"Still worse," Percy replied. "The calcium is commonly reported in terms of lime, or, as you would say, quick lime; and vet the soil may be an acid soil, like yours, and contain no lime whatever, neither as quick lime nor limestone. I have seen an analysis reporting half a per cent. of calcium oxid, which would make five tons of quick lime in the plowed soil of an acre; whereas the soil not only contained no lime whatever, but was so acid that it needed five tons of ground limestone per acre to correct the acidity. "The trouble is that when the chemist found calcium in the soil existing in the form of acid silicate, or calcium hydrogen silicate, he reported calcium oxid, or lime, in his analytical statement, assuming apparently that the farmer would understand that the analytical statement did not mean what it said." "But some soils do contain lime, do they not?" "Some soils contain limestone," replied Percy, "and the analysis of such a soil should report the amount of limestone, or calcium carbonate, based upon the actual determination of carbonate carbon or carbon dioxid, which is a true measure of the basic property of the soil, even though the limestone may be somewhat magnesian in character." For a set of soil samples. Percy collected soil from three different strata. The first sample represented the surface stratum from the top to six and two-third inches; the second sample represented the subsurface stratum from six and two-thirds to twenty inches; and the third sample represented the subsoil from twenty to forty inches, each sample being a composite of about twenty borings. In collecting these the hole was bored to six and two-third inches and somewhat enlarged by scraping up and down with the auger, all of the soil being put into a numbered bag. Then, the hole was extended and the subsurface boring removed without touching the surface soil. This boring to a depth of twenty inches was put into a second bag. The hole was then enlarged to the twenty-inch depth but the additional soil removed was discarded as a mixture of the surface and subsurface strata. Finally the hole was extended to the forty-inch depth and the subsoil from one groove of the auger was put into a third bag. In this manner about an equal quantity of soil was bagged from each stratum; and twenty such borings taken with an auger about one inch in diameter make a sufficient quantity to furnish to the chemist.