia" consisting of
carbonic acid and ammonia combined.
Plaster (gypsum) is according to chemical
nomenclature, a sulphate of lime, i.e. sulphuric
acid and lime combined. Liebig says, Scar
Donate Of ammonia and sulphate Of lime (gyp-
sum) cannot be brought together at common
temperatures without mutual decomposition.
The ammonia enters into combination with the
sulphuric acid and the carbonic acid, and the
carbonic acid with the lime, forming compounds
which are not volatile, and consequently desti-
tute of all smell" Thus we get two new COM
pounds, namely, carbonate of lime in very fine
powder, and sulphate of ammonia, which is not
volatile, and of course not liable to be lost in
the same way as the carbonate of ammonia.
This sulphate, however, is readily dissolved in
water. Hence, in the experiment above de-
tailed, it was carried out in solution by the
water and manure.
What points, now, are illustrated by the re-
suits Of this experiment? First, that ground
plaster sprinkled about stables and over fresh |
manure, as it is collected into heaps, will arrest
the escape of the fertilizing matter, Secondly, |
that if this manure be left unshcltered from the |
rain, the sulphate of ammonia generated by |
~ IF tho rlo ctar xvu ha oh