Professor Johnson says--"Soils are barren either from the presence of a noxious principle or the absence of a necessary element. It is therefore highly important to be able to distinguish between the two cases. "The art of culture is almost entirely a chemical art. Its processes are explained on chemical principals in part, but partly on mechanical and natural ones. "All forms of matter may be divided into one of the two great groups--organic or inorganic matter." In Peruvian guano, both these substances exist in a better and cheaper form than can be obtained from any other source. The editor of the Genesee farmer, whose scientific information none can dispute, strongly corroborates this opinion. In a late number he says--If we admit that phosphate of lime is a necessary ingredient in a special manure for wheat--Peruvian guano would at present be much the cheapest source of it; for, in addition to the 16 per cent. of ammonia, it contains 20 per cent. of phosphate of lime in first-rate condition for assimilation by the plant, as well as other fertilizing ingredients of minor importance. As a manure for wheat, therefore, we greatly prefer good Peruvian guano, even to the _improved_ superphosphate of lime. _Difference in favor of Guano over Bone dust._--Robert Monteith, England, dressed oat ground with 276 lbs. guano per acre, cost 31 shillings, produce 59 bushels, value L7 7s 6d. Same quality of land with 10 bushels bone dust, cost 23 shillings and fourpence, produced 43 bushels value L5 7s 6d, which gives a balance in favor of guano of L1 12s 4d, or about $7 50 per acre. _Difference in favor of Guano over Manure._--The Yorkshire Agricultural Society of England, instituted a series of experiments several years ago for the purpose of working out practical facts in relation to guano, through a series of crops, upon different soils, by different persons, upon whose report the utmost reliance might be placed, so as to determine the value, or advantage to British farmers, who might use this extraordinary fertilizer. This report has just been published, and the following is a synopsis of the results. The experiments were arranged under the following heads-- 1. To show the natural produce of the land, one part was to have no manure whatever. 2. Was to have twelve tons per acre of farm-yard dung. 3. Was to have six tons of dung, and one cwt. each of guano and dissolved coprolites; and 4. Was to have two cwt. of guano and two cwt. of the coprolites. Other substances might be tried as additions, but these were to be the standard experiments. Mr. Cholmeley's turnips, grown on a loamy soil had the heaviest crop on No. 3, the dung, coprolite, and guano, beating the farm-yard manure by some 5-3/4 tons per acre. Mr. Johnson's experiments were tried with various manures singly; and his Peruvian guano gave the greatest weight of the class of substances tried; but 10 cubic yards of farm-yard manure had previously been applied to the whole land.