property lifus been veiy little attended to in a pliilosopliical point of view ; yet it is ofthe
highesc importance in culture. In general, soils wliich consist principally of a stiff white
clay, are with difficulty heated ; and being usually very moist, they retain thcir heat but
for a short time. Chalks are similar in one respect,— the difficulty with which they are
heated ; but, being drier, they retain tlieir heat longer ; less being consumed iu causing
the evaporation of their moisture. A black soil, containing much soft vegetable matter,
is most heated by the sun and air ; and the coloured soils, and the soils containing much
carbonaceous or ferruginous matter, exposed under equal circumstances to the sun,
acquire a much higher temperature than pale-coloured soils.
1173. When soils arc perfectly dry, those which most readily become heated by the solar
rays likewise cool most rapidly ; but tho darkcst-colourcd dry soil (that whicli contains
abundance of animal or vegetable matter, substances whicb most facilitate the diminution
of temperature), ivlicu heated to the same degree, provided it be witliin the common limits
of the effect of solar heat, will cool more slowly than a wet pale soil entirely composed
of earthy matter. Sir II. Davy “ found that a rich black mould, which contained nearly
one fourth of vegetable matter, had its temperature increased in an hour from 65° to 88°
by exposm-c to sunshine ; whilst a chalk soil was heated only to 69° under the same
circumstances : but the mould removed into the shade, where the temperature was 62°,
lost, in half au hour, 15°; whereas the chalk, under the same circumstances, had lost
only 4°. "Wc may also refer to the influence of black earth in melting snow, as practised
empirically on the Alps, and tried philosophically by Eranklin and Saussure.
The latter placed on the tup of the high Alpine mountain Cramont a box lined with
black cloth, with the side next the sun closed by three panes of glass at a little distance
apart the one from the other, and found the thermometer rise thirty degrees in tivo hours,
from the concentration of the sun’s rays. (L a Chymie appliquée, &c., torn. i. 82.) A
brown fertile soil and a cold barren clay were each artificially heated to 88°, having been
previously dried, they were then exposed in a temperature of 57° ; in half an hour the
dark soil was found to have lost 9° of heat, the clay had lost only 6°. An equal portion
of the clay containing moisture, after being heated to 88°, was exposed in a temperature
of 55°; in less than a quarter of an horrr it was found to have cooled to the tempcratrrre
o fth e room. The soils in all these experiments were placed hr small tin-plate trays, two
inches sqrrare, and half arr inch iir depth ; and the temperature was ascertained by a
delicate tJrcrmomoter. Thus the temperature of the surface, when bare and exposed to
the rays of the sun, affords at least one indication of the degree of its fertility ; and tho
thennoraetcr may be sometimes air useful histrarmcnt to tho purchaser or improver of
lands.”
1174. The moisture in the soil and subsoil materially affects thcir tempei-ature, and prevents,
as in the case of constantly saturated aquatic soils, their ever attaining to any gTcat
degi'ce either of heat or cold. The same obseiwation will apply to moist peaty soils, or
peat-bogs.
1175. Thus all soils are useful to plants, as affording them a fixed abode and a range
for tlieir roots to spread in search of food ; but some.are much more so than others, as
better adapted by thcir constituent parts, climate, inclination of surface, and subsoü, for
supplying and attracting food.
Sect. IV . O f discovering the Qualities o f Soils.
1176. The value o f soils to the cultivator is discoverable botanically, chemically, and
mechanically ; that is, by the plants that grow on them naturally ; by chemical analysis,
and by their sensible qualities of rouglmcss, smoothness, taste, smell, and fracture.
Subsect. 1. O f discovering the Qualities o f Soils hy means o f ihe Plants which grow
on them.
1177. Plants are ihe most certain indicators o f ihe nature o f a soil; for while no practical
cultivator would engage with land of whicli he knew only the results of a chemical
analysis, or examined by the sight and touch a few bushels which were brought to him,
yet every one, who knew the sort of plants it produced, would be at once able to decide
as to its value for cultivation.
1178. Tke leading soils fo r the cultivator are the clayey, calcareous, sandy, femiginous,
peaty, saline, moist, or aquatic, and diy. The follovdng ai-e the plants by which such
soils are distinguished in most parts of Europe : —
1179. Argillaceous. Common colt’s foot (Tussilàgo Fàrfara) ; goose tansy (Potcntilla
Aiiserina), silvery (argéntea), and creeping (réptans) ; yellow meadow me (2Íialíctrum
fl<àvum) ; Càrex, many species ; Juncus, vaiious species ; tuberous bitter vetch ( O'robus
tuberosas) ; greater bird’s-foot trefoil ( iò tu s major), and crow-footed (corniculatus) ;
officinal soapwort (Saponària officinalis) : but the Jùssilàgo Fárñu*a is a certain and
™
®P«cttacU {Verònica spicàta), little bedstraw (Gàlinm
pufeiUum), officinal gi-omwell (ZithospeiTnum officinale) and nurnle-blue Omrmn-n
S c C u ^ h S glomerata), hybrid prismatocarpus (Prisr
S S L ? / A Z m r f orbiculare), lyclmitis mullein
(, KOI bc^cum Xyclmitis), wayfanng tree ( Fiburimm Lantàna), common berbcn-y {Bérheris
f ta®« (Uebanthemum vulgàrc), common pnlsatiUa anemone
“ ft™-’ ” (Clematis Vitalba),
1181. Siheeotw. Three-lcavcd speedwell ( Ferimca tripliyllos) and Tcraal rvtrna'I
Italian viper s bugloss (X'chium italicum), smooth rnpturc-wort (Hcrniària glàbraì
and hairy (hirsuta) English oatehfly (Silèno anglica) and other sp e e ieZ L satawort
frLp y »
sélìa)®^’ Common son-cl (Rùmex Acetósa) and sheep’s son-cl (Aceto-
1183. Peafy Bilbcn-y (Facoiniiim MyrtiUus), bleabeny (uliginòsum-) cranhen-v
S Z p Z S u ( S e S a o L S ) " ™
fi nt rr-b: ? km>tgra.ss (iUéccbram vcrticillàtum), sea goosefoot
(Chuiopodiiim mai-itmmm) and shrubby (fniticòsum), kali saltwort (Salsòla ^ ¿ S )
(Ai-enfo-iaZai-hia, . 2 :
V id eZ nT ^ r fr'™'™® T“*™“ (Uafcriona dioica), -ivatcr violet (Hottònia palùstris)
I L , 7 nil Z Z y f r Valcrandi), marsh thysselinum (Thysselìiiumréalustre)
squaic-stalkcd epilobiiim/Epilobium tctragòimm), willow lythrnm (ijithi-um Salicmia)
T . in r n T r tl /.-».„„....-«-.J. /'TT'l.-r__... l a
:1 (Pùmex Acetosèlla),
l’òliumrértanY).'''“ “ “' “ ''‘»'-'“ ““V’ «fo«™ (./I'cyiios viugàris), field trefoil ( 7 ’ri-
U87. P/1C.SC p h n ts are not absolutely to be depended on, hwvever, even in Britain-
and in other countnra they are sometimes found in soils directly opposite Still tiré
cultirated saiiitfom Onobrj-ehis sativa) is ahnost always an iiid ic I tZ of a ealareons
r L i L o fT™ “" 5 ' I ft’«y i ’’«fr sandwort (Arenaria
l ì o l l o f i ? ™ s l'fP S son-cl (P ùmcx Acetosèlla), of the presence of
L I , I è réS ' “ r é ? " ?ft(-Pfrrogtoifo® commùnis) and the amphibious poly-
L Z e l l l l n - '® ? " ? «“ Phfo"“ ) grow on alluviffl soils, which yield excellent crops if
piopcily d ia lle d ; hut where the corn horse-t.aiI (Pquisètnm ai-vénse) grows froclv it
t h e l L l fl n “ I ''7 ? *™ - ®?®“ '- ’“ “ ft ooni-fleld pimpernel (Anag.-Ulis arvènsi’s),
tlie_coin-flcld madder (Sherard,a ai-vensis), the corn-field gromweU (Zithospérmiim
mvenso), and the salad lamb’s lettuce {Valerianélla ohtòria), grow on cultivated lands
wheie the sod is a strong bl.ack loam on a dry bottom ; when such a sod is wet tiré
b l t ì iA r e s I Z d palüstns) makes its appearance. A light sandy soil is kn’owii
by the picsciioe of the pm-ple archangel (Xamium piirpfireum) ; the shepherd’s purse
(CapscUa bursa pastoris). I f the parsley picrt {Alche,niUa A'phanos) is foundf the
tb Vk t i ' '"'P,*'°fr';?*ro i, 'f corn-field spun-cy (Spcrgida arvcnsis) gro-ivs very
thick, the ground has hkcly been i-endcrod too fino by tho harrow ; the common ragwort
o f iré : ,ft «™,'-fr«*fr o"'®™" (Cirsium ar-vèiiso), grow indisci-iminatdy
on light and strong loams, but always indicate a fertile soil The voi-nal draba (Priiba
vcina) and the annual knawcl (Scleranthus animus) grow on soils that are dry sandv
and poor in the extreme. The spiny rest-lian-ow (Onònis spinósa) is often fomid o i
d iy pasture, and where the soil is mcnmbent on rotten rock. The aquatic, pentv and
salme soils are almost every where indicated by thcir appropriate plants ; a proof is we
have before stated tlmt the climate and natural irrigation of plants have much more
infiuence on timi- habite than mere soil. {Galpine’s Compendium; Flora B r it ; Loudon's
lIortias B n t ; K en ts Hints; Farmer’s Mag. Feb. 1819; and the Quarterly Journal o f
Agric. for Aug. 1828.) a
StJBSECT. 2. O f discovering the Qualities o f Soils, ami thcir Adaptation to different Planta,
by Chemical Analysis. ’
1-1 ré'®? Ghemical analysis is much too nice an operation for general purposes. It is not
likely that many practical cultivators wDl ever be able to conduct die analytic process
p p 3
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