Causp.s of Fertility or Barrenness of Soils. 
175 
by the sc ience of chemistry, informing us, as it does with full 
certainty, what the soil contains and wliether it is likely to yield 
a fair return for our capital. Having satisfactorily settled this 
point, wo may fearlessly proceed to invest our money, first by 
thorough drainage, and afterwards in pulverising, so as to admit 
the atmosphere, which readily takes the place of the moisture 
removed by our drains. Any advice as to the best methods of 
draining would be out of place here, and, it is to be Loped, un- 
necessary ; since landowners and intelligent occupiers are by this 
time firmly persuaded of the vital importance of deep drainage, 
and the utter absuixlity of placing the drains just beneath the 
plough-bed, as was the practice 20 years ago. The advantages 
are incalculable : cultivation is lightened very often one-horse- 
power ; the temperature is raised ; germination more rapid and 
certain ; harvests accelerated ten days to a fortnight ; supplies 
of food often apparently inexhaustible are eliminated, which 
would otherwise have lain dead and useless ; and the number 
and variety of crops increased. The surface ceases to bake or 
puddle, hasty downfalls find ready access, and instead of stand- 
ing on the surface, stagnating in the subsoil, or running off with 
the best parts of the soil, the rain-water quietly passes away into 
the drains, fertilising in its passage. It may be stated as a rule 
that all real clay soils resting on an impervious subsoil, whether 
in tillage or pasture, require drainage ; without it they must be 
looked upon as the least remunerative, by its aid and judicious 
cultivation they may be rendered among the most productive. 
The practice of paring and burning the surface of stiff clays, 
much followed in some districts, may be noticed as bearing on 
the physical condition of such soils. The operation is usually 
performed at that period in the rotation when the land contains 
the most rubbish, as all surface weeds, insects, &c., are destroyed 
by the fire. The process is very simple. A paring-plough, 
either drawn by horses or pushed by men, slices off about 2 
inches of the surface, turning it over, in which state it remains 
till thoroughly dry. It is then got together into small heaps and 
burnt ; afterwards the ashes are spread and ploughed in. If lime 
is present in any quantity, the first shower causes the ashes to 
fall in a coarse powder, which gets thoroughly incorporated with 
the soil, the lime furnishing valuable food both directly and 
indirectly lo the succeeding crop. The effect of burnt clay is 
principally mechanical, opening the soil and rendering it more 
porous. It was formerly believed to absorb ammonia from the 
air, but recent experiments throw doubt upon this. The practice 
is found to answer exceedingly well, and, even if we do not burn 
the soil all over the field, we should never neglect any oppor- 
tunity of obtaining burnt earth. Borders of hedgerows, cleanings- 
