1860. 



NEW ENGLAND FARMER, 



41 



THE MINERAL MANURE THEORY. 



ARON LlEBiG some- 

 what astonished the 

 agricultural world, 

 several years since, 

 by the enunciation of 

 his theories in regard 

 to mineral manures. 

 By some, a few only, 

 thinking and inquir- 

 ing minds, these were 

 received not merely 

 with a cordial appro- 

 bation, but with ma- 

 ny expressions of de- 

 light. The Baron's 

 name soon became 

 familiar in all agri- 

 cultural circles, and 

 his theories were 

 adopted by many as the wonderful elixir that, like 

 the touch of Midas, was to turn all baser things 

 into gold ! They saw, prospectively, waving fields, 

 golden sheaves, and bursting granaries, with low- 

 ing herds and bleating sheep upon a thousand 

 hills, in the little snuff-box full of mineral matters 

 that were to be sprinkled upon the land ! And as 

 discussions and illustrations, which they fancied 

 were founded upon a substantial basis, increased 

 the value of these minerals in their minds, the 

 true foundation of all success in husbandry — the 

 permanent manure heaps of the farm — depreciated 

 in importance, and thus a vital bloAV was struck to 

 the cause of sound progress and success. Had it 

 not been for the influence of another element, 

 more conservative and scrutinizing, an error of 

 grave character might have been fallen into ; one 

 that would have arrested the progress of agricul- 

 ture, rather than have advanced it. 



This other class, distrustfuFand cautious, doubt- 

 ing every thing that bore an impress of ihe "pro- 

 fession" or the "shop," received these theories 

 with many discounts, and they inquired every 

 where, "What manner of doctrine is th;>5, that this 

 man teacheth ?" They did not believe that bulk 

 in manure was unimportant, though the quality 

 were concentrated in the highest drgrer>, and the 

 idea was too preposterous for consideration, that 

 potash, lime, and magnesia, with otlier matters 

 valuable or indispensable to plants, were a part of 

 the rucks Avhich they so cordially hated. They had 

 not inquired as to what materials soils are com- 

 posed of, or how much of these minerals are con- 

 stantly added to the soil by the abrasion or disin- 

 tegration of the rocks, or how little difficulty there 

 would be in determining the character of any soil, 

 had we only to consider the constitution of the 

 rock from Avhich it was originally derived. They 



had not looked upon this theory in its incipieat 

 stages, seen it grow up step by step, as its jjrojec- 

 tor had done, but looked upon it for the first time 

 as full grown, and launched upon the world as a 

 new and unattested doctrine. 



Thus the zealots and the doubters contested 

 every advanced point with each other, while more 

 practical and discriminating men searched for, and 

 found the Truth, between the extremes, and made 

 it subserve the good cause. So the Baron's theo- 

 ries, modified by himself and others, have awakened 

 a new interest and inquirj^ into the subject of 

 cliemistnj as connected loitli agriculture, from which 

 will certainly flow more ample rewards for labor 

 upon the soil than have heretofore been gained. 

 All men now regard chemistry in the cause of ag- 

 riculture not only with complacency, but with en- 

 tu'e confidence that it is an ally in the great work 

 indispensable to the highest success. 



If there was an error in Liebig's theory, it was 

 in giving it a too sweeping character, whereby 

 common persons got the idea that mineral manures 

 would more than supply the deficiency of vegeta- 

 ble and animal combined, and that a profitable 

 succession of crops could be obtained by the for- 

 mer alone. Whoever adopted this as a rule, soon 

 found his error in the depreciated products of his 

 fields. They must go together, — and without this 

 combination, it is improbable that remunerating 

 crops can for any length of time be harvested 

 from the same soil. 



In his recent "Letters on Modern Agriculture," 

 Liebig touches the point upon which rests all our 

 success in farming. With each crop, each plant, 

 or portion of a plant, he says, taken away from a 

 field, the soil loses a portion of the conditions of 

 its fertility ; that is, it loses the power of again 

 producing this crop, plant, or portion of a plant, 

 after the expiration of a number of years of culti- 

 vation. A thousand grains of corn require from 

 the soil a thousand times as much phosphoric acid 

 as one grain ; and a thousand strav/s a thousand 

 times as much silicic acid as one straw ; if, there- 

 fore, there is a deficiency of a thousandth part of 

 the phosphoric or silicic acid in the soil, then the 

 thousandth grain and straw will not be formed. 

 A single straw removed from a corn-field, makes 

 this field bear one corn straw less. This must be 

 so — and this single fact, ever present with the cul- 

 tivator, should lead him to such practices as would 

 always recuperate, rather than depreciate his soils; 

 so that, at the end of a hundred years of cultiva- 

 tion, the soil is better able to produce a paying 

 crop than it was the first year it was taken in 

 hand. 



Chemists inform us that iron floats in the blood 

 that courses through our bodies, that p/^os/j/ionc 

 acid is a constituent of the brain and of the nerves, 

 that alkaline pJiosphaies and alkaline earths exkt 



