on the Temperature of Soils. 
137 
gated it with their habitual minuteness of research. The excellent 
translation of Professor Schiibler's learned work, in vol. i. of our 
Journal, renders it necessary to do little more than refer those 
persons to it who would pursue the same track of investig^ation. 
The inferences drawn by him, from experiments in the labora- 
tory, confirm generally those of Davy and Leslie. They are, 
however, chiefly of an elementary nature, and though more com- 
prehensive and precise, perhaps even more accurate, than those 
of the British chemists, this valuable treatise seems to present 
nearly the same blanks, as respects useful practical experiments 
on the bed of the soil, as the labours of our own countrymen. We 
shall all agree in the truth of the Professor's concluding para- 
graph ; viz., that — 
" Those very soils may be fertile for one country which become no 
longer so for another, under a change of external circumstances." 
It is the difference in these external — i. e. in the meteorological 
conditions of the surface of our globe which evidently renders 
identical systems of cropping, husbandry, and management, in- 
applicable to all climes. It is this difference, also, which must 
clearly point out to the agriculturist that if he would draw any 
useful deductions from experiments on the temperature of soil, they 
must be made on his own soil, or on like soils similarly circum- 
stanced. In Britain we have, generally speaking, to combat ex- 
cess of moisture, accompanied by a low and inconstant solar heat. 
It is one of my objects to show that, by establishing a free fas- 
sage for water through the soil, the greater heat of the surface 
may be carried downwards, and the mean annual temperature of 
the mass of the soil thereby permanently raised. This position, 
as well as the effect of removing excess of water, is well illus- 
trated by Schiibler in the section wherein he treats of the 
" Influence of Moisture on the Warming of Soils.''' He states 
" the depression of temperature arising from the evaporation 
of their ivater amounts to 11^° or I3^° Fahr. though the 
method by which he obtained this thermometric quantity is not 
mentioned, which is to be regretted. In the tenth section, how- 
ever, wherein he treats of the " Cajjacity of soils to develope 
heat within themseh es on being moistened, ' the following pas.sage 
occurs : — 
" The falling rain, in warm seasons, is many degrees colder than the 
lower stratum of the atmosphere, and the upper surface of the earth 
which it moistens ; so that the earth in hot weather becomes rather 
cooled than otherwise " 
This remark might seem to militate against the doctrine herein 
advanced, that the mass of the soil is warmed by rain when suf- 
fered to permeate it; but such opinion will, I think, vanish on 
