Encyclopædia Britannica, Ninth Edition/Greek Fire

GREEK FIRE is properly the name applied to the inflammable and destructive compounds used in warfare in the Middle Ages, and particularly by the Byzantine Greeks at the sieges of Constantinople. It was the precursor of gunpowder, and of such modern compositions as dynamite and nitroglycerin, and was frequently accessory to gunpowder for many years after its invention. But combustible mineral substances were employed in war much earlier than the Middle Ages. Greek fire has borne the names wildfire, maritime fire, wet fire, fire-rain; called by the French feu grégeois, by the Germans grieschisches Feuer; it was “the oil of cruel fire” of the Chinese, the oleum incendiarum of the Romans, and the πῦρ ὑγρόν, liquid fire, of the Greeks. Procopius designates it “Medea's oil.” Cinnamus (12th century) describes it as πῦρ Μήδικον, Median fire, the black clays of Media and Persia supplying the principal constituent. Used chiefly at sieges and in naval engagements, it was poured from cauldrons and ladles on the besiegers and their engines, or vomited through long copper tubes from the mouths of hideous figures set in the prows of ships. Sometimes flax was twisted and saturated with the liquid, then fired, and projected on arrows, lances, and javelins. At sea it was often flung in pots and phials. The heavy ballista and other military engines were pressed into the service in early times for scattering this destructive compound in large quantities, often in barrels. Owing to the viscid nature of Greek fire it adhered to whatever it touched. It is described as producing a thick smoke, a loud explosion, and a fierce flame, and as being quickened by the element of water. Sea-water is specially mentioned as intensifying its inflammability; and whenever it fell among ignitible materials terrible havoc was occasioned. The sight and sound of the engine discharging the torrent of fire carried dismay into many a warrior's breast. The devastating consequences pictured by early writers are probably overdrawn, but there can be no doubt that they were formidable. Liquid fire has been used in warfare from very remote times, as may be seen in the Assyrian bas-reliefs in the British Museum. Greek fire, properly so called, is said to have been employed for the first time against the Saracens in the siege of Constantinople, 673–679, the inventor being a Syrian named Callinicus. The art of compounding Greek fire was concealed at Constantinople with the most jealous care; indeed it was to Greek fire, while the secret of its manufacture was kept, that the city owed in great measure its safety. In 1755 two Frenchmen, Gaubert and Dupre, are reported to have rediscovered the art so carefully concealed by the Byzantine Greeks; but they were prohibited from making it known. Various projects for the use of this or similar preparations have been advocated in recent times. The ingredients and relative proportions of the composition are not exactly known, the secret having been very successfully preserved. The Syrian historian Michael applies the name naphtha to the "newly invented" Greek fire; and this probably was the destructive agent of the Assyrians, Persians, and other Eastern nations, springs of naphtha abounding in their territories. According to the author of L'Espirit des Croissades, Greek fire was compounded of the gum of the pine and other resinous trees reduced to powder, with the addition of brimstone, naphtha, and other bitumens. Fanciful substances were included, such as the water of a particular fountain in the East, duck's grease, &c. Friar Bacon mentions two of the ingredients, saltpetre and sulphur, but conceals the rest. Giambattista Porta states that Greek fire is made by boiling together willow charcoal, salt, ardent aqua vitæ, sulphur, pitch, frankincense, threads of soft Ethiopian wool, and camphor. In a Spanish MS. of the 13th century in the Bodleian library a different receipt is given; and others will be found in the Liber ignium a Marco Greco præscriptus, &c., Sloane MS. (Brit. Mus.) 323; in the Sloane MS. 7, Modus faciendi ignem græcum, &c. From all that has been said it appears that naphtha—otherwise petroleum, rock oil, or Rangoon tar—and sulphur, and sometimes nitre, were the principal constituents; and the use of these, or two of them, in varying quantities, with the charcoal mentioned by Porta, no doubt gave birth to gunpowder. An invention by Niepce comprised benzol and potassium, in the proportion of 600 to 1, placed in a glass vessel; and Disney's is believed to have included a solution of phosphorus in sulphide of carbon or chloride of sulphur. But of all the spontaneously combustible liquids, Bunsen's kakodyl, As₂(CH₃)₄, is probably the most deadly, while it is far in advance of the old Greek fire as a destroyer of life. A combustible used at the siege of Charleston, U.S., in 1863 consisted of (1) saltpetre, sulphur, and lampblack, pressed into small tubes, and (2) coal tar naphtha, placed in shells or pumped through hose. The best military authorities appear now to agree that Greek fire is unsuitable for purposes of war, and comparatively little use has been made of it in recent times.

For further details see Recepta varia de præparatione ignis Græci, Sloane MS. 232; also Arundel MS. 164; Beckmann, Gesch. der Erfindungen; Dufresne L'Esprit des Croissades, Amsterdam, 1780; Gibbon; Grose, Mil. Antiq.; Hoefer, Hist. de la Chimie; Joinville, Memoirs, 1807; Libri, Hist. des sciences math. en Italie; Mechanics' Magazine, 18th August 1844; Napoleon III., Études sur . . . . l'Artillerie; Poggendorff, Gesch. d. Physik, 1879; Roy. Instit. Quart. Journ., xiv.; Scoffern, Projectile Weapons, 1858; and the writings of the Byzantine historians.