43.

Such are the phenomena. But Posidonius says, that the people being addicted to magic, and practising incantations, (by these means) consolidate the asphaltus, pouring upon it urine and other fetid fluids, and then cut it into pieces. (Incantations cannot be the cause), but perhaps urine may have some peculiar power (in effecting the consolidation) in the same manner that chrysocolla662 is formed in the bladders of persons who labour under the disease of the stone, and in the urine of children.

It is natural for these phenomena to take place in the middle of the lake, because the source of the fire is in the centre, and the greater part of the asphaltus comes from thence. The bubbling up, however, of the asphaltus is irregular, because the motion of fire, like that of many other vapours, has no order perceptible to observers. There are also phenomena of this kind at Apollonia in Epirus.