HUSB 
pie (late will correft acidity, deftroy ru/fies, and render 
the foil lefs retentive of raoilture. When (hells are burnt, 
they are in the Hate of.lime, and muft l?e ufed as fuch. 
Sea-fand is an excellent manure on a fummer-fallow 
for wheat; but, being repeated two or three times, lofes 
much of its good eftefls, without a chapge of tillage. 
Straw being fcarce at Yarmouth, they litter their (tables 
with fea-fand ; as the bed becomes foiled or wet, frelh 
fand is fcattered on, until the whole is in a manner fatu- 
rated with dung and urine ; the (tall is then cleared, and 
a frefh bed of fand laid in. Thus muck of a quality An¬ 
gularly excellent is produced. 
Sea-fand is much ufed by florifts in Holland, where 
they draw their parterres into ridges before winter, and 
fpread it on the tops of them. 
Clay. As farids are an improvement to clays, fo, on the 
contrary, clays are an improvement to gravelly and fandy 
lands, by making them more (olid and tenacious. Mr. 
Legrand, of Guilton-houfe, near Sandwich, has ufed clay 
with aftoni(hing fuccefs upon a foil almoft entirely fand ; 
but, it is not a lingle or (light dre(hng that will do any 
good 9 one hundred and fixty loads an acre make a won¬ 
derful improvement. 
It muft be remembered that marl and clay are often 
confounded, and that marling is frequently called clay¬ 
ing. The extent to which claying has been carried in 
the fand-diftrifts of Suffolk is very confiderable. An ex¬ 
cellent cultivator near Bury, though not on a very large 
farm, has carried 140,000 loads. But, when this clay is 
not of a good fort, that is, when it has very little clay in 
it, but is rather an imperfeft hard chalk, there are great 
doubts how far it anfwers, and in many cafes it has been 
certainly fpread to little or no profit. The ufual quantity 
is from fixty to eighty, and fometimes a hundred, loads, of 
thirty-two bufiiels, to an acre. The duration, and in¬ 
deed the whole effeft, depends much on the courfe of 
crops. If the plough be too freely ufed, and corn (own 
too often, it anfwers badly, and the effect is foon loft ; 
but with good management it lafts twenty years. In 
many cafes, a courfe of fallow and rye or light oats is 
converted to fine barley, clover, and wheat, and the pro¬ 
duce multiplied twenty fold ; but the cafes in which the 
return has been inadequate are not a few ; and on foils 
that will yield faintfoin, it is more profitable to cultivate 
that, than clay the land for corn. 
In (tiff deep clays, where manure is not to be had in 
fufficient quantities, and fuel is cheap, it may be no bad 
procefs to burn fome of the clay, which will not only 
break the cohefion of the foil and make it more eafily 
cultivated, but will alfo render it lefs retentive of moif- 
ture, and thus more friendly to vegetation. Upon thin 
foils, it is evident, any attempt at burning would be 
highly improper. Mr. Belcher found a furprifing effefit 
in°haif-baking earth, which renders dead barren earth 
immediately productive. It muft be only half-baked; for 
if fully baked, it in a great degree reverts to its priftine 
fterility. He does not mention whether it was clay or 
vegetable earth that he baked ; the nature of the latter we 
know from paring and burning, but we have not had ex¬ 
periments enough to afcertain the effefts of burning clay. 
Gypfum, or plajlcr of Paris, is calcareous earth united 
with the vitriolic acid. It does not effervefce with acids, 
and is not. without difficulty foluble in any. When 
heated a little below ignition, it undergoes a motion 
fimilar to that of ebullition, from the dilfipation of its 
aqueous parts, and falls into powder. If taken up when 
this motion ceafes, and fprinkled over with water, it foon 
concretes, and hardens by reafon of its fudden cryftalli- 
zation. It is entirely foluble in a large quantity of wa¬ 
ter, and may be compofed by faturating the vitriolic acid 
with calcareous earth. What we commonly call hardnefs 
jn water, is owing to gypfeous felenites diflolved in it. 
Gypfum has lately been extolled in feveral foreign 
publications, as a manure of the higheft value in Ger¬ 
many, and particularly in America, where, according to 
ANDRY. 571 
Mr. Chancellor Livingfton, of New York, it has pro¬ 
duced a new era in agriculture. This gentleman, after 
having continued his experiments three years, concludes, 
1. That gypfum in fmail quantities has no vifible eftefl 
on wheat or rye. a. That it is uniformly beneficial to 
Indian corn, unlefs in very rich or wet foils. 3. That it 
is beneficial to flax, on dry poor fandy land. 4. That it 
is peculiarly adapted to the ‘growth of clover on all. dry 
foils, or even on wet foils in a dry feafon. 5. That iime- 
(tone pulverized lias fimilar effefts with gypfum. 6. 
That the effects of gypfum as a manure are hardly per¬ 
ceptible in the vicinity of the fea. 
In the experiments of George Logan, efq. it appears 
that gypfum was ufifth 1 even to crops of wheat and rye. 
Tips gentleman remarks, 1. That there is no difference 
between the American gypfum and that which he had 
from Europe. 2. That it afts as an immediate manure 
to grafis, and afterwards in an equal degree to grain. 3. 
That one drefiing will continue in force feveral fucceed- 
ing crops. 
He adds, that its not producing any remarkably bene¬ 
ficial effects, when ufed as a top-dreifing to grain, may 
arife from two caufes;: firlt, from the fmail quantity made 
ufe of, which is loft in the rough ground ; and, fecondly, 
from the (hort time of its application. That it has been 
found of advantage to Indian corn ; but that it is necef- 
fary to apply it immediately to the corn as it appears 
above ground, and that in a confiderable quantity. That 
early in April is preferable to any other feafon for apply¬ 
ing it to paiture.; for, the grafs being juft (hooting at 
this feafon, the fmail particles of the gypfum are retained 
about the roots, and prevented from wafhing away. On 
((iff clay foils it will produce an increafe of vegetation, 
but not lufScient to pay the expence of the manure. 
In general it is faid to have had great effects on what 
they call their worn-out lands in America. After hav¬ 
ing broken the plafter into (mail pieces by a hammer or 
(hmping-mill, they reduce it to powder in a common 
grid-mill, and in this (fate fpread it upon the ground in 
a calm day. In mifty weather it will fpread to moll ad¬ 
vantage. The moft approved quantity for grafs is fix 
lndhels to the acre. It has been ufed in the ftate of Penn- 
fylvania ever iince the year 1778, if not fooner, and lafts> 
from feven to ten years, but its continuance very much 
depends on the nature of the foil fo which it is applied. 
By a letter to Capel Lofft, efq. it appears that gypfuin 
was come into general ufe as a manure in Pennfylvania, in 
the year 1789 ; and that the grounds within ten miles of 
New York, which were deemed old worn-out fields, have 
by the ufe of this manure heen fo recovered as to fupport 
fifty head of cattle, where in its former ftate one could 
not live. 
It is faid to have been difeovered as a manure in Eu¬ 
rope by Mr. Meyer, a clergyman of uncommon merit, in 
Franconia, in the year 1768. It has been applied with 
fignal fuccefs in Germany, Swifierland, France, See. and, 
if it has not met wi^h the fame fuccefs in England, it 
mull probably be, becaufe the calcareous principle pre¬ 
vails here fo generally. Sir Richard Sutton and others, 
who have tried gypfum here, have not been able to trace 
any effects from it. Mr. Pro< 5 lor Anderdon,, of Henlade, 
Somerfetfhire, concludes from fome experiments, that on 
many plants, or in many foils, gypfum-powder will have 
no effect ; but that it has fome effefl on old clover in a 
loamy foil; and that a greater effefl may reafonably be 
expefted from it, when applied to younger plants of the 
fame fort or nature. This agrees with the American ac¬ 
counts, clover there being the crop more benefited by 
gypfum than any other. Calcareous earth indeed is ge¬ 
nerally acknowledged to be favourable to the growth of 
clover; but the addition of the vitriolic acid, a, fufpe&qd 
poifon in agriculture, would naturally have induced the 
agricultural chemift to have rejefted gypfum as a manure. 
According to Kirwan, the rationale of its effects may 
be deduced from its extraordinary feptic power, for it is 
found 
