136 
AMERICAN AGRICULTURIST. 
PLASTER AN!) AMMONIA. 
these masses of rock were broken up, pul¬ 
verized, decomposed, producing a mass of 
soil. Different kinds of rocks, such as gran¬ 
ite, limestone, &c., produced different kinds 
of soil; and at some period every part of the 
surface of the earth has been covered by 
vast quantities of moving water, which have 
still farther ground and worn and mingled, 
and sometime separated these decayed 
masses of rocks, soils, &c., and left them as 
we now find them, sometimes in masses of 
pebbles or gravel with finer portions, some¬ 
times bodies of sand, and again beds of clay, 
and in other places all these mingle together. 
These are however, more frequently deposi¬ 
ted in layers lapping upon or underlying 
each other. 
This arrangement is one of great impor¬ 
tance in connection with the subject of drain¬ 
ing. If we examine the side of a well while 
it is being dug, or the sides of a canal, or a 
railway excavation through a high bank of 
earth, we shall see good illustrations of this 
general arrangement below the surface. 
There are thin beds of clay, perhaps but a 
fourth of an inch thick, and others may be 
many inches or feet, and with these can also 
be seen beds of gravel, loam, &c. These 
beds do not lie in regular layers, like boards 
one above the other, but are very variable 
in their form ; sometimes horizontal or flat 
but more frequently inclined or curved. 
Fig. 1 will give an idea of some of these ar¬ 
rangements. 
Fig. 1. 
From a to e we have a thin layer of sur¬ 
face soil, mingled with organic matter. ATis 
a loam subsoil, and the surface from a to b is 
the same with the addition of vegetable 
matter. O and rn are beds of clay, and over 
these we have clayey surface soils. Z7 is a 
gravelly loam with similar surface soil from 
c to d. These separate beds may be a few 
feet only in length, or they may each extend 
many miles. 
Fig. 2 represents a valley, with portions of 
the adjacent hill-side lands. Different layers 
of clay, loam and gravel are shown coming 
out upon the side of the hills, and giving 
character to the thin layer of surface soil 
which extends over the whole. [The de¬ 
pressions, like the valley here shown, may 
be supposed to have been produced by cur¬ 
rants of water washing out hollows. So 
the sides of the hills were probably washed 
away as shown in Fig. 3.] 
Fig 3 gives a section of a hill, in which a 
similar arrangement is shown. In this, y is 
a bed of sand which may be found by digging 
down between e and /. These layeis of 
sand are very frequent, and are dug out for 
building. The same may be said of the bed 
of gravel between d and e. 
Fig. 4 shows a still different arrangement, 
in which l is clayey loam, enclosing beds of 
gravel and clay ; c a curving bed of clay ; p 
a porous mass of gravelly soil, of large ex¬ 
tent ; w is an artificial or artesian well; s a 
natural spring, and r the underlying rock. 
There is another arrangement, however, 
which is much more frequent, and which de¬ 
serves a careful examination. These differ¬ 
ent beds of porous and compact soil or rock 
are generally inclined at a greater or less 
angle, as shown in the following figure : 
We can readily see here what is the effect 
of such an arrangement upon the surface soil. 
Over the finer, more compact subsoil, as be¬ 
tween e and/, l and m, the water will sink 
less readily than over the gravelly portions 
between c and d.kandl; while over the 
compact clay portions between b and c, d 
and e, i and k, m. and n, we should have 
wet, heavy land. Vtfe have seen single fields 
on which a dozen different layers came up 
to the surface and produced as many varia¬ 
tions in the composition of the soil, and an 
equal number of wet and dry spots ; and, 
again, we have seen places where some of 
these single beds occupied several miles of 
surface. Half a dozen farms may lie upon 
the upper part of each of these divisions, and 
in other cases we shall find all these beds of 
different soil cropping out upon a single 
farm. [To be continued.'] 
PROVIDE FOR THE TURNIP CROP. 
Next month will be the time to put in seed for 
a large supply ol roots for feeding next Winter. 
Do not use up all the ground for other purposes. 
Five hundred to a thousand bushels of ruta baga 
turnips can be grown on an acre, and how can 
you get more or better Winter food for your stock 1 
VALUABLE EXPERIMENTS BY PROF. PORTER. 
One of the settled points in the theory 
and practice of soilculture is, that ammonia 
is a valuable fertilizer for all, or nearly all 
growing plants. It is this substance that 
gives so high a value to Peruvian Guano, to 
urine, to horse manure, &c. Every one is 
acquainted with ammonia as it escapes from 
the stables, from chamber slops that have 
stood for a few hours, and from “ Hartshorn 
smelling bottles.” It is also well known 
that this is a very volatile substance, which 
escapes into the air rapidly and is lost. To 
“ fix” and retain the ammonia in manures is 
an important operation. This may be read¬ 
ily done by the addition of a little dilute 
acid, such as sulphuric acid, (oil of vitriol,) 
hydrochloric acid, (called also muriatic acid, 
and spirits of sea salt.) The inconvenience 
of handling these acids, and their expense, 
has always been an objection to their gener¬ 
al 
Fore||pveral years past we have recom¬ 
mended adding to all kinds of animal ma¬ 
nures a frequent sprinkling of sulphate of 
lime, usually called gypsum, or plaster of 
Paris. This is a compound substance, made 
up of sulphuric acid and lime. When 
brought in contact with substances contain¬ 
ing ammonia, the ammonia takes the sul¬ 
phuric acid away from the lime, and forms a 
new compound, called sulphate of ammonia, 
(sulphuric acid and ammonia,) which not be¬ 
ing volatile, remains in the manure to be 
given up to plants. 
But it has been asserted by many that the 
dry plaster added to a manure heap, or to 
guano, will not unite with the escaping am¬ 
monia and retain it. This is an important 
point, and although we had settled the mat¬ 
ter to our own satisfaction, by a number oi 
experiments made three or four years since, 
last winter we requested Prof. John A. Por¬ 
ter, (Professor of Organic Chemistry in 
Yale College,) to make such experiments as 
might be necessary to settle the question. 
We give his reply below. It will be observ¬ 
ed that the mass of horse manure experi¬ 
mented upon, was placed in the same condi¬ 
tion as a heap of stable manure, viz.: a moist 
or fermenting portion below, with a dry por¬ 
tion over it. We will here repeat our oft- 
given advice, to always have at hand a bar¬ 
rel of plaster, and mix a small portion of it 
with every portion of animal manure made 
in the stables or yards. There is, in our 
opinion, no doubt as to the practical advan¬ 
tage of this course. 
To the Editor of the American Agriculturist : 
Sir : In reply to your inquiry, I would state 
that I sometime since undertook to settle the con¬ 
ditions ol the absorption of ammonia by sulphate 
of lime, or gypsum, by direct experiment. 
Before giving the result, let me premise, for the 
sake of clearness on what is to follow, that am¬ 
monia always escapes in company with carbonic 
acid, in case of the fermentation of manures, and 
indeed in all cases of advanced decay or putrefac¬ 
tion. It is also in tne form of carbonate of am¬ 
monia that it exists in the air. The point then 
to be decided is, the action of gypsum^or^sulphat.e 
of lime, on carbonate of ammonia. 
