+------------------+------------------+--------------------+------------+------------------+ | Liber Ignium.[80]| Liber Ignium.[81]| De Mirabilibus.[82]| Kyeser.[83]| Hartlieb.[84] | | _cir._ 1300. | _cir._ 1350 | _cir._ 1350. | 1405. | _cir._ 1425. | +------------------+------------------+--------------------+------------+------------------+ | Sulphur. | Sulphur. | Sulphur. | Sulphur. | Sulphur(Oil of). | | Quicklime. | Quicklime. | Quicklime. | Quicklime. | Quicklime. | | Oil | Turpentine. | Naphtha. | Petroleum. | Mastic. | | Gum Arabic. | ... | Wax. | Wax. | Gum Arabic. | | ... | ... | Oil of Balm. | ... | ... | +------------------+------------------+--------------------+------------+------------------+ _N.B._—None of these mixtures professes to be the official Greek sea-fire, the exact composition of which is unknown; but the “De Mirabilibus” mixture is probably a close approximation to it. Although called sea-fires here, they were not so called by their western authors, who were ignorant of the use and even of the name of sea-fire. The first four recipes are described as mixtures which will ignite “when rain falls upon them.” Hartlieb alone foresaw that such mixtures would ignite “if thrown upon water.” Such a mixture would have completely fulfilled the four conditions already mentioned. First, the secret of its composition was easy to keep, since it lay in the choice and proportions of known ingredients; not in the use of one special and unknown substance (such as saltpetre), smuggled privily into the Arsenal[85] with a mystery which was certain to excite the curiosity of a people who “spent their time in nothing else, but either to tell or to hear some new thing.” Secondly, it was literally a “sea-fire” or “wet-fire,”—a fire which was ignited by water and which burned on its surface. Thirdly, its combustion gave rise to a considerable volume of vapour and a series of small explosions in the air. Fourthly, from the mode of its combustion it was unsafe to handle after ignition, and it was necessarily discharged from siphons. This simple explanation of the sea-fire[86] sweeps away the insurmountable difficulties raised by the saltpetre theory. We have no longer to believe in the patriotic silence of Byzantine officials, workmen and sailors, maintained for five hundred years; we have no longer to admit reluctantly that saltpetre was known in Greece, where it occurs in comparatively scanty quantity, five hundred years before it was known in the great natural storehouse of this salt, Asia; we have no longer to suspect the whole body of Greek writers on alchemy and pharmacy, from the seventh to the thirteenth century, of having entered into a vast conspiracy of silence to hide