Every body has written about the Grotto del Cane and its poisonous vapors, from Pliny down to Smith, and every tourist has held a dog over its floor by the legs to test the capabilities of the place.

The dog dies in a minute and a half--a chicken instantly.

As a general thing, strangers who crawl in there to sleep do not get up until they are called.

And then they don't either.

The stranger that ventures to sleep there takes a permanent contract.