No. 5. 



Lime. 



171 



plough they have ever seen, suppose it the 

 best in the world ! Let them weigh well the 

 facts above detailed ; they will perceive that 

 a saving of even more than one-half their 

 team labour is possible, by the farmer of some 

 sections of the country." 



Lime. 



Kead before the Phil. Ag. Soc, 2d Dec. 1840. 



Remarks on the Nature and use of Lime, 

 occasioned by reading an Essay on the 

 subject by Henry R. Madden, Esq., in the 

 Edinburgh Quarterly Journal of Agri- 

 culture. 



The action of lime, as a promoter of vege- 

 tation, has long been a matter of speculation ; 

 and, while most practical farmers admit its 

 utility, few have any definite ideas of its ope- 

 ration, nor can they be expected to form cor- 

 rect theories, whilst those who make the sci- 

 ence of agriculture their particular study, are 

 groping in the dark. 



One of the most skilful and intelligent 

 writers of the present day, Henry R. Madden, 

 Esq., thus treats the subject — 



" When any organic matter is mixed with 

 hot lime," says this author, "it undergoes 

 putrefaction with much greater rapidity than 

 when left to itself The exact cause of this 

 is not well known, but the immediate changes 

 which the various substances undergo, espe- 

 cially in the case of vegetable matter, have 

 been pretty accurately examined. Thus, for 

 example, it has been proved, ^ns?, that woody 

 fibre, gum, sugar, and many other vegetable 

 matters, are converted into humic acid, with 

 more or less rapidity, when kept in contact 

 with hot lime, or any other chemical sub- 

 stance which possesses strong alkaline pro- 

 perties. Secondly, that this humic acid, 

 when formed, unites with the lime, and gene- 

 rates a compound which is not very soluble 

 in water, but is easily diffused through it. 

 And, lastly, it has been proved, that a very 

 little lime is required to produce this com- 

 pound, with a large quantity of humic acid. 

 For example, 28 grains of pure lime are ca- 

 pable of combining with no less than 318^ 

 grains of this acid ; so that the lime, in this 

 compound, amounts to little more than eight 

 per cent." 



We think the distinguished correspondent 

 of the Quarterly Journal of Agriculture has, 

 partly at least, built his theory on false pre- 

 mises. His assumption, for instance, that 

 "organic matter, when mixed with hot lime, 

 undergoes putrefaction more rapidly," is as- 

 suredly incorrect. Lime, and especially hot 

 or quick lime, is an antiseptic, and one of 

 the best preservatives of organic or vegetable 

 matter that we know of Thus lime, in as 

 fresh a state as possible, and, though a hy- 



drate, it is caustic, is applied to fences, frame 

 buildings, &c., to preserve them from decay ; 

 and every housewife, who covers her hams 

 with it in summer, when most liable to putre- 

 faction, is sensible of its antiseptic powers; 

 and women who have set their ley-tubs, can 

 attest to the perfect manner in which the 

 straw is preserved, although placed in imme- 

 diate contact with the lime. The fact is, 

 that organic substances are either preserved 

 or prolonged from putrefaction by combina- 

 tion with lime, unless applied in such quan- 

 tity and manner, as to destroy or burn them 

 up; in this case, an unprofitable decomyosi' 

 tion, nol putrefaction, takes place. 



Again, Mr. Madden tells us that not only 

 lime, but any other chemical substance pos- 

 sessing strong alkaline properties, converts 

 vegetable matter, more or less rapidly, into 

 humic acid. Now, chemically speaking — 

 and he treats the subject as a chemist — all 

 alkaline substances are preservatives, and 

 have been used, time out of mind, to prevent 

 decay or putrefaction. 



But, contending, as we have done, that his 

 reasoning is not scientific or consistent with 

 facts, we agree with the conclusion to which 

 he arrives, namely, that a very little lime, 

 when combined with decomposed or putres- 

 cent matter, termed humic acid, forms a com- 

 pound called humate of lime, which is not 

 very soluble, and in this the great advantage 

 lies. Substances of rapid solubility are too 

 transitory for permanent manures, and proba- 

 bly, one of the greatest benefits of lime is its 

 prevention of the too rapid decay and waste 

 of vegetable matter, but by a slow and gra- 

 dual intermingling and combination of lime, 

 carbon, magnesia, &c., and their gradual so- 

 lution — which, though slow, is progressive 

 and certain — the food of plants is furnished 

 in the exact manner that nature requires to 

 effect a vigorous growth. 



Were the alkaline earths wanting, a part 

 of the proper food of vegetables would be ab- 

 sent, and, although the soil might contain a 

 sufBcient per centage of vegetable manure, 

 a rapid and healthy production should not be 

 anticipated. It may be answered, that plenty 

 of vegetable and animal manure will produce 

 good crops without liming; this we admit, 

 but not without lime, for, be it remembered, 

 most vegetable substances, and particularly 

 cereal grains and straw, the components of 

 barn-yard manure, contain lime, magnesia, 

 potash, &c., which, for a time, sustain vege- 

 tation. When these are exhausted, the por- 

 tion of vegetable or animal matter remaining, 

 lies dormant, and is only brought into acti- 

 vity by the addition of alkalies, which, com- 

 bining with it, form the necessary pabulum 

 of vegetation. 

 This view of the question fully explains 



