PISSASPHALTUM, EARTH-PITCH; a fluid, opaque, mineral body, of a thick consistence, strong smell, readily inflammable, but leaving a residuum of greyish ashes after burning. It arises out of the cracks of the rocks, in several places in the island of Sumatra, and some other places in the East Indies, where it is much esteemed in paralytic disorders. There is a remarkable mine of it in the island of Bua, (see BUA), of which the following curious description is given us by the Abbé Fortis. "The island is divided into two promontories between the north and west, crossing over the top of the latter, which is not half a mile broad, and descending in a right line towards the sea, one is conducted to a hole well known to the inhabitants. This hole extends not much above 12 feet, and from its bottom above 25 feet perpendicular, arise the marble strata which sustain the irregular masses that surround the top of the mountain.
"The place seemed to me (continues our author), so worthy of observation, that I caused a drawing of it to be taken. The hole AAA is dug out of an irregular stratum of argillaceous sandy earth, in some parts whitish, and in others of a greenish colour; part of it is half petrified, and full of numismals of the largest kind, lenticulars, and fragments, with here and there a small branch of madrepores, and frequently of those other fossil bodies called by Gesner cornua ammonis candida, minima, &c. The mass B is fallen from the height of the rock, and lies isolated. The excavation, made by some poor man in the softer matter, reaches a little below the extremity CC of the stratum DD. This is separated by the line EE from the stratum FF, which is of hard common marble, with marine bodies without flints. The upper part aa is of hard lenticular stone, interspersed with flints full of lenticulars. The mass H does not discover the divisions of its strata on the outside, and transpires very small drops of pissasphaltum, scarcely discernible; but the tears III of the same matter, which flow from the fissures and chinks of the whitish stratum DD, are very observable. They come out most abundantly when the sun falls on the marble rock in the heat of the day. This pissasphaltum is of the most perfect quality, black and shining like the bitumen Judaicum; very pure, odorous, and cohesive. It comes out almost liquid, but hardens in large drops when the sun sets. On breaking many of these drops on the spot, I found that almost every one of them had an inner cavity full of very clear water.
"The greatest breadth of the tears that I saw was two inches, and the common breadth is half an inch. The chinks and fissures of the marble, from whence this bituminous pitch transudes, are not more than the thickness of a thread; and for the most part are so imperceptible, that were it not for the pitch itself, whereby they are blackened, they could not by any means be distinguished by the naked eye. To the narrowness of these passages is, no doubt, in part owing the small quantity of pissasphaltum that transpires."
After some conjectures about the origin of this mine, our author proceeds to inform us that the pissasphaltum of Bus is correspondent to that fossil production which by Hasselquist, in his Travels, is called mumia minerale, and mumia nativa Persiana by Kempfer, which the Egyptians made use of to embalm their kings (A). It is found in a cave of mount Caucasus, which is kept shut, and carefully guarded by order of the king of Persia. One of the qualities assigned by M. Linnæus to the finest bitumen is to smoke when laid on the fire, as ours does, emitting a smell of pitch not disagreeable. He believes it would be very good for wounds, as the oriental mumia is, and like the pitch of Castro, which is frequently used by the Roman surgeons for fractures, contusions, and in many external applications. See MINERALOGY.