1864.] CHEMISTRY OF MANURES. 115 



prising the development, under its influence, of the modern manu- 

 facturing system, with its centralized swarms of population, — 

 leading, on the one hand, to increased demand for food, and to the 

 consequent proclamation of Free trade, — leading also, on the other 

 hand, to reiterated invasion of Asiatic pestilence, and to the conse- 

 quent abandonment of the cesspool-system, in favor of certain 

 tubular arrangements, designed for the continuous removal and 

 utilization of the manurial waters, and now in midway course of 

 organization. Wholesome controversy, the mother of experiment 

 enlightens, while it retards this revolution ; and if, meanwhile, as 

 Liebig alleges, England " sucks, vampire-like, the blood of Europe," 

 it is because she herself (in this sense) bleeds from a thousand 

 wounds. As the closure of these, now her most ardent desire 

 shall be progressively accomplished, so, in like proportion, will she 

 be absolved from further need of the sanguinary supplies, for which 

 she now pays so dear. To drop metaphor, — as the new circulatino* 

 mechanism for the utilization of sewage-manure shall be progres- 

 sively worked out and realized in England, so, in like degree will 

 her importations of manure fall oflf; till at last, when her manu- 

 rial circulation shall be complete, the course of the manure-trade 

 may be reversed, and England may be in a condition to send back 

 to the continents which supply her with food, the fertilizing ele- 

 ments therein contained, or their equivalent. 



In some degree, no doubt, the development of the human race 

 accelerated as it assuredly will be by more abundant food-supplies, 

 may tend to prevent these manurial economies, by the absorption 

 in incieasing quantities, of what may be termed man's floatino- 

 capital of phosphates — to wit, those held in human skeletons and 

 blood. But large reserves of these, and of all other fertilizing mate- 

 rials, are fortunately open to our exploitation, in the as yet unap- 

 propriated domains of nature, — the ocean, the atmosphere, and the 

 underlying strata of the earth. To these mineral sources the 

 manufacturer of manures, guided in this respect by the general 

 course of modern industrial history, will doubtless have recourse in 

 an increasing degree. By aid of the steam-engine, as already ex- 

 plained, we are enabled to draw from the air, and to fix in the 

 rapidly and economically comminuted soil, increased supplies of 

 volatile plant-food. The same system will assist to open up, for 

 use (not waste), the phosphatic and alkaline reserves of the soil. 

 To the increasing substitution of fossil for recent bones, as raw 



