The Elements of Agriculture A Book for Young Farmers, with Questions Prepared for the Use of Schools - George E. Waring (bill gates books to read txt) 📗

next become a constituent of an animal, or, with the decomposed dead animal, may form a part of the soil. If the animal should fall into the sea he may become food for fishes, and our atom of nitrogen may form a part of a fish. That fish may be eaten by a larger one, or at death may become food for the whale, through the marine insect, on which it feeds. SECTION 1 (THE PLANT) CHAPTER III (HYDROGEN, OXYGEN AND NITROGEN)__NITROGEN Pg 18

 

After the abstraction of the oil from the whale, the nitrogen may, by the putrefaction of his remains, be united to hydrogen, form ammonia, and escape into the atmosphere. From here it may be brought to the soil by rains, and enter into the composition of a plant, from which, could its parts speak as it lies on our table, it could tell us a wonderful tale of travels, and assure us that, after wandering about in all sorts of places, it had returned to us the same little atom of nitrogen which we had owned twenty years before, and which for thousands of years had been continually going through its changes.

[Is the same true of the other constituents of plants?

Is any atom of matter ever lost?]

The same is true of any of the organic or inorganic constituents of plants. They are performing their natural offices, or are lying in the earth, or floating in the atmosphere, ready to be lent to any of their legitimate uses, sure again to be returned to their starting point.

Thus no atom of matter is ever lost. It may change its place, but it remains for ever as a part of the capital of nature.

SECTION 1 (THE PLANT) CHAPTER IV (INORGANIC MATTER) Pg 19

[What are ashes called?

How many kinds of matter are there in the ashes of plants?

Into what three classes may they be divided?

What takes place when alkalies and acids are brought together?]

We will now examine the ashes left after burning vegetable substances. This we have called inorganic matter, and it is obtained from the soil. Organic matter, although forming so large a part of the plant, we have seen to consist of four different substances. The inorganic portion, on the contrary, although forming so small a part, consists of no less than nine or ten different kinds of matter.[B] These we will consider in order. In their relations to agriculture they may be divided into three classes--alkalies, acids, and neutrals.[C]

[Is the character of a compound the same as that of its constituents?

Give an instance of this.

Do neutrals combine with other substances?

Name the four alkalies found in the ashes of plants.]

Alkalies and acids are of opposite properties, and when brought together they unite and neutralize each other, forming compounds which are neither alkaline nor acid in their character. Thus, carbonic acid (a gas,) unites with lime--a burning, caustic substance--and forms marble, which is a hard tasteless stone. 

SECTION 1 (THE PLANT) CHAPTER IV (INORGANIC MATTER) Pg 20

 

Alkalies and acids are characterized by their desire to unite with each other, and the compounds thus formed have many and various properties, so that the characters of the constituents give no indication of the character of the compound. For instance, lime causes the gases of animal manure to escape, while sulphate of lime (a compound of sulphuric acid and lime) produces an opposite effect, and prevents their escape.

The substances coming under the signification of neutrals, are less affected by the laws of combination, still they often combine feebly with other substances, and some of the resultant compounds are of great importance to agriculture.

ALKALIES.

The alkalies which are found in the ashes of plants are four in number; they are potash, soda, lime and magnesia.

POTASH.

[How may we obtain potash from ashes?

What are some of its agricultural uses?]

When we pour water over wood ashes it dissolves the potash which they contain, and carries it through in solution. This solution is called ley, and if it be boiled to dryness it leaves a solid substance from which pure potash may be made. Potash left exposed to the air absorbs carbonic acid and becomes carbonate of potash, or pearlash; if another atom of carbonic acid be added, it becomes super-carbonate of potash, or salæratus. Potash has many uses in agriculture.

SECTION 1 (THE PLANT) CHAPTER IV (INORGANIC MATTER) Pg 21

 

It forms a constituent of nearly all plants. It unites with silica (a neutral), and forms a compound which water can dissolve and carry into the roots of plants; thus supplying them with an ingredient which gives them much of their strength.[D] It is a strong agent in the decomposition of vegetable matter, and is thus of much importance in preparing manures. It roughens the smooth round particles of sandy soils, and prevents their compacting, as they are often liable to do. It is also of use in killing certain kinds of insects, and, when artificially applied, in smoothing the bark of fruit trees.

The source from which this and the other inorganic matters required are to be obtained, will be fully considered in the section on manures.

SODA.

[Where is soda found most largely?

What is Glauber's salts?

What is washing soda?

What are some of the uses of lime?]

Soda, one of the alkalies contained in the ashes of plants, is very much the same as potash in its agricultural character.

SECTION 1 (THE PLANT) CHAPTER IV (INORGANIC MATTER) Pg 22

 

Its uses are the same as those of potash--before enumerated. Soda exists very largely in nature, as it forms an important part of common salt, whether in the ocean or in those inland deposits known as rock salt. When combined with sulphuric acid it forms sulphate of soda or Glauber's salts. In combination with carbonic acid, as carbonate of soda, it forms the common washing soda of the shops. It is often necessary to render soils fertile.

LIME.

Lime is in many ways important in agriculture:

It is a constituent of plants and animals. It assists in the decomposition of vegetable matter in the soil. It corrects the acidity[E] of sour soils. As chloride or sulphate of lime it is a good absorbent of fertilizing gases.

[How is caustic lime made?

How much carbonic acid is thus liberated?

How does man resemble Sinbad the sailor?]

In nature it usually exists in the form of carbonate of lime: that is, as marble, limestone, and chalk--these all being of the same composition. In manufacturing caustic (or quick) lime, it is customary to burn the carbonate of lime in a kiln; by this means the carbonic acid is thrown off into the atmosphere and the lime remains in a pure or caustic state.

SECTION 1 (THE PLANT) CHAPTER IV (INORGANIC MATTER) Pg 23

 

A French chemist states that every cubic yard of limestone that is burned, throws off ten thousand cubic yards of carbonic acid, which may be used by plants. This reminds us of the story of Sinbad the sailor, where we read of the immense genie who came out of a very small box by the sea-shore, much to the surprise of Sinbad, who could not believe his eyes, until the genie changed himself into a cloud of smoke and went into the box again. Sinbad fastened the lid, and the genie must have remained there until the box was destroyed.

Now man is very much like Sinbad, he lets the carbonic acid out from the limestone (when it expands and becomes a gas); and then he raises a crop, the leaves of which drink it in and pack the carbon away in a very small compass as vegetable matter. Here it must remain until the