ure with salt would be advisable.

_The amount of lime_ required _by plants_ is, as was before observed,
usually small compared with the whole amount contained in the soil;
still it is not unimportant.

OF LIME.
25 bus. of wheat contain about 13 lbs.
25 " barley " 10-1/2 "
25 " oats " 11 "
2 tons of turnips " 12 "
2 " potatoes " 5 "
2 " red clover " 77 "
2 " rye grass " 30 "[AH]

[What is the best guide concerning the quantity of lime to be
applied?

What is said of the sinking of lime in the soil?

What is plaster of Paris composed of?

Why is it called plaster of Paris?]

The amount of lime required at each application, and the frequency of
those applications, must depend on the chemical and mechanical condition
of the soil. No exact rule can be given, but probably the custom of each
district--regulated by long experience--is the best guide.

_Lime sinks in the soil_; and therefore, when used alone, should always
be applied as a top dressing to be carried into the soil by rains. The
tendency of lime to settle is so great that, when cutting drains, it may
often be observed in a whitish streak on the top of the subsoil. After
heavy doses of lime have been given to the soil, and have settled so as
to have apparently ceased from their action, they may be brought up and
mixed with the soil by deeper plowing.

_Lime should never be mixed with animal manures_, unless in compost with
muck, or some other good absorbent, as it is liable to cause the escape
of their ammonia.

PLASTER OF PARIS.

_Plaster of Paris or Gypsum_ (sulphate of lime) is composed of sulphuric
acid and lime in combination. It is called 'plaster of Paris,' because
it constitutes the rock underlying the city of Paris.

[Is it a constituent of plants?

What else does it furnish them?

How does it affect manure?

How does it produce sorrel in the soil?

How may the acidity be overcome?]

It is a constituent of many plants. It also furnishes them with
sulphur--a constituent of the sulphuric acid which it contains.

It is an excellent absorbent of ammonia, and is very useful to sprinkle
around stables, poultry houses, pig-styes, and privies, where it absorbs
the escaping gases, saving them for the use of plants, and purifying the
air, thus rendering stables,