J 836.] 



FARMERS' REGISTER. 



75 



posed of it, when c^inbhed with sand; and it 

 serves as? a manure, which is the only view on which 

 we now have to regard il. When used forthe pur- 

 pose of" airricuUure, it is formed iiy cxposinij the 

 siihslances we have mentioned to a certain de- 

 cree of Jieat in tiie furnace, or i<ihi, of the hme- 

 burner. When tliis has been continued lor a sulli- 

 cient ienjjth of time, their weiijht becomes consi- 

 derably diminished, though they retain their fi)r- 

 mershape and bulk; and either limestone or chalk, 

 when thus reduced, is in most places known by 

 the name either of lime-shells, or shell-lime or 

 simply, shells. In this state it is called quick- 

 lime: the materials of which it is thus com- 

 posed possess hardly any active property, but 

 when burned, it then becomes caustic to the 

 tongue, and effects the speedy decomposition of 

 most vegetable and animal bodies. When ap- 

 plied in this form — cither in the way of compost, 

 or spread over the soil by itself^ — it is so far from 

 affording nutiiment to anything that may be there 

 growing, that, were its effects to be long continued, 

 it would consume it. But if water be thrown up- 

 on it, a great degree of heat is in a short time ge- 

 nerated; the burnt shells begin to crack and burst 

 asunder; and the mass graduallj- crumbles down, or 

 fiills. as it is more commonly said, into a fine pow- 

 der, which becomes white, of whatever color if may 

 have been before it was calcined. Or when it has 

 been exposed for ashort time to the influence of the 

 atmosphere, it is also found to lose this caustic 

 power, and it is thus reconverted into a substance 

 of the same mild nature as that fi'om which it was 

 obtained — in all its properties exactly resembling 

 chalk*. 



This operation is called slacking, or slaking; and 

 lime, when deprived of its scorching quality, is 

 termed slaked-lime, or, in the language of che- 

 mists, effete. Instead of waterinir it in heaps, the 

 practice which generally prevails is to lay the 

 shells upon a fallow, in small hillocks of about a 

 bushel and a half each, either thrown up around 

 the circumference of each heap, or covered up im- 

 mediately with some fi'csh soil made very fine, 

 which, when laid on moderately thick, should be 

 clapped close down with the back of the spade, so 

 as to exclude the admission of either air or rain. 

 In this state it may remain for a kw days, care be- 

 ing taken during that time to keep every part of 

 the heaps tight and sound, when it will be found 

 that the moisture of the earth will have complete- 

 ly slaked it. Although it may be thought that this 

 covering of the lime is unnecessarj', it yet has this 

 use — that without it the rain would form crusts 

 over the heaps, which would not only prevent the 

 moisture from penetratingregularlj' through them, 

 but would also hinder th;Mn ifrom bcino; pulverized 

 without considerable difficulty. It will then be fit 

 for use: and when spread over the field, it should 

 be immediately ploughed in with a shallow fur- 

 row, and well stirred with the harrows in every 

 direction. Upon an 18-feet ridge these heaps will 

 be the same distance, or 6 yards, asunder, ft-om 

 centre to centre, if about 200 bushels be laid on 

 per acre; and so on when other quantities arc ap- 



* See Hornby on Lime, p. 10; Dr. Anderson's Es- 

 says ralatin^ to Agriculture, vol. i. E^say vi.; and Sir 

 Humphry Davy, Lect. vii. When moistened with sea- 

 water, lime yields more alkali (soda) than when treat- 

 ed with common water; and is said to have been used 

 in some cases with more benefit as manure — Ibid., p. 

 298. 



plied. Instead of slaking the lime in this manner, 

 it lias however been recommended to lay it down 

 in a long heap, or mound, on one side of the field 

 on which it is to be applied. 'Two laborers are 

 then employed to turn the mound, and a third wa- 

 ters it. When the whole has been thus gone 

 over, it is allowed to lie flir four or five days, after 

 which it is again turned, and if any part of the 

 lime should be found to be still unslaked, more wa- 

 ter is added*. 



From this it will be perceived, that one chief 

 cause which renders the burning of lime necessa- 

 ry, arises li-oui the extreme difficulty of obtaining 

 the powder without the process of grinding; but 

 by being thus more finely divided, it can also be 

 more evenly difTused over the soil, with which, 

 therefore, it becomes more evenly mixed, and more 

 prompt in its effects upon the land; and when laid 

 upon it in its hot state, it not only occasions the 

 destruction of weeds, but powerfully stimulateg 

 the action of manure. An idea, indeed, general- 

 ly prevails, in consequence of burning being the 

 mode usually resorted to in the employment of 

 lime, that calcination is necessary to render it fit 

 for use as manure; but this, as we have already re- 

 marked, is a mere mistake. 



One very strong reason for applying it instantly 

 is, that, if spread immediately after being turned, 

 and while yet in a powdery and caustic state, a 

 smaller quantity may suffice to cover the whole 

 surface of the ground, and to come into contact 

 with more minute particles of the soil; whereas, 

 if suffered to lie for any length of time exposed to 

 the atmosphere, it imbibes so much moisture, that 

 it runs into clods, and can never again be so equal- 

 ly divided into small parts; wherefore a much lar- 

 ger quantity is required to produce the same im- 

 mediate effect. It is in this state, also, that it acts 

 the most powerfully upon all organic matter which 

 may be already lying undecomposed within the 

 soil — insects, the fibres and roots of obnoxious 

 plants, and the seeds of weeds — wh.ich it dissolves 

 and transforms into moidd. It is also more effica- 

 cious than effete lime in its influence upon what is 

 called sour land; Uiouo'h simple challc, if applied 

 in large quantities, will correct the evil. Neither 

 is it improbable that, during its process of slaking, 

 the heat which it generates by the absorption of 

 moisture causes it to swell in a manner which the 

 tenacitj' of the soil cannot resist: thus producing 

 fermentation, it not only eventually makes the 

 land meliow, but renders matter which was com- 

 paratively inert, nutritive, and is probably more 

 beneficial to land containing much woody fibre, or 

 animal fibrous matter, than any calcareous sub- 

 stance in its natural statef. If", therefore, quick- 

 lime really possesses superior qualities as a ma- 



* Library of Useful Knowledge: Farmer's Series, No. 

 IS, — Report of a Farm in Ross-shire. Malcolm's Sur- 

 vey of Surrey, Kent, and Sussex, vol. ii. p. 46; Pa- 

 pers cf the Bath Society, vol. ii. art. xxviii. 



t In its first effect, burnt lime decomposes animal mat- 

 ter and seems to accelerate its progress to a capacity 

 of affording nutriment to vegetables: gradually, liowe- 

 vor, the lime is neutralized by carbonic acid, and con- 

 verted into a substance analogous to clialk; but in this 

 case it more perfectly mixes with the otfier ingredients 

 of the soil, and is more pervadingly diftused, more fine- 

 ly divided, than mere chalk artificially applied. Sir 

 Humphry Davy, Elem.of Agric, Chcm., lect. \M. 



