direct manure. All its other influences are indi- 

 rect, on which account it is most generally re- 

 gai'ded as a stimulant rather than a manure. I 

 am speaking, of course, of carb. of lime as it ex- 

 ists in our maris, and not the sulphate or phos- 

 phate of lime. 



Its indirect action, however, is as important as 

 it is varied. I have already said it promotes de- 

 cay by neutralizing acids. But while lime from 

 its neutralizing power promotes decay, by ar- 

 resting the infiueuce of acids and giving efficien- 

 cy to the legitimate agents which accomplish it, 

 it is a watchful guardian over theii' action, re- 

 tarding their wasteful haste, and sometimes 

 wholly preventing farther progress for a time. — 

 It expels, for instance, from decomposing sub- 

 stances, ammonia, which is the most active and 

 rapid conductor of pulretying contagion, driving 

 it into the air to descend in future showers, or, 

 if they are at hand, into other substances less ad- 

 vanced in the stages of decay. 



The ultimate result of the vegetable decompo- 

 sition thus judiciously forwarded by lime, is a 

 substance to which various names have been ap- 

 l>licd by chemists, such as "humus," " geine," 

 '• ulmin," &.C., which, so far as Agriculture is 

 concerned,^ — ^their treatment and influence on 

 the growth of vegetation, are one and the same 

 thing ; meaning, substantially, that residuum of 

 decomposition Nvhich is familiarly known to us 

 as " vesetahle mould," without a sufficiency of 

 which, in our soils, we are all awai¥ that compen- 

 sating crops cannot be made. In the progress 

 of decay the most soluble portions of this mould 

 are exhausted and assume new forms, and what 

 at last remains apparently fixed in the soil is the 

 undissolved sediment. This is said to be wholly 

 in.soliibIe in water, but when plowed up and 

 frequently exposed to the action of the air, it be- 

 comes so, sparingly. Yet, without aid from some 

 other source than the atmosphere, water will not 

 famish it to plants in sufficient quantities for 

 their vigorous growth. Now the alkalies and 

 alkaline earths (lime being the most important 

 of this last class) act directly on this insoluble 

 substance. Their presence — and it is a sintru- 

 lar but well known principle in Chemistry, that 

 mere presence is a power called* catalytic — indu- 

 ces it to absorb oxygen from the atmosphere, 

 and to produce what is called humic acid. With 

 these acids the alkalies immediately combine 

 and form salts called humates, which are .soluble 

 in water, and aftbrd nourishment to plants. — 

 Thus when lime is properly applied to land, it 

 brings into fruitful action the hitherto inert veg- 

 etable mould. 



But it must be obvious that if no additional 

 vegetable matter is given to the soil, the effect 

 of lime will be to exhaust it utterly, in a shorter 

 time than might otherwise be done by cropping. 

 Hence the saying that liming land enriches tlie 

 father but impoverishes the son. It must not be 

 forgotten, however, that the lime ha.s enriched 

 the father, by giving abundantly to his crops 

 food that would otherwise have remained dead 

 in his soil, or been eliminated by other agents, 

 through a series of years, in feeble proportions, 

 to scant, and therefore profitless crops : while, 

 if it impoverishes the son, it is because a wretch- 

 ed husbandry has taken all fropi the land, and 

 given nothing in return. The exhau.sting effect 

 of lime is mitigated, however, by another highly 

 important intennediate condition of the pirocess. 

 As the mould disappears, the proportion of lime 

 to mould of course increases, and the lime be- 

 comes excessive. When this is the case, the 



humate, which before was .=olub!e, becomes 

 wholly insoluble in water. The process of de- 

 composition then ceases for a time. And such 

 is the case very soon, wherever lime or marl, in 

 very large do.ses, is put on laud possessing but 

 little vegetable matter. It is called " marl 

 burnt," among the marlers — many instances of 

 which 1 can point out on my plantation. In 

 course of cultivation, ho\vever, the lime being 

 constantly e.xposed to the atmosphere, absorbs 

 carbonic acid, which, combining with a portion 

 of it, converts it into carbonate of lime again, 

 and thus freeing the humate, or a part of it, of 

 the excess of lime, renders it soluble once more. 

 But this is a very slow process, and unless tliere 

 are immense quantities of vegetable mould 

 which have been thus locked up by an extraor- 

 dinary and injudicious application of lime, and 

 probably even then, the proper plan is to reme- 

 dy the evil at once, by a heavy coating of vege- 

 table matter brought fresh from the woods. — 

 When this cannot be ettected, we should give 

 the land a long and ab.=olute rest, allowing every 

 particle of vegetation it produces to rot upon it, 

 and if it can be conveniently done, to plow it in. 

 The best of all methods, however, to restore the 

 land, and not alwajs thamost expensive, would 

 be to add a sufficiency of compost manure. Be- 

 sides the amount of "decayed vegetation which 

 such manure would supply, the alkalies potash 

 and soda are always generated in compost 

 heaps. These act directly on the insoluble hu 

 mate of lime, decompose it by their greater af- 

 finity lor the humic acid, and form new salts 

 which are quite soluble. 



Instead of objecting to this action of lime in 

 locking up the food of plants, and its constant 

 tendency to do so when that food is not made 

 abundant by good husbandry, we should rather 

 regard it as one of its most valuable properties. 

 The vegetable mould was dead in the soil. It 

 could not be can-ied away, but it was of little 

 value as it stood. The lime by its presence 

 persuades it to decompose in suiEcicnt quanti- 

 ties to nourish a luxurious growth of plants. So 

 soon as the mould begins to become scarce, the 

 lime confines it in its embraces and preserves it 

 from the ^sasteful influence of heat and moist- 

 ure. Yet, to the industrious farmer whose con- 

 stant furrows give access to the atmosphere, it 

 yields up what a prudent economy would dic- 

 tate, under existhig circumstances, to promote 

 the growth of vegetation. If that vegetation is 

 permitted to remain and decompose upon the 

 land, "vegetable mould," in time, becomes 

 abundant again, and the lime prepares it to fur- 

 nish ample Ibod for heavy crops once more. If 

 all the produce is taken o"tt; the lime, more pro- 

 vident than the farmer, and more generous too, 

 still preserves what remains in the soil, for the 

 exclusive use of the crop, and doles it out until 

 all is gone. 



The influence of lime upon the mineral sub 

 stances of the earth is scarcely less powerful 

 and iraportaiU to the farmer than on the vegeta- 

 ble. The chief mineral constituents of the soil 

 are, as you know, sand and clay. They are 

 u.sually resolved by agricultural chemists into 

 \yhat they call silica and alumina, which are 

 silicon and aluminum, their ultimate principles, 

 with a little oxygen absorbed from the atmo- 

 sphere. Of these two, silica is much the most 

 abundant, as well, perhaps, as most valuable. 

 After what we call clay has been deprived of 

 its sand by washmg, in which state it is usually 

 denominated pure or agricultural clay, it still 



