Cultivation of Tn/ffles, 4 19 



the plantations. This is found naturally only in particular situ- 

 ations; for which reason truffles do not grow everywhere. That 

 which is accidentally in the new plantation is looked upon as 

 a welcome present, and those inateiials only are mixed with it 

 which the raising of truffles indispensably requires. A ferru- 

 ginous calcareous soil is generally too compact, seldom too loose, 

 and frequently not sufficiently ferruginous. The first fault may 

 be remedied by the addition of ferruginous sand ; the second, 

 by a mixture with loam; and the third may be remedied by 

 beating ferruginous sandstone (which is to be had almost every 

 where) to fine sand, and mixing a fourth, at the most a third, 

 part of it, with the natural soil. If iron-stone is not to be had, 

 the want of it must be su})plied by iron shavings, iron filings, 

 sparks and other cheap small refuse which falls from iron in 

 manufacturing it : this must be added to the mixture of earths, 

 and made to rust and dissolve by the addition of moisture. 



A calcareous or chalky marl forms the groundwork of all 

 artificial mixtures of soils for the cultivation of the truffle. 

 When this is to be had in the neighbourhood, it is mixed with 

 the fourth part of iron sandstone. If this marl be not in the 

 environs, then finely beaten calcareous stone or beaten chalk 

 must supply its place: to this must be added from the fourth to 

 the third part of ferruginous sand, and the whole mixed to- 

 getlier as uniformly as })os.sible. Witli this artificial calcareous 

 marl the truffle- bed (which has been dug out from 2^ ft. to S ft. 

 deep) is filled up a foot high, in the {)lace of the natural earth. 

 It is advantageous when the pit, which is dug out for that pur- 

 pose, before it is filled with the new soil, is lined on the sides and 

 bottom with unburnt calcareous stone. By this means, not only 

 will mice, and several kinds of worms, be prevented from esta- 

 blishing themselves in the new truffle beds, and preparing to 

 destroy the young germs of the truffles, but sudden heavy rains 

 will be prevented from occasioning an injurious mixture of the 

 different kinds of earths. Where calcareous stone is not to be 

 had, sandstone may be used instead of it, especially if it contains 

 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. 



Ilj when the pit is dug out, a compact subsoil is met with, 

 for example, a loamy bottom, the paving of the bottom of the pit 

 is supeifluous: it would obstruct the binding of the under 

 strata with the new-laid bottom of the tiuffle plantation. It 

 sometimes happens, 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 to spend 



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