“This shows a field of corn growing on peaty swamp land, of which there are several hundred thousand acres in the swamp regions of Illinois, Indiana, and Wisconsin.  This peaty soil is extremely rich in humus and nitrogen, well supplied with phosphorus and other elements, except potassium; but in this element it is extremely deficient.  This land was drained out at large expense, and produced two or three large crops because the fresh grass roots contained some readily available potassium; but after three or four years the corn crop became a complete failure, as you see from the untreated check plot on the right; while the land on the left, where potassium was applied, produced forty-five bushels per acre the year this photograph was taken, and with heavier treatment from sixty to seventy-five bushels are produced.”

“Seventy-five bushels would be fifteen barrels of corn per acre.  How’s that, Little Wife?” asked Tom.

“It’s even more wonderful than the pot culture,” replied Mrs. Thornton; “but how much did the potassium cost, Mr. Johnston.”

“About three dollars an acre,” replied Percy; “but of course the land has almost no value if not treated; and as a matter of fact the three dollars is less than half the interest on the difference in value between this land and our ordinary corn belt land.  These peaty swamp lands are to a large extent in scattered areas, and commonly, if a farmer owns some of this kind of land, he also owns some other good land, perhaps adjoining the swamp; but this is not always the case, and was not with the man in the story I mentioned.  This man lived a few miles away and his farm was practically all of this peaty swamp land type.  He heard of this experiment field and came with his family to see it.

“As he stood looking, first at the corn on the treated and untreated land, and then at his wife and large family of children, he broke down and cried like a child.  Later he explained to the superintendent who was showing him the experiments, that he had put the best of his life into that kind of land.  ‘The land looked rich,’ said he,—­’as rich as any land I ever saw.  I bought it and drained it and built my home on a sandy knoll.  The first crops were fairly good, and we hoped for better crops; but instead they grew worse and worse.  We raised what we could on a small patch of sandy land, and kept trying to find out what we could grow on this black bogus land.  Sometimes I helped the neighbors and got a little money, but my wife and I and my older children have wasted twenty years on this land.  Poverty, poverty, always!  How was I to know that this single substance which you call potassium was all we needed to make this land productive and valuable?  Oh, if I had only known this twenty years ago, before my wife had worked like a slave,—­before my children had grown almost to manhood and womanhood, in poverty and ignorance!’”

“Why wasn’t the matter investigated sooner?” asked Miss Russell.  “Why didn’t the government find out what the land needed long before?”