49G 
THE COMMON TRUFFLE (TUBER CIBARIUM). 
BY JABEZ HOGG, F.L.S., M.R.C.S., ETC, 
I T is, perhaps, not very generally known, that the curiously 
formed, irregular-looking mass, so much esteemed for its deli- 
cious taste, and sought after as a luxury, the truffle, is in truth 
a species of mushroom, more properly speaking, a subterranean 
puff-ball, or fungus. 
The common truffle. Tuber cibarium ; Li coper don Tuber of 
Linnaeus, and described by Pliny under the name of Tubera 
sincera, appears to have been well known to the ancients. The 
truffle of our markets occurs in rounded nodules, varying in 
size from a nut to that of a large potato, irregular in form, with 
a rough warty-looking black outer coat. It grows a few inches 
below the surface of the ground in several parts of England, 
Covent-garden Market receiving its supply from the downs of 
Wiltshire, Hampshire, and Kent, as well as France and Ger- 
many. Its existence, entirely removed from the action of light, 
is an anomaly even among plants of the fungus kind ; for light, 
although not in a large degree necessary even to the fungus, is 
almost always indispensable to its full development. It would, 
therefore, be most difficult to discover, if it were not for a pecu- 
liar and penetrating odour, which dogs are taught to recognize; 
and by the aid of these useful animals its presence is detected 
hidden beneath the soil. Pigs are very fond of them ; and in 
Italy advantage is taken of their instinctive knowledge of the 
spots, and natural propensity to dig them up, to gather a larger 
supply. 
France produces three excellent varieties, the truffe de Peri- 
gord, with black flesh ; the truffe de Bourgogne, with white 
flesh ; and a third -with violet flesh. The first is much esteemed, 
on account of its odour and tenderness, and from it is made a 
finer seasoning or flavouring ingredient for the luxuries of the 
table. 
Riegel, with the desire of discovering the peculiar chemical 
principle which gives odour and flavour to the truffle, carefully 
analyzed the Perigord variety, and found it consisted of a brown 
fatty oil, with traces of a volatile oil, an acrid resin, osmazone, 
mushroom sugar, nitrogenous matter insoluble in alcohol. 
