"Well, I was only thinking," Percy continued, "that you analyze a fraction of a pound of soil in a few minutes, while the corn plant analyzes about a ton of soil by a sort of continuous process, which covers twenty-four hours every day for about one hundred and twenty days, and it takes into account every change in temperature and moisture, the aeration with any variation produced by cultivation, and also the changes brought about by the nitrifying bacteria and all other agencies that promote the decomposition of the soil and the liberation of plant food, including the action upon the insoluble phosphates and other minerals of the carbonic acid exhaled by the roots of the corn plants, the nitric acid produced by the process of nitrification, and the various acids resulting from the decay of organic matter contained in the soil." "I am very familiar with the literature of the whole subject of soil fertility," replied the Chemist, "and our theories are being accepted everywhere. I have just returned from a lecture tour extending from Florida to Michigan, and our ideas and methods are being very generally adopted, not only in this country but also in Europe." "The Chief of the Bureau very kindly permitted me to look over the maps and reports relating to the soils of Maryland and Virginia," said Percy, "but in this literature I found no data as to the amount of plant food contained in the various soil types that have been found in the surveys. May I ask if the Bureau has made any analyses to ascertain the total amounts of the different essential plant food elements contained in these different soils?" "No," the Chemist replied, "a chemical analysis gives practically no information concerning the fertility of the soil. We have made no ultimate analyses of soils, although we have used the same methods of analysis in a study of the partial composition of the soil separates, or particles of different grades, such as the sand, the silt, and the clay." "And have you also determined the percentages of sand, silt, and clay in the soils themselves?" "Oh, yes, the physical composition of the soil is a matter of very great importance, and this is always determined and reported for every soil. Did you not see that in the Reports you examined this morning?" "I think I did notice it," Percy replied, "but it is so easy for the farmer himself to tell a sandy soil from a clay soil that I did not appreciate the value of those physical analyses. "In any case, I shall be very glad to know what results were obtained from the chemical analysis of the soil separates to which you referred."