Ill 
iron ; or, at all events, either other natural stones, or artificial 
ones, made by the hands of men, may be made use of. The 
bottom of the pit must not, however, be paved so as to be water 
tight, in order that the water may sink into the subsoil, and not 
cause an injurious bog, instead of the moist depression that is 
intended. If, when the pit is dug out, a compact soil is met 
with, for example, a loamy bottom, the paving of the bottom of 
the pit is superfluous: it would obstruct the binding of the un- 
der strata with the new-laid bottom of the truflle plantation. It 
sometimes haj>pens, that, in digging out the pit, a bed of clay 
is met with, which is impervious to water. In such a case, it is 
better to leave the place and choose another, than instead of rais- 
ing Truffles, only to make a small bog. All tlie above prepa- 
rations are necessary for wood lands, and for plantations in large 
gardens and English shrubberies; but the further filling up of 
the pit is different for each place. In woods the soil contains 
much vegetable matter; but that is not enough, especially w'hen 
an artificial mixture of earths is undertaken. In order to ob- 
tain a very nutritious vegetable earth, let pure cow dung be 
carried into heaps in the spring, and left to fall into earth in 
the course of the summer. That is best which is collected as 
fresh as possible on pastures and commons. That it may not 
lose its nutritious matter through drought and heat, the heaps 
must be made in a shady place, be turned from time to time, 
and, in dry weather be often moistened. In autumn when the 
leaves fall from the trees, a I'ourth or fifth [>art of this earth is 
to be added to the natural wood soil ; and of fallen oak leaves, 
or, if these are not to be had, of fallen hornbeam leaves, as 
much in bulk as half the mixture amounts to : the whole must 
then be carefully mixed together. The pit is to be completely 
filled with the mixture, which is to be covered with a layer of 
oak leaves, of from four inches to six inches thick. A wood 
soil, with much vegetable earth from oak trees, requires a 
smaller addition of oak leaves, than a soil that contains less of 
It. The pit, when filled, is to be covered over with a thick layer 
of leaves, the scattering of which may be prevented by some 
earth taken from the mixture being spread over them, or by 
small branches of oak being laid upon them, and secured by 
stones. Such a cover of leaves is of great service to the plant- 
ing of Truffles; since by the moisture of the winter the most 
156 AUCTAUICM. 
