'HUSBANDRY. S (57 
Burir it into liine, be beneficially employed for the ame¬ 
lioration of land, as has been Ihown by the experiments 
of Monf. Du Hamel, and others. When thus ufed, it 
ihould be well pulverized, by fuch rhechanical means as 
can be cheaply performed j, much of the advantage to be 
derived from it probably depending upon its'being reduced 
into a confiderable degree of finenefs-, by which it may be 
more minutely blended with the foils on which it is ap¬ 
plied, and thereby aft upon and afford nutritious princi¬ 
ples more extenfively for thefupport of crops; and at the 
lame time render the heavy and more cohefive foils lighter, 
.by being more uniformly incorporated with their clayey 
and earthy materials. But as calcareous fubftances can 
never be reduced, by any fort of machinery, to the fine 
powdery ftate to which they are capable of being carried by 
means of calcination, it is probable that, when employed 
upon land, they will be lefs beneficial, in many cafes, 
than when ufed in the Hate of lime. It is on the above 
principles too, moll probably, that the fcrapings of roads, 
made with calcareous and other fubftances, are found fo 
beneficial in different inftances, a large portion of them 
being in the ftate of an extremely fine powder, from the 
attrition of the wheels of carriages, and other caufes. 
The experiments of Mr. Tennant, which have been al¬ 
ready noticed, fuggeft, that even, where magnefian liine- 
ftone is made ufe of in this ftate of reduftion, without 
being converted into lime, it may not be fo friendly to 
vegetation as that which is perfeftly calcareous, efpeci- 
ally when employed in the lame proportions ; a circutn- 
itance which may, in fome degree, account for the differ¬ 
ence which has been obferved in the utility of fuch fub¬ 
ftances as manures. Such lime-ltones as contain the 
largell proportions of argillaceous earth in their competi¬ 
tion, when employed in this- reduced ftate, will be the 
molt proper for the thin light foils; as by that means the 
Itaple of them may be increafed to the great advantage of 
the crops. In the application of this fort of material to 
land, the farmer Ihould conllantly be attentive to the 
ftate or condition to which it is reduced, as well as the 
nature of the foil, and put it on in fuch proportions as 
may be moll fuitabie to them. 
Lime-Jlone gravel , a fubftance which has been fuccefs- 
fully laid upon land in Ireland, ana which is a kind of 
Irony marl, might mod probably be equally or more be¬ 
neficial, in coniiderably lefs quantities, if the ftony lumps 
which it contains were firlt more perfeftly reduced ; for 
it has been remarked, that, where the pieces are large, a 
much greater proportioh is required, and the effefts are 
flower, than where they are fmall. 
Chalk is another material of the calcareous kind, which 
is capable of producing good effefts on land, when ap¬ 
plied in a fuitabie manner in its uncalcined ftate. From 
its having a portion of argillaceous or clayey matter 
united with it in fome cafes, it partakes of the nature of 
marl. Where it is made ufe of to the more ftiff, clayey, 
loamy, and heavy, forts-of foils, it Ihould, in moft cafes, 
be as much pulverifed and reduced as poffible before it is 
laid on, in order that it may be fpread with greater ex- 
aftnefs, and be more regularly mixed and blended with 
the ftiff and compaft materials of fuch lands; from which 
they may be rendered more capable of admitting the 
fibrous roots of vegetable-crops to fpread themfelves in 
them, and thereby take in more perfeftly the nutritious 
matters which are prefented to them. That this praftice 
is of much utility and advantage, is evident from the cir- 
cumltance of farmers, in moft of the diltrifts where chalk 
is employed as a manure, finding that it is confiderably 
more beneficial when made ufe of in the fpring,, after 
having been dug up in the autumn, and expofed to the 
froft and moillure through the following winter, and by 
that means match pulverifed and broken down, as well as 
by their carefully breaking and reducing the larger pieces. 
It would probably, however, be a Hill more advantageous 
praftice to break it down, and apply it as quickly as pof¬ 
fible, after digging it out of the pit; as by leaving it ex¬ 
pofed to the atmofphere for fome length of time, it not 
only becomes hard, but likewife lefs foluble, and there¬ 
fore lefs proper for the purpofes of manure. Hence it 
probably is, that farmers, where the chalk-hufbandry is 
praftifed, find the dreflings more efficacious when the 
chalk is dug from a confiderable depth, than where it lies 
near the furface of the ground. In the dry and light 
foils, too, it may probably be more ferviceable in this re¬ 
duced and powdery ftate, from the circumftance of its 
poffeffing more moifture, on account of a more extended 
furface being expofed to the air, and the particles of the 
foil, from which it may abforb and attraft it, and after¬ 
wards part with or afford it in a more regular and uni¬ 
form manner to the abforbent roots of the growing vege¬ 
table-crops. The obfervations of practical farmers, Ifow- 
ever, invariably fhow, that on fuch foils it is much more- 
beneficial when made ufe of in the form of compoft, ei¬ 
ther with rich peat or vegetable-earth and mould, or with 
good dung; as by this means a great defeft k in fuch kinds 
of land, the want of well-reduced vegetable matter, is re¬ 
medied, and a greater proportion of nutritious materials 
afforded for the fupport of crops. 
When this manure is employed upon the more wet 
and poachy kinds of ground, there is probably not the 
fame necefiity for its being reduced to a great degree of 
finenefs, as it may be apt, under fuoh.circumftances, to 
diffolve, and fink down too much by being fo greatly di¬ 
luted with water, while in the rounder ftate it may be 
retained nearer the furface, and thereby be capable of ab- 
lorbing and taking away the fuperabundant furface-moif- 
ture more effectually. But even in fuch foils, where the 
principal intention is the deftruftion of mofs, rufhes, and 
other coarfe plants, the growth of which depends upon a 
great degree of fuperficial wetnefs, it may be employed 
moft advantageoufly in a ftate of confiderable reduftion, 
as, from its greater readinefs to fink down, it may the 
more quickly take away from their roots The exceflive 
moifture that fupports them. It may, perhaps, neutralife 
acids too, when they exiit under certain combinations ia 
thefe foils, more readily when applied in its comminuted 
or pulverifed ftate than in the lumpy one in which it is 
commonly ufed. 
The proportion in which this fubftance is to be applied 
to the ground mull depend, in a great meafure,.upon the 
ftate of the foil, the.nature of the crop, and the purpofe 
for w’hich it is employed. In many of the fouthern 
counties it is laid on the ftiff clayey foils in large quanti¬ 
ties, as from twelve to fourteen or fifteen waggon-loads, 
of from fifteen to twenty hundred-weight each, to the 
acre ; and on the fandy foils in fome parts of Kent, at 
the rate of a hundred and fixty buftiels to the acre. 
But, as chalk cannot, by any means, be reduced to that 
ftate of powdery finenels that is the cafe with lime, and 
confequently cannot be fo equally fpread out; or fo mi¬ 
nutely blended with the loil, it is evident that much 
larger proportions of it nntft be employed to produce the 
fame effefts on the foil; perhaps feldom lefs than three or 
four times the quantity will be required. 
Where chalk muft be carried from a great diftance in 
its wet heavy ftate, it will generally be the moft econo¬ 
mical praftice to have it firft converted into lime. 
Marl is a calcareous fubftance, found under very dif¬ 
ferent forms, and in different places, and made ufe of as 
a manure with much advantage, both on the thin light 
foils; and fuch as are more heavy and compaft. It is 
diftinguifhed, from its particular appearances, into jhell, 
day , and ftone, marl. The firft is evidently of animal ori¬ 
gin, from its being compofed of teftaceous or fhelly mat¬ 
ters, in greater or lefs degrees, of attenuation, from the gra¬ 
dual decompolition which they have undergone during 
the fucceflion of ages, with a fmall portion of earthy fub¬ 
ftances mixed and blended with them. It is cordlantly 
found in fuch fituations as have been covered with water, 
from which, as the fedimer.ts or depofitions of mud or 
other earthy materials, in fuch cafes, muft have been dif¬ 
ferent. 
