430 Indications of the Fertility or Barrenness of Soils. 
the hand as snap. I am satisfied that to analyze the upper and 
under soils of any part of such a field as this is useless for the purpose 
of ascertaining its degree of fertility or barrenness, as regards the 
whole 10 acres. I apprehend it will be necessary, before che- 
mistry will be able to decide the relative fertility or barrenness 
of a whole farm, or parish, or district of country, or even a single 
field, to examine every stratum that crops out in such farm, parish, 
district, or field, and the subsoil immediately under it; also its 
colour, consistency, and the vegetation thereon ; and such, I sup- 
pose, are the opinions of natural philosophers, and consequently 
further information is required, to which I will endeavour to con- 
tribute as far as my experience and observations will serve me. 
I have been the whole of my life in agricultural districts, and 
for the greater part of the last thirty years have been engaged in 
farming pursuits, and have travelled over a great part of Berk- 
shire, Wiltshire, Oxfordshire, and Gloucestershire, and also some 
parts of VVarwickshire and Worcestershire ; and have made m;iny 
observations on the different soils as 1 passed through the country, 
some districts of which I saw at all seasons of the year, and for 
years together. I will begin my observations on the chalk forma- 
tion, the soil on which I was born. My father occupied a farm 
of 700 acres at the foot of the chalk hills, about midway between 
Swindon in Wiltshire, and Wantage in Berkshire ; the farm ex- 
tended to the length of six miles from end to end, and contained 
four sorts of soil : the upper end has a brown super or top soil, 
with chalk under, part arable and part downs ; then comes the 
white land, with a white stone under that, all arable ; next, the 
whitish, or ash-coloured land, with a subsoil of alternate veins of 
soapy marl and white gravel, mostly arable. The lower part of 
the farm is all pasture, with a clay top-soil, mellowed a little with 
vegetable matter; the subsoil a very tenacious yellow clay. Jn 
cultivating the land on the chalk we invariably found the darkest 
coloured soil to produce the best crops of every description ; and 
this occurred mostly in the lowest situations. As the land be- 
comes more elevated the chalk rises nearer the surface, which, 
by the action of the plough, is mixed with the top-soil, and gives 
it a paler colour ; and, in addition to this index of comparative 
barrenness, we always found such soils more thickly covered with 
small stones : and this fact is observable on the worst part of the 
downs ; but here the stones are almost black from the action of 
the elements. Another feature of this part of the country is an 
unerring guide to distinguish the good from the poor soils ; the 
hedge-rows (where there arc any) are always strongest on the 
darker land, and short and stunted on the light-coloured; and 
when a hedge may chance to go up the ascent of a hill, it will 
hardly grow at all towards the top. I am not aware of any plant 
