As stated, things have been greatly simplified. Chemists, by thousands of experiments, have found in all sixty-five single separate things they call elements. Seventeen of these elements are in the soil. Out of these seventeen the farmer is obliged to provide only four, as the remaining thirteen, with favorable weather and proper tillage of the soil, will take care of themselves. The four to be provided are nitrogen, potassium, phosphorus and calcium. The first three elements are the most important, as they are plant foods or fertilizers. The last, calcium, or lime, is a stimulant, and serves in the capacity of neutralizing the acids of the soil. Lime is abundant in many soils and in such soils is not needed; but where it is needed it is needed badly and should be supplied. Nitrogen, potassium and phosphorus are the plant foods that are yearly consumed in various quantities by various crops, which are taken away and sold or otherwise disposed of. They are foods absolutely necessary to plant life, and if taken away and never returned, the soil is as certain to become poor and exhausted as the sun is to set in the west. This is the sum and substance of the whole matter. What you take from the soil, you have to replace or suffer loss. Your soil may need one, two, three or all four of the elements. What it requires can be found out by experiment, as will be shown further on. These elements as everyone must know, can be easily obtained at costs varying with, and depending upon, the form in which they are bought, or methods by which they are secured. The all-important thing is to study the soil and prepare it to accept and properly appropriate whatever foods are applied. No fertilizer is insurance against laziness and ignorance. It takes work and intelligence to accomplish any task. Study your soil, and you will appreciate the fact that it has a constitution like yourself, and will get worn out, and sick, and need physic just as you do. After knowing its constitution, you can prescribe and administer the physic it requires. No doctor can prescribe medicine intelligently without knowing the constitution of his patient. Naturally, though unfortunately, men of science, so far as the farmer is concerned, are quite as intricate in their explanations of the objects of nature, as are the objects themselves. Mr. Charles Bernard in his “Talks About Soils,” published by Funk & Wagnalls, New York, is the first to reduce matters to a practical plane. His explanations and experiments I therefore adopt to simplify and make clear many things which are of unquestionable importance. The soil having been formed, in the main, by the weathering away of the rocks, its foundation is either sand or clay or both combined. On account of different quantities of sand and clay being found in different soils, and to distinguish one from another, soils have been divided into six classes. These are as follows: