FIGURE 36. Noxious substances could be burned to create toxic smoke. Here, two men make a smoky fire. Attic vase painting, 510 BC.
(Toledo Museum of Art, Libbey Endowment, Gift of Edward Drummond Libbey)
In the fourth century BC, the Arthashastra provided formulas for creating burning powders whose fumes were supposed to drive enemies mad or blind, or cause them to sicken or perish immediately. Different smoke powders were concocted from the droppings of certain reptiles, animals, and birds, and mixed with genuine poisons and intoxicants. One lethal cloud was created by burning the bodies of venomous snakes and stinging insects along with the seeds of toxic plants and hot peppers. (Incidentally, hot peppers were used against enemies in the New World, too: in the sixteenth and seventeenth centuries, Caribbean and Brazilian Indians produced an early form of pepper spray against the Spanish conquistadors by burning piles of ground-up hot pepper seeds.) In India, turpentine and tree resins, charcoal, and wax were the flammable components of smoke powders.
Poisonous smokes that combined magical and toxic ingredients intended to kill or disorient enemies also appeared in ancient Greek and early medieval alchemy treatises. For example, Hippolytus (AD 230) claimed that burning powdered magnets would produce a deadly smoke. The addition of weasel feces to the magnets was supposed to create the sensation of an earthquake to terrify the foe.
Noxious smoke was hard to control and direct, and therefore most effective when employed in confined spaces like tunnels. As early as the fourth century BC, defenders of fortresses in China burned toxic substances and plants such as mustard seeds in furnaces connected by pipes to ox-hide bellows to pump poison gases into tunnels dug by attackers. In western Greece in AD 189, during the long Roman siege of Ambracia, the defenders invented a smoke machine to repel the Romans attempting to tunnel under the city walls. The Ambracians prepared a very large jar equal in size to the tunnel, bored a hole in the bottom, and inserted an iron tube. Packing the giant pot with layers of fine chicken feathers (burning feathers were known to create nasty fumes) and smouldering charcoal, they capped it with a perforated lid. They aimed the lidded end of the jar at the tunnelers and fitted blacksmith’s bellows to the iron tube at the other end. With this device—which calls to mind the primitive flamethrower at Delium—the Ambracians filled the passage with clouds of acrid smoke, sending the choking Romans hurrying to the surface. “They abandoned their subterranean siege,” was Polyaenus’s succinct comment.
Tunnelers mining under towers would employ wooden timbers to temporarily prop up the structure and then set them afire to cave in the tower. Opponents defending the fortresses dug countermines, and sometimes battles with incendiaries took place in the tunnels. A fascinating archaeological discovery in 1935 at Dura-Europos in Syria revealed evidence of such an underground battle. The Persians had besieged the Roman fort there in AD 265, and each side dug tunnels. The archaeologists found many weapons and skeletons (one in Persian armor) and a jar containing the telltale burnt residue of sulphur and pitch.
Plutarch (writing in about AD 100) described a chemical aerosol (particulates suspended in air) created by the Roman general Sertorius when he was trying to defeat the Characitani of Spain, in 80 BC. The Characitani lived in caves carved out of an impregnable mountainside. Frustrated, Sertorius rode around the hill “muttering empty threats.” Then, he noticed that his horse was kicking up clouds of caustic dust from the fine white soil at the foot of the caves. The soil may have been soft limestone or gypsum, since Plutarch compared it to “ash or unslaked lime powder”: limestone powder is a severe irritant. Sertorius also noticed that the prevailing winds blew each day from the north, and that the cave entrances faced north. Putting these natural facts together, Sertorius ordered his men to pile great heaps of the powdery soil in front of the caves. The next day as the north wind gathered force, the Romans stirred up the mounds and rode horses over the powder, raising great clouds that blew into the cave entrances. The Characitani surrendered after three days of enduring the choking, blinding dust.
In China, lime dust was used to make an early form of tear gas to quell riots. In AD 178, for example, an armed peasant revolt was quelled by horsedrawn “lime chariots” equipped with bellows to blow fine limestone dust “forward according to the wind.” This very effective fog was accompanied by stampeding horses with burning rags tied to their tails, loud drums and gongs, backed up by ranks of crossbow-men. The revolutionary forces were blinded, thrown into chaos, and “utterly destroyed.” When the dust interacts with the moist membranes of the eyes, nose and throat, the effect is corrosive. A poison aerosol described in the Byzantine emperor Leo’s Tactics was based on the same principles: pots of powdered quicklime (burnt lime) were thrown to form a caustic cloud that blinded and suffocated the enemy as they inhaled the dust.
Obviously, the blowback problems of wind-borne weapons would be an issue. Those who made use of toxic powders and smoke had to beware of unpredictable, reversing winds. Kautilya was highly aware of the danger and, in his chapter on poison smokes, he warned that the army must keep their “eyes secure” with applications of protective salves before deploying chemical aerosols. Only after “having applied these remedies to ensure the safety of himself and his army, should the king make use of poisonous smokes and other mixtures” against an enemy.
An Islamic manuscript from the early Middle Ages suggested the use of “smokes, prepared liquids, and ill-smelling deadly odors for causing damage to forts and castles and horrifying the enemy.” Noxious smokes have not gone out of style in modern arsenals. Dense clouds of smoke, chemicals weapons like mustard gas, pepper sprays, and tear gas still present blowback problems, however, requiring the users to don gas masks to avoid eye injury and inhalation.13
By the time of the Peloponnesian War, three combustible chemicals were known in the Mediterranean world—pitch, sulphur, and quicklime—and the first two were definitely used in warfare in during that era. Pitch, the highly flammable resin from pine trees, has a sticky consistency and burns hotly. Sulphur, a mineral characterized by corrosive combustion, burns at extremely high temperatures and creates sulphur dioxide gas. As it heats, sulphur liquefies, and also releases corrosive vitriol, sulphuric acid.
The choking effects of lime powder were apparently weaponized by Sertorius in the first century BC, but lime’s ability to spontaneously burst into flame was known centuries earlier. As Pliny remarked, lime “possesses a remarkable quality: once it has been burnt, its heat is increased by water.” Roasting limestone produces a crumbly residue called calx—caustic quicklime or calcium oxide. Sprinkled with water, quicklime becomes slaked lime (calcium hydroxide), which generates enough heat to cause spontaneous combustion—and more water feeds the blaze. Theophrastus, a natural philosopher of the fourth century BC, reported that ships laden with cargoes of new togas, which were commonly bleached by brushing them with lime and sulphur, sometimes went down in flames when water splashed on the treated wool. Such accidents were rare, but they would have demonstrated to observers the concept of mixing spontaneously combustible materials for use as weapons.
Sulphur, quicklime, and other substances were combined to make what was known in Latin as pyr automaton, “automatic or self-lighting fire.” The combination was first used to produce pyrotechnic tricks staged by priests and magicians. In 86 BC, for example, the historian Livy watched a religious ceremony in which torches drenched in sulphur, tar, and quicklime continued to burn after being plunged into the Tiber River. Other Latin authors provided recipes for pyr automaton in which sulphur, pitch, quicklime, and naphtha were tightly sealed in containers and then ignited with a single drop of water. Naphtha is the highly flammable light fraction of petroleum, an extremely volatile, strong-smelling, gaseous liquid, common in oil deposits of the Near East. It was the quicklime that caused the mixture to ignite with a drop of water. In the Old Testament, a similar self-lighting fire trick was described as a miracle performed by Elijah to impress the priests of Baal, in about
875 BC.
The potential of combining these substances as an implement of warfare was not realized until much later. A remarkable automatic incendiary weapon, ignited by morning dew, appears in a compilation often attributed to Julius Africanus, a philosopher born in about AD 170 who wrote on magic and military tactics. The recipe calls for sulphur, salt, resin, charcoal, asphalt, and quicklime to be very carefully mixed into a paste during the day, and then tightly sealed in a bronze box, protected from moisture and heat. In the evening, the paste was to be surreptitiously smeared on enemy siege engines. At sunrise, the paste was supposed to combust, ignited by heavy dew or light mist. Such an unpredictable weapon with serious backfire issues was “probably not viewed with favor by military commanders,” commented the British historian of ancient incendiaries, James Riddick Partington, but the elaborate combination of the chemical reactions of sulphur, petroleum, and quicklime hydrated by the natural condensation of dew was one of many experiments that eventually led to the development of complex incendiary weapons.
Perhaps a paste like the one attributed to Julius Africanus could have been used by Medea to turn Princess Glauke’s gown into a murder weapon. By the first century AD, Roman authors familiar with “automatic fire” magic tricks and the destructive properties of petroleum had begun to speculate on Medea’s formula. In his version of the Medea legend, the Stoic philosopher Seneca named “the fire that lurks in sulphur” as one of the components that ignited Glauke’s gown, and he also referred to Medea’s knowledge of “fire-breathing” natural petroleum wells in Asia Minor. Meanwhile, Pliny and the historian Plutarch both concluded that naphtha must have been one of Medea’s secret ingredients.14
The extraordinary conflagration created by Medea, which adhered to the victims’ clothing and skin and burned them alive, has striking similarities to modern napalm. A mixture of a volatile naphtha (or gasoline, another petroleum derivative) and a thickening agent to make it jell, napalm burns at more than five thousand degrees Fahrenheit. Invented in the 1940s at Harvard, napalm was used widely against combatants and civilians by U.S. and South Vietnamese forces in the Vietnam War. One of the most unforgettable images of that war was the 1972 photograph of a naked girl fleeing an aerial napalm attack on South Vietnamese villagers. The jellied, liquid fire consumed her clothes and clung to her body, as she and the other victims ran away in pain and terror. The searing, sticky flames burned down to the bone, and water was of no avail. The ghastly scene could have been written by Euripides 2,500 years ago. Just as the use of napalm was an emotional issue during the Vietnam War and “came to symbolize the horrific nature” of advanced war technologies, so the fate of Glauke burned alive by liquid fire symbolized for the ancients the horrors of nefarious toxic weapons.15
The connection between the fate of the young Vietnamese girl and the Corinthian princess suggests that the myth of Medea was based on arcane knowledge of the destructive burning nature of petroleum. Medea hailed from Colchis, a region between the Black and Caspian Seas known for the rich oil deposits of Baku, where burning gas wells were worshipped as early as the sixth century BC. In antiquity, the Greek name for petroleum—Medean oil—could refer either to Medea or to the land of the Medes (Persia), which also has abundant oil deposits.
Petroleum hydrocarbons come in many forms—all combustible—from the vaporous light fractions and volatile natural gas and liquids like naphtha, to heavier crude oils and tarry bitumen or asphalt. A few rare deposits of petroleum exist in the Mediterranean, but very rich petrochemical resources exist throughout the Middle East (some deposits occur in China and India, too). In the deserts, oily and highly flammable liquid petroleum wells up from the sand and seeps from bedrock (petroleum means “rock-oil” in Latin), and natural gas wells send up cascading flames and burn under water.16
Ancient texts from Mesopotamia show that spontaneously burning lakes and fountains of fire—fire that behaved like water and was unquenched by any liquid—evoked awe from earliest times. Persians, Babylonians, Jews, and other people of the ancient Near East had special reverence for the mystifying phenomena of “liquid fires.” As in Baku by the Caspian Sea, the ancient worshippers in Persia and Babylonia built temples at sites where natural gas wells burned perpetually. For example, the so-called Eternal Fires, a naphtha fountain at Baba Gurgur (near Kirkuk in northern Iraq), had burned continuously since 600 BC before it was tapped by the first modern oil well in Iraq in 1927. Naphtha figured in Jewish religion, too. Elijah’s self-lighting fire was described earlier, and in about 169 BC, Nehemiah gathered a thick liquid from Persia, called nephthar, to create another miraculous self-lighting fire that astounded witnesses. Nehemiah’s trick was analyzed by Partington, who pointed out that spontaneous combustion would occur if naphtha and water were poured over quicklime, or if water was poured onto wood soaked in petroleum and quicklime, or onto sulphur and quicklime. All these components were known and available for experimentation from earliest times. This simple chemical reaction could have produced the effects of Medea’s mythical murderous gown.
FIGURE 37. This burning petroleum fountain at Baba Gurgur (in modern Iraq) has been worshipped since 600 BC.
Archaeological evidence shows that surface deposits of oil in the Near East were exploited—for lamps, torches, pigments, waterproofing, cleaning, magic fire rituals, and weapons—as early as 3000 BC, and evidence from cuneiform tablets and inscriptions indicates that even the dangerously volatile liquids and gases were used. Ancient Assyrian texts indicate that burning petroleum was used to punish criminals, and naft (naphtha) was apparently a siege incendiary in Mesopotamia at an early date, as shown in Assyrian reliefs of flaming firebombs of the ninth century BC.17
It took longer for the early Greeks and Romans to understand the origins and uses of the petroleum of exotic lands. Herodotus was the first Greek historian (about 450 BC) to refer to the awesome powers of the “dark and evil smelling oil the Persians call rhadinace.” Around the same time, Ctesias, the Greek physician who lived in Persia and wrote often garbled accounts of wonders from the strange lands further east, described a curious fire weapon of India. The method of gathering this combustible substance was surrounded by fable, probably to keep it a state secret. Only the king of India was allowed to possess the special oil that derived from giant “worms” lurking in the Indus River, reported Ctesias. The power of the oil was marvelous: “If you want to burn up a man or an animal, just pour some oil over him and at once he is set on fire.” With this weapon, Ctesias heard, the Indian king captures cities without the use of battering rams or siege engines. He simply fills clay vessels with the oil, seals them up, and slings them against the city gates. Upon impact, the oil oozes down and fire pours over the doors. The miraculous oil consumes enemy siege machines and covers the fighting men with fire. Water cannot put it out; the only hope is to smother the flames with dirt.
Apollonius of Tyana, a Greek sage who traveled to India in the first century AD, also heard about something resembling a “white worm” in the River Hyphasis in Punjab that was melted down to render a flammable oil, which could only be kept in glass vessels. Once ignited, it was virtually inextinguishable, and it was the king’s exclusive secret weapon against enemy battlements.
The mystical “worm” oil of India was obviously some form of petroleum, ignited by various means. Other reports about the remarkable effects of liquid fire from the East filtered back to Greece and Italy, but the true sources and ways of controlling the substances remained shrouded in mystery until Roman armies began besieging cities in the Middle East to expand their empire and encountered weapons made from local naphtha.18
Alexander the Great was introduced to the wonders of petroleum “magic” after he captured Babylon in 324 BC. Naft was the most singular of these, wrote Strabo, for “if it is brought near fire it instantly catches fire; and if you pour the liquid on a body and bring a flame near, the person will burst into flames. It is impossible to quench those flames with water, which makes them burn mo
re violently.” The only resort is to suffocate the fire with mud, vinegar, alum and glue, or enormous volumes of water. To impress Alexander, one night his hosts at Ecbatana sprinkled a street with naphtha and set fire to one end—the flames flashed instantaneously to the other end.
Intrigued, Alexander, “for an experiment,” poured some naphtha on a young singer named Stephanus and then brought a lamp near him. Sure enough, the boy was immediately enveloped in flames and would have burned to death, like Glauke in the myth, had not bystanders quickly smothered the fire. Even so, the boy was severely burned.
For Alexander and the Greeks of the fourth century BC, naphtha was an exotic marvel of Babylonia, not a weapon. Although bituminous materials were used in the fire ship at Tyre, no ancient historian recorded the use of petroleum weapons against Alexander in Mesopotamia or India. Recently, however, archaeologists have recovered a bit of evidence indicating that Alexander may have encountered some kinds of incendiary weapons during his campaign in India. At the site of Gandhara (Pakistan), besieged and sacked by Alexander in 327 BC, a strange object was found in the defensive ditch. It was a charred, man-made ball composed of the minerals barite and sulphur, and organic pitch. Its form resembles incendiary balls of bituminous materials found in ancient Mesopotamian sites.
The archaeological team proposed that the sphere was a surviving specimen of fireballs that had been ignited and propelled by slingers at the Macedonian invaders. And indeed, among the incendiary formulas in the Arthashastra, the Indian manual written during the time of Alexander’s invasion, there are instructions for preparing “small balls” to be hurled at the enemy, along with fire arrows. The balls and arrows were made flammable from a paste of powdered plant fibers mixed with resins, dung, charcoal, zinc, “red metals” (perhaps the red mineral realgar, the source of arsenic), lead, and wax. Other Indian recipes for making naphtha arrows and fireballs included magical herbs and ground-up reptiles and worms—as well as the very effective pitch, charcoal, and petroleum. There was even an interesting method of painting the walls of an enemy’s chamber with a mysterious explosive substance—which may have been saltpeter.19
Greek Fire, Poison Arrows, and Scorpion Bombs Page 22
