£26 H U S B A 
they may, by their nearer approach to each other, com¬ 
bine fo as to produce nitrous acid ; or the oxygen, in its 
fluid ftate, not in its aerial one, may more readily unite 
with carbon, and thus conftitute a fluid, not aa aerial 
carbonic acid, which is fuppofed to be of great utility in 
promoting the growth of plants. And further, that if 
any procefs of the putrefactive kind be going on where 
atmolpheric air is in this way confined in the interftices 
of the foil, and by the deprivation of its heat is convert¬ 
ed from a gas to a fluid, the azot may combine with the 
hydrogen of the decompofmg water, or contribute to de- 
compofe it, and in this manner form volatile alkali, which, 
like nitrous acid, may,, either during the procefs of its 
formation or. after that has been completed, be of very 
material utility in promoting vegetation, while at the fame 
time the oxygen afforded by the decompofing water may, 
like that of the atmofphere, contribute to the production 
of the carbonic, nitrous, or phofphoric, acids ; and in this 
way render carbon, phofphorus, and the bafis of nitre, 
capable of being taken up by the abforbent roots of grow- 
Tng plants. From the great diminution of bulk that has 
been found fro pi experiment to take place where atmofphe- 
ricairis confined in contaCt with water, it is conceived that 
there may be a decompofition of both the water and the 
air, and a production of both ammonia and nitrous acid, 
which’ are known to be beneficial in promoting the growth 
of plants. It is conceived that, in thefe different views, 
the praCtice of fallowing may in various inftances be 
highly beneficial, notwithstanding the objections that have 
been brought againlt'it by fome writers on hufbandry; 
but at the fame time it mult be admitted that it will be 
much more advantageous and ufeful in fome foils than in 
others. On the lighter kinds of land, where full and 
luxuriant crops of different forts of plants, as turnips, 
potatoes, &c. may be grown, that produce a dole thick 
foliage, and which, as has been fliown by experiment, af¬ 
ford under fuch circumftances much carbonic acid, which, 
from its being greatly heavier than the common air of 
the atmofphere, muft fall upon, and be mixed with, the 
foil in fuch ftagnated fituations, and thus, together with 
the more conftant moifture that muft be prelent in fuch 
cafes, promote the folution and decay of various vegeta-. 
ble matters, and continually add carbonaceous and other 
materials, fo as to greatly improve the foils; it can but 
feldom be necelfary. Befides, as in thefe foils, b}/- theufe 
of the drill/and repeated hand or lrorfe hoeing during the 
growth of the crops, the ground may be kept perfectly 
dean from weeds, and in a fine mellow or powdery ftate, 
without the danger of being injured by too much evapo¬ 
ration and expofure in the way of fallowing ; and likewife 
in foils of the fame nature, that are rich from the fre¬ 
quent applications of manure, and in which the proceffes 
by which the dilferent nutritious fubftances that have 
been defcribed are formed and prepared, are properly go¬ 
ing on, it muft be improper to expofe their furfaces too 
frequently to the influence of the air, fun, and rain, by 
which the little ftrengtli of fuch light lands would be too 
much weakened. 
But in all the wet-bottomed, ftifF, adhefive, and clayey, 
forts of foil, which conftitute a large proportion or the lands 
of the kingdom, where, from the cloienefs of their textures 
and the great tenacity of their particles, but a very flight, 
or indeed fcarcely any, degree of pulverization has been 
effe&ed, the practice of fummer-fallowing muft be highly 
advantageous, not only by the mechanical alterations that 
take place in them by the repeated ploughing and turning 
up to the influence of the atmofphere, but by their ad¬ 
mitting the particles of the manures that may afterwards 
be applied to be blended and incorporated with them in 
a more minute and extenfive manner; and their becom¬ 
ing fo perfectly aerated, as that the different proceffes that 
have been mentioned may take place and properly pro¬ 
ceed, fo as to form in them fuch fubftances as have been 
found of utility in aiding the growth of crops ; and which 
NDU 
could not poflibly have been produced without fuch pul¬ 
verization as is found to be the effect of fallowing. 
It may be further ftnted likewife, that the degree of 
friability and mellownefs that is produced in this way in 
fuch foils has alfo other advantages, fuch as thofe of ad¬ 
mitting the roots of the growing plants to penetrate them 
with greater facility, and prefintinga more extenfive fur- 
face for them to draw their nourifhment from. And, as 
in lands of thefe kinds there is a conftant tendency to 
throw up abundant crops of weeds, it is perhaps only by 
the frequent turning over of the foil, and the tearing of 
them up by harrowing, as is the cafe in fummer-fallow¬ 
ing, that they can be effectually eradicated and deftroyed. 
It is principally in this view, that the working of fuch 
foils in the early fpring or fummer months becomes ft* 
particularly neceflary, as, at the period in which the feed 
is to be put into the ground, neither the feafon nor the- 
ftate of the weather wiil admit of their being fufficiently 
broken down and reduced by ploughing, or the weeds to- 
be deftroyed. And it may be added, that wet lands, by 
being turned over during the winter feafon, are'liable, in- 
many cafes, to become more ftifF and adhefive, by which 
the roots of the crops muft be more limited and confined 
in their means of acquiring nourifhment from them. It 
has been lately well obferved, that, when land of a dry 
gravelly quality gets foul, it may be eafily cleaned with¬ 
out a plain fummer-fallow ; as crops, fuch as turnips, &c. 
may be fubftituted in its place, which, when drilled at 
proper intervals, admit of being'ploughed between as of¬ 
ten as neceflary; whereas wet foils, which are naturally 
unfit for carrying fuch crops, muit be cleaned and brought 
into good order by frequent ploughings and harrovvings 
during the fummer months. 
Indeed it is llren,uoufly contended by fome agricul¬ 
tures, that the moll judicious intermixture of crops updn 
clay foils will not preclude the necefiity of a fummer-fal¬ 
low ; though it is admitted that it may go a great way in 
preventing the necefiity of its being fo frequently repeat¬ 
ed. But a very able writer on hufbandry, whole expen- ■ 
ence has been confiderable, while he allows that there is 
no queftion at all of the merit of fallowing when com¬ 
pared with bad courfes of crops, and who thinks, that, if 
the hufbandry is riot correct in this refpedt, the fallowilt 
will certainly be a much better farmer than his neigh¬ 
bours, contends that there are courfes which will clean the 
fouleft land as well as any fummer-fallow, by means of 
plants which admit all the tillage of fuch as fallow. Cab¬ 
bages, he fays, a,re not planted before June or July ; win¬ 
ter tares admit of three months’ tillage, if tillage be want¬ 
ed. Beans, well cultivated, will preferve .and clean, which 
has been cleaned by cabbages; and in any cafe two fuc- 
cefiive hoeing-crops are, he thinks, effective in giving po- 
fitive cleaunefs. Thefe obfervations are not, he adds, theo¬ 
ry ; they are practice: and it is high time that mankind 
fhould be well perfuaded, that the right quantity of cat¬ 
tle and fheep cannot be kept on a farm, if thi fallows of 
the old fyftem are not made to contribute to their fupport. 
There are probably, however, many fituations of clayey 
foils lo exceedingly ftifF and wet, that though turnips, 
cabbage, or bean-crops, may be grown upon them, it 
cannot, from the great labour and difficulty of their pre¬ 
paration, and the high degree of injury that muft be done 
in the eating them or cariying them off the land, be to 
much advantage, or fuch as to admit of that fort of cul¬ 
ture during their growth that will keep the ground per¬ 
fectly clean from weeds. 
In fuch cafes no courfe of crapping, however judicious, 
can probably be effectual in this refpect; it is indeed well 
known to fuch practical farmers as have had the manage¬ 
ment of foils of tnis nature, that it is fcarcely poflible to 
be effected even by fummer-fallowing itfelf. It has alio 
been juftly obferved, that foils of this defcription are fo 
frequently, from necefiity, ploughed over when wet, that 
an adhefion and foundnefs are produced that cannot be 
removed 
