{ Insoluble silicious matter, { 73.84. Consisting of: { Alumina 4.14 { Lime (in a state of silicate) 2.69 Insoluble in acid { Magnesia .68 { Potash .24 { Soda .21 { Silica 65.88 ----- 99.59 ===== “The soil, it will be seen, in general character, resembles the preceding sample; it contains a good deal of potash and phosphoric acid, and may be presumed to be well suited to the growth of clover. It contains more carbonate of lime, and is somewhat lighter than the sample from the part of the field twice mown for hay, and may be termed heavy calcareous clay. “An acre of this land, 18 inches deep, weighed, when very nearly dry: Lbs. Surface, six inches 2,407,900 Next ” 2,444,200 Third ” 2,480,500 “Or in round numbers, every six inches of soil weighed per acre 2½ millions of pounds, which agrees tolerably well with the actual weight per acre of the preceding soil. “The amount of phosphoric acid and nitrogen in each six-inch layer was determined separately, as before, when the following results were obtained: In Dried Soil. First six Second Third six inches. six inches. inches. Percentage of phosphoric acid .159 .166 .140 Nitrogen .189 .134 .089 Equal to ammonia .229 .162 .108 “An acre, according to these determinations, contains in the three separate sections: First six Second Third six inches. six inches. inches. lbs. lbs. lbs. Phosphoric acid 3,975 4,150 3,500 Nitrogen 4,725 3,350 2,225 Equal to ammonia 5,725 4,050 2,700