1846. 
THE CULTIVATOR. 
MaareMiBsmiaasawzBaiw^ 
145 
COLMAN’S EUROPEAN AGRICULTURE—PART V. 
Classification of Soils. —On this point Mr. Col- 
man uses no “ scientific distinctions,” preferring such 
terms as even the commonest farmer can understand. 
He thinks that “ for all practical purposes, soils may be 
ranked under five different heads—sandy, clayey, calca¬ 
reous, peaty, and loamy. A sandy soil is that in which 
sand abounds; clayey, in which clay; calcareous, in 
which lime in some form prevails; peaty, in which 
peat; loamy, in which a-rich loam abounds.” * * * 
<c In general, where there is found in a soil 80 per cent, 
of sand, it must be pronounced a sandy soil; but it is 
not always easy to class a soil which is of a mixed cha¬ 
racter, and say what kind of element predominates.” 
When speaking- of the “physical properties of 
the soil,” he alludes to a theory advanced by Liebig 
in his late treatise on artificial manures, that the sys¬ 
tem of draining has been carried in England to an inju¬ 
rious extent, by allowing the soluble parts of manure 
to be washed down beyond the roots of plants. Lie¬ 
big's language is,—“ The system of drainage which of 
late has been so extensively followed in England, brings 
the land into the state of a great filter, through which the 
soluble alkalies are drawn off in consequence of the per¬ 
colation of rain, and it must therefore become more defi¬ 
cient in its soluble efficacious elements.” He, Liebig, 
then goes on to state that he has “succeeded in com¬ 
bining the efficacious elements of manure in such a 
manner as that they will not be washed away; and thus 
their efficacy will be doubled. Owing to this, the in¬ 
jurious consequences of the present system of draining- 
are removed; agriculture is placed upon ascertain prin¬ 
ciples as well arranged manufactories,” &c. 
In reference to the distrust which Liebig would thus 
throw on the practice of draining, Mr. Colman remarks, 
that the beneficial results of the system have been so 
marked and striking, that it may, in his opinion, still 
be pursued “ with a good degree of confidence. He re¬ 
fers to an example he had lately seen where a field of 
turneps, on a thin, dry, and light soil, in which sand 
abounded, the beneficial effects of thorough drainage” 
were shown in the crop being better by one half on the 
drained, than on the undrained portion of the lot. In 
relation to the brilliant results which farmers may be 
led to expect from the use of the artificial compound 
spoken of, Mr. C. expresses some doubts, not however, 
he says, in any captious Spirit, knowing how much agri¬ 
culture must in the end, owe to science, and being ready 
to hail with the highest satisfaction any triumph it may 
achieve.” 
In reference to peaty soils, which are formed 
principally of decayed vegetables, it is observed—“If 
vegetable matter were, as is often reckoned, the best 
food of plants, it would seem as though no soil could 
be so fertile as that of peat. This is not found to be the 
case, however, but for reasons not so well established 
as the fact.” In ordinary cases he thinks it must be ad¬ 
mitted that—“the fertility of a soil essentially corres¬ 
ponds to the amount of vegetable matter found in it, 
whether it supplies, in any degree, the actual substance 
of the plant, or, by its gradual decay, be merely the 
vehicle of transmitting for its nourishment the gases out 
of which its substance is to be composed. It is certain 
however, whatever may be the philosophical reason in 
the case, that pure unmanufeeiured peat does not form a 
nourishing soil or substance for plants, other than those 
to which a wet soil is particularly congenial, and that 
it cannot be made so but under a particular management 
wffiich I shall presently describe. The vegetable mat¬ 
ter of which it consists, being once thoroughly reduced, 
and mixed with other substances of an alkaline charac¬ 
ter, is rendered a most enriching manure for most kinds 
of land, though a much less substantial one than is gene¬ 
rally supposed. One of its great uses is that of an ab¬ 
sorbent, taking up the liquid matters which would other¬ 
wise be lost.” 
Mr. Colman informs us that the reclamation of bog 
lands has been carried on to a great extent in England 
and Ireland. In the latter island, he witnessed the ope¬ 
rations of one company which has at this time, five 
thousand acres of bog in the process of improvement. 
He thinks the peat bog of the United Slates, as well as 
England, ‘‘ may be rendered in the highest degree pro¬ 
ductive and profitable.” In relation to the bog of salt 
marshes, it is remarked that they are of a “ different 
character from fresh-water peat-bog.” The vegetable 
matter being chiefly marine plants, “ which have served 
as a kind of net-work to collect the earthy matter 
brought among them by the tide. The quantity of salt 
intermixed with these deposites, gives them a peculiar 
character. They are favorable to the production of 
plants congenial to them; but other plants cannot be 
made to grow upon them till they are thoroughly de¬ 
composed; and in that case no soils yield a more luxu¬ 
riant or richer vegetation. In truth they require to be 
reduced to the state of fine mould, and the greater portion 
of the saltness exhausted, which time itself will effect 
where they are kept from the access of the tide, in order 
to be in a condition favorable to the growth of other 
than marine or saline plants.” 
Under the head of Humus, or Vegetable mould, 
Mr. Colman enters somewhat into a discussion of the 
point assumed by some writers, that humus, or vegetable 
matter, is not taken up as the food of plants. He quotes 
from Liebig in reference to the fertility of the soils in 
the neighborhood of Mount Vesuvius. “ The land in the 
vicinity of Vesuvius,” says Liebig, “ may be considered 
as the type of a fertile soil, and its fertility is greater or 
less in different parts, according to the proportion of 
clay or sand which it contains.” These soils, on ac¬ 
count of*their origin, it is thought “cannot possibly 
contain the smallest trace of vegetable matter; and yet 
it is well known” continues Liebig, “that when the 
volcanic ashes have been exposed for sometime, to the 
influence of the air and moisture, a soil is gradually 
formed in which all kinds of plants grow with the 
greatest luxuriance. This fertility is owing to the al¬ 
kalies which are contained in the lava, and which by 
exposure to the weather are rendered capable of being 
absorbed by plants.” But “ thousands of years,” it is 
added, “ have been necessary to convert stones and 
rocks into the soil of arable land.” 
Mr. Colman thus comments on the above:—“ General 
experience would seem to show that soils without any 
vegetable mould are not productive, and most practical 
farmers would prefer, of all others, a soil where the 
vegetable matter, well compounded, existed in abun¬ 
dance, forming, as it is termed, a deep and rich loam . 
But it would seem that in the case to which Liebig re¬ 
fers, thousands of years are necessary to render a mass 
of lava fertile, and in such a case it might be fairly pre¬ 
sumed that some vegetable matter might accumulate and 
produce the desired mixture.” Mr. Colman, however, 
observes, in further considering the subject, that the 
inference that Liebig believed the vegetable matter in 
the soil to be of “ no moment,” might not be quitejust. 
“He does,” says Mr. C., “ consider the humus of the 
soil as funnishing, in its decay, a necessary supply of 
carbonic acid to the plant in the process of germination, 
though of no use after the plant gets above ground; and 
he supposes that the manure of animals fed upon the 
product of the land return to the land those mineral 
elements which they took from it, and which are indis¬ 
pensable to their perfect formation. This maj' - be so, 
and in this view, he does not deny the value of vegeta¬ 
ble mould, or humus. But certainly,” concludes Mr. 
Colman, “there was nothing improbable in the suppo¬ 
sition that plants might have found some portion of their 
food in those decayed substances which once constitu¬ 
ted a part of the substance of their predecessors. In¬ 
deed, I see as yet no sufficient grounds to conclude that 
their office in supplying carbon to the growing plants 
ceases as soon as the plant is above ground, and able, as 
he supposes, to gain its whole supplies for itself from 
the atmosp .ere. It is quite certain that the growth of 
a forest would be checked, and the amount of humus 
in the soil be diminished, if all the decayed leaves and 
limbs which fall from the trees were constantly re¬ 
moved; and it is ascertain that the continual cultivation 
of land with supplies of manure, exhausts its vegetable 
