109 
the weight of from a pound to a pound and a half : this unusual 
size, however, is only met with in moist warm grounds. Here 
they lie nearer the surface of the soil. The drier the soil is, the 
deeper they are produced in it ; but are usually so much the 
smaller : to this the vicinity of springs is the sole exception. 
146 Truffle, Cultivation of. Upon the first production of the 
Truffle its size is scarcely perceivable ; as it proceeds in its 
growth, the earth that is around it is pressed together and jnished 
off. On this account the Truffle can prosper in none but a loose 
soil. If the soil is everywhere equally loose, the Truffle as- 
sumes a globular form ; but this is changed if there is on one 
side a greater opposition than on the other ; as, for instance, by 
a root or a stone. Hence the different forms of the tubers may 
be explained. Where the soil is most moist, whether above or 
under the Truffle, there it will either rise up or sink deeper. 
In laying out Truffle beds a distinction must be made between 
wood land and garden land. The former needs not much jue- 
))aration, and promises a surer profit than garden land, with 
which must be artificially mixed those species of earth that, in 
the former, have for several years been accumulated by nature. 
He, therefore, who can take for new Truffle beds wood land, es- 
pecially that which for centuries has produced the above men- 
tioned trees, spares both time and expense. But whether the 
'J’niffle plantation be made in a wood or a garden, the first re- 
(piisite is a somewhat moist soil in a low situation. The ground 
itself, however, must not contain any sharp or sour component 
parts, but must be mellow and fertile. Least of all are adap- 
ted to the purpose, situations in the neighbourhood of morasses 
or turf moors ; and especially those low situations the subsoil 
of which is full of saline or sour matter. This is easily known 
by the reeds, horsetail, (Equisetum,) coarse kinds of grass, and 
mosses, wliich grow upon their surface, and, whether green or 
dry, are rejected by cattle and sheep, or only eaten by them 
from excessive hunger. He who has no such mellow soil, in a 
depressed situation, upon his j)roperty, may most easily form 
it by art in the neighbourhood of springs, or at the foot of a 
rising ground ; but the first plantation is thereby proportionally 
rendered more expensive. The ground designed for the culti- 
vation of Truffles must, in the first place, be dug out from four 
feet to five feet deep, and be lined at the bottom, and on the 
155 ADCTABIUM 
