122 
‘riods of hiftory, falt was regarded as de- 
ftructive of vegetation, and fuppofed to be 
particularly injurious to land. . The Bi- 
fhop of Landaff -gives feveral ingenious 
conjectures as to the caufe of this preju- 
dice. The experience of later times has 
not only proved to us that this opinion 
was founded on error; but it isnow well 
afcertained that, when properly managed, 
fale proves a moft excellent, if not our 
bei, manure. Before the great increafe of 
the duties on falt, the Satie se of it 
were allowed to difpofe of their. refufe- 
fait; a duty of four-pence per bufhel only 
being impoled upon it. This refufe-falt, 
or, as it is called by the falt. boilers, the 
clearings of the brine, 1s formed by a fepara- 
tion and depofition of a certain portion of 
the earthy conténts of the brine, which 
takes place on the application of heat. 
As the colour and purity of the falt made 
in the fubfequent part of the proceis, and 
kept for fale, would be affected by this 
earthy feparation remaining mixed with ir, 
“3t is drawn or cleared out of the pans 
ie to the amount of feveral bufhels 
at each boiling. On analyfing thele clear- 
ings, they are found to confilt of dime and 
fulpkat of lime mixed in. various propor- 
tions with the common falt, which 
cryitallizes during the time this depofit 
is making. The eficacy of thefe two 
earthy fubtances as a manure has been 
Jong well known; and.there feems every 
reafon to believe, that they are rendered 
abundantly more ufeful by the addition of 
the falt. So fenfible were the farmers of 
the value of this refufe-falt as a manure, 
that at Northwich alone the quantity of 
it purchafed in one year, previous to the 
Jate increafe of the duties, amounted to 
fome thoufand tons. It was a frequent 
practice with the falt-boilers, when the 
quantity of refufe-falt was infuffcient to 
fupply the demand, te mix‘up a portion 
of foot with ordinary falt, and then difpofe 
of it inftead of refufe-falt fcr a manure. 
When the duties upon falt were {till more 
increafed, the difpofai of this refule falt 
was prohibited, and the country has been 
fince, in great meafure, deprived of the 
benefit it derived from its ufe. No refufe 
or Mae a falt, except that which after 
repeated ufing is fo fouled by the -fth- 
curers as te be unfit again to be applied 
to the curing of fith, is now permitred to 
be fo) dy without payment of the fame duty 
with the purer falt (a duty amounting 
toa prohibition fo far as its ufe as an ob 
jet of agriculture is confidered) ; and it 
has of late years been thrown ipto the 
Objfervations on the Repeal of the Duties upon Salt. 
_[March }, 
river. Thefe eure idmees have prevented 
a practical knowledge being obtained of 
the degree of benefit which might be de- 
rived from the application of this refufe- 
falt, and ftill more of the purer falt, to 
agricultural purpofes. Independent, how- 
ever, of the evidence we have of the great 
advantages derived from it as a manure, 
while the moderate duty impofed upon it 
ftill permitted its ule; we have very many 
more recent inftances of its great efficacy 
in promoting vegetation. ‘The farmers 
regretted exceedingly the lofs of fuch a 
valuable and cheap fource of emolument ; 
and it is well known that, in the neigh 
bourhood of falt-works, in order to ob- 
tain it, it has been a frequent practice 
with ‘them to procure tle connivance of 
the falt-ofhicers, notwithftanding the heavy 
penalties they fubjedted themfelves to, and 
to carry away a good deal of refufe falt to 
their lands. The effect of this upon ve- 
getation has been at leaft equal to that 
of any manure which has ever been ufed. 
An intelligent farmer, whofe veracity may’ 
be depended on, ftates, that five years ago 
he mixed up a compoft of this refufe falt 
with the earth taken-out of water-furrows; 
and at the fame time, fome lime with a 
portion of the fame earth. They were 
each laid on different parts of the fame 
field. That part of the field which had 
the lime-compoft Jaid upon it, vegetated © 
ftrongly; but it bore no comparifon to 
the health and vigour of the vegetation of 
the other portion of the field, which had 
‘the compoft with falt laid upon it; and 
notwithftanding the time which has 
elapfed, he can ftill trace, by the quantity 
_of grals thrown up, the extent to which 
the {alt-compoft had-been fpread. 
Having had fuch frong proof of its 
good effect, he was induced to ‘try ano- 
ther experiment with the falt. He laft 
{pring ftrewed a portion of land pretty 
thickly over with it, without any admix- 
ture of earth: the confequence has: been,’ 
that he has not only not received the ex- 
pected advantage, but vegetation lnas been 
deftroyed, and the land is, for the present, 
almoft bare. This is only a farther proof 
of a well-known faét, that ina finall quan 
tity, or when mixed into a compoft, falt 
is an excellent promoter of vegetation— 
in a large quantity it tends for a time to 
check it. Contradiétory as this might at 
firt appear, itis perfectly confittent with 
what is obferved in the ufe of many other 
manures. Lime, dung, and other animal 
fubfiances, which, whatever is’ the ra- 
tignale of their operation, ferve, in fmall 
Be th a 
