VOL. XVII.] PHILOSOPHICAL TRANSACTIONS. 535 



with many white veins or threads; the whole is of a globose figure, though 

 unequal and chinky (fig. 2). 



What these truffles are, neither the ancients nor moderns have clearly in- 

 formed us ; some will have them to be callosities, or warts, bred in the earth : 

 others call them subterraneous mushrooms. They are most tender in the 

 spring; though after showers and sultry weather they may be plentifully found 

 in autumn: the wet swells them, and lightning may dispose them to send forth 

 their particular scent so alluring to the swine; for some of the ancients called 

 them ceraunia. 



Mr. Hatton observed fibres issuing out of some of these tubera, (as fig. l) 

 which lay spit deep under ground ; so that perhaps they may be plants sui gene- 

 ris, and their furrowed papillae analogous to, if not real, seed-vessels ; for several 

 vegetables bear their seed near the root, as the trifolium subterraneum tricoccum 

 reticulatum fiosculis longis albis, most of the arachidnas, and some other pulse 

 which flower above, but seed under ground. As to the truffles lying so deep, 

 that is common to many roots, that shoot up stalks above the earth: to instance 

 only in that lathyrus tuberosus, called commonly chamaebalanus and terrae 

 glandes, in English, pease-earthnut, dug up and eaten by the poor people. 

 The roots of our bulbocastanum, of the umbelliferous tribe, commonly called 

 kepper-nuts, pignuts and gernuts in the north, lie very deep, and fatten hogs, 

 which are very greedy of them. 1 have often observed the shepherds and boys 

 ill Yorkshire digging them up for a delicate dish : perhaps this is the nucula 

 terrestris septentrionalium of Lobel, and the apios of Turner. 



Fig. I , represents one of the tubera terrae whole, the papillae and fibres being 

 observable. Fig. 2 is the same truffle cut through the middle to show the in- 

 side full of whitish veins. 



Account of an Earthquake in Sicily : in a Letter from Mr. Martin Harlop at 



Naples. N° 202, p. 627. 



It seems highly probable, that these tremblings of the earth proceed from 

 the same incensed matter, which, finding a way at other times through the 

 Mongibello, breaks out so furiously in smoke and fire; as appears by the 

 tragedy of Catania. The eruptions of these mountains are of two kinds : the 

 one not so violent as much to disturb the adjacent country; and this happens 

 once in two or three months, and lasts three or four days. The other is more 

 furious, and of longer continuance, and is observed at Naples to happen to 

 Mount Vesuvius once in about 80 years. Of these, the last, which was in 

 1632, was so very violent, that it threw the rocks 3 miles into the air. Now 



4 B 2 



