Phosphoric acid soluble in water, 6 “ “ soluble in ammonium citrate, 5½ “ “ in fine bone and tankage, 5½ “ “ in fine medium bone and tankage, 4½ “ “ in medium bone and tankage, 3 “ “ in coarse bone and tankage, 2 “ “ in fine-ground fish, cottonseed meal, linseed meal, castor pomace, and wood-ashes, 5 “ “ insoluble (in ammonium citrate) in mixed fertilizers, 2 Potash as high-grade sulfate, and in mixtures free from muriate, 5 “ “ muriate, 4½ The manurial constituents contained in feed stuffs are valued as follows: Organic nitrogen, 15 Phosphoric acid, 5 Potash, 5 The organic nitrogen in superphosphates, special manures, and mixed fertilizers of a high grade is usually valued at the highest figures laid down in the trade values of fertilizing ingredients in raw materials; namely, eighteen and one-half cents per pound, it being assumed that the organic nitrogen is derived from the best sources; _viz._, animal matter, as meat, blood, bones, or other equally good forms, and not from leather, shoddy, hair, or any low-priced, inferior form of vegetable matter, unless the contrary is evident. In such materials the insoluble phosphoric acid is valued at two cents a pound. These values change as the markets vary. The scheme of valuation prepared by the Massachusetts station does not include phosphoric acid in basic slags. By many experimenters the value of the acid in this combination, tetracalcium phosphate, is fully equal to that in superphosphates soluble in water and ammonium citrate. It would perhaps be safe to assign that value to all the phosphoric acid in basic slags soluble in a five per cent citric acid solution. Untreated fine-ground phosphates, especially of the soft variety, so abundant in many parts of Florida, have also a high manurial value when applied to soils of an acid nature or rich in humus. On other soils of a sandy nature, or rich in calcium carbonate, such a fertilizer would have little value. The analyst in giving an opinion respecting the commercial value of a fertilizer, must be guided not only by the source of the material, its fineness or state of decomposition, and its general physical qualities, but also by the nature of the crop which it is to nourish and the kind of soil to which it is to be applied. GENERAL ANALYTICAL PROCESSES.