1836.] 



FARIVIERS' REGISTER, 



99 



as the Anglo-Norman; and unable to acconmin- 

 iate tlicinselvcs to new circumstances, the Dutch 

 ecttlers ol" rocky and rugLnni districts fell behind 

 the New England yeomanry in agricultural 



Bliill. 



We have called the use of lime a secret: it was 

 not only so to the practical farmer, but to the man 

 ot" science; lor even the researches of Davy, who 

 was well aware of its imporlance, have not com- 

 pleted the theory of its action. It is, therefore, 

 ■with no small pride, that wc can refer to a coun- 

 tryman of our own, as having hnishod v\-hat the 

 most acute researches of European chemists had 

 left unaccomplished. This credit is due to Mr. 

 Ruffin, and with him as a guide, and with some 

 little aid from the article of which he is the trans- 

 lator, we shall endeavor to exhibit, in a succinct 

 form, the theory of calcareous manures. 



In order to make this complete, we shall be 

 compelled to stale facts, which to the majority of 

 the readers ot this lournal will appear trite and 

 hacknicd. As our main object, however, is to call 

 to this subject the attentinn of mtelligcnt farmers, 

 who may not recollect familiarly the elements of 

 science, our more learned readers must pardon us, 

 if we devote a lew lines to matters in which they 

 need no instruction. 



Pure lime is so rarely found in nature, that it 

 may be stated as a general rule, that it can be ob- 

 lained only artificial!}^, in the process of calcina- 

 tion, as practiced in preparing limestones for ma- 

 king mortar. Thus obtained, litne retains the ori- 

 ginal figure of the stone horn which it is manufac- 

 tured, is acrid and caustic, soluble in small propor- 

 tion in water, and possesses alkaline properties, 

 that is to say, it is capable of neutralizing acids, 

 and forming with them substances of the class to 

 which chemists give the name of salts. Of these 

 salts, those most important to the agricullurist are, 

 the carbonate, which forms the principal part of 

 common hmestones, chalk, and the shells of tes- 

 taceous fish; sulphate of lime, which in combina- 

 tion with water constitutes gypsum or plaster of 

 Paris; and phosphate of Ijme, which is the basis 

 of the bones of animals, and has been found in 

 the ashes of plants. 



When exposed to air, lime attracts carbonic 

 acid, and jvasses back to the state whence it was 

 reduced by fire, but loses its figure and fills slowly 

 to powder. When water is thrown on lime, it un- 

 dergoes the process called slaking, and falls rapid- 

 ly to powder, producing a hydrate, which is a 

 combination with water. This powder, when ex- 

 posed to the air, also rapidly passes into carbonate 

 of lime. Both lime and its combination with wa- 

 ter promote the decomposition of animal and ve- 

 getable substances, and absorb the gases which 

 are generated by their putrefaction. The latter 

 property is also possessed by the carbonate of 

 lime, when in a state of fine powder, or even 

 when it merely exposes a large surface to their ac- 

 tion, and although rarely mentioned by chemists, 

 and in itself purely mechanical, is of the most fa- 

 nuliar character, being habitually called into use 

 in our domestic economv, to correct offensive efBu- 

 via, and absorb the miasmata which produce dis- 

 ease. 



The two other earths, as usnall}' foinul in soils, 

 (silica the base of flint and sand, and alnmina, the 

 base of clay,) appear to possess this mechaifical 

 property, either not at all or in a very inferior de- 

 gree. 



I Lime, when mixed with these earths, gives 

 j them this property, and at the same time modifies 

 their characters in a most remarkable manner. 

 Silica, which has no attraction for moisture, ia 

 rendered retentive of water by lime; and clay, 

 which forms, with abundance of water, a plastic 

 paste, and hardens, on partial drying, into a tough 

 clod, loses its plasticity and is rendered friable. 



Lime in the form of carbonate, still possesses 

 these mechanical properties, and thus limestone, 

 or shells even coarsely powdered, will absorb the 

 gases of putrescent bodies, render sand more re- 

 tentive of moisture, and convert a stiff clay into a 

 liriablc loam. 



The alteration of the mechanical clmracfer of 

 soils, is the first and most obvious effect produced 

 by lime. For this purpose, it may be applied 

 either caustic, as prepared by burning, merely pul- 

 verized fi-om chalk or limestone, or in the form of 

 disintegrated shells. The caustic form is more 

 rapid, but not more sure in its action; and fho 

 burning of limestone, when this is the object, ia 

 no more than a cheaper mode of reducing it to 

 powder, throuffh the intervention of slaking. 



When the soil contains inert vegetable matter, 

 which has ceased to undergo fermentation, caustic 

 lime v/ill promote the putrefhctive process, and 

 prepare it lor the food of plants. If the process of 

 icrmentation has stopped after the acetic stage, 

 and left the soil acid, either caustic or carbonated 

 lime will neutralize the acid; it will not only thus 

 preptire the soil to bear plants, which would not 

 otherwise grow, but, by removing the antiseptic 

 action of the acid, permit other vegetable matter 

 to undergo putrescense, and thus supply an ap- 

 propriate food for |)lantp. 



The principal part of the food of all plants is 

 derived from the gases and soluble matters fur- 

 nished by the decomposition of organic bodies. 

 These gases tend to expand and distribute them- 

 selvep through the atmosphere, with the excep- 

 tion of such as are soluble in the moisture of the 

 soil, or such as the earth may retain by mechani- 

 cal attraction. Lime and its compounds have bv 

 far the greatest powers in the last respect, and 

 thus, if a soil is calcareous, it will retain these ele- 

 ments of fertilil}', and give them out only as thev 

 are required by the wants of the vegetables that 

 grow upon it; it will be but little injured by ex- 

 posure to the air when uncovered, and will retain 

 its fertility longer. It will receive a greater quan- 

 tity of animal and vegetable manure without poi- 

 soning the plants by excess of nutriment, and the 

 effects of a given quantity will be longer seiiBible. 

 If the soil contain no carbonate of lime, this pro- 

 perty may be given artificially by manuring with 

 slaked lime, which rapidly becomes carbonated; 

 with powdered limestone or chalk; with marl in 

 the proper sense oi' the term; or with recent or fos- 

 sil shells. 



Here it might at first be imagmed, that the more, 

 free a soil is I'rotn calcareous mailer, the greater 

 the quantity of carbonate of lime which might be. 

 applied; but this is exactly the reverse of what \-t 

 pointed out by experience. We do not consider 

 that this fact is difficult of explanation. Lime can- 

 I'ot alter the mechanical texture of soils, nor izive 

 to the whole mass, the prop,erty of absorbing gases, 

 except by entering into chemical combination with 

 their other constituents. Such changes of charac- 

 ter are not only tlie universal consequence of che- 



