think, a strong support to something like a poisonous material existing
in the atmosphere in such spots; but I merely offer doubts. I hope the
progress of physiology and of chemistry will at no very distant time
solve this important problem." Ambrosio now came forward, and bowing to
the stranger, said he took the liberty, as he saw from his familiarity
with the cicerone that he was well acquainted with Paestum, of asking him
whether the masses of travertine, of which the Cyclopean walls and the
temples were formed, were really produced by aqueous deposition from the
River Silaro, as he had often heard reported. The stranger replied,
"that they were certainly produced by deposition from water; and such
deposits are made by the Silaro. But I rather believe," he said, "that a
lake in the immediate neighbourhood of the city furnished the quarry from
which these stones were excavated; and, in half an hour, if you like,
after you have finished your examinations of the temples with your guide,
I will accompany you to the spot from which it is evident that large
masses of the travertine, marmor tiburtinum, or calcareous tufa, have
been raised." We thanked him for his attention, accepted his invitation,
took the usual walk round the temples, and returned to our new
acquaintance, who led the way through the gate of the city to the banks
of a pool or lake a short distance off. We walked to the borders on a
mass of calcareous tufa, and we saw that this substance had even
encrusted the reeds on the shore. There was something peculiarly
melancholy in the character of this water; all the herbs around it were
grey, as if encrusted with marble; a few buffaloes were slaking their
thirst in it, which ran wildly away on our approach, and appeared to
retire into a rocky excavation or quarry at the end of the lake; there
were a number of birds, which, on examination, I found were sea swallows,
flitting on the surface and busily employed with the libella or dragon-
fly in destroying the myriads of gnats which rose from the bottom and
were beginning to be very troublesome by their bites to us. "There,"