Wall and Sawkins mention pyrites and gypsum as being found: but we saw none, as far as I recollect.

All these must have been carried up from a considerable depth by the force of the same gases which make the little mud-volcanoes.
Now and then this 'Salse,' so quiet when we saw it, is said to be seized with a violent paroxysm.

Explosions are heard, and large discharges of mud, and even flame, are said to appear.

Some seventeen years ago (according to Messrs.

Wall and Sawkins) such an explosion was heard six miles off; and next morning the surface was found quite altered, and trees had disappeared, or been thrown down.