The Chemistry of Greek Fire


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Although the Western Roman Empire had collapsed centuries earlier, the Eastern half, more commonly known as the Byzantine Empire, continued to thrive from the city of Constantinople. One of the reasons for this success was a naval superweapon perfected by the Greek architect, engineer, alchemist, and inventor Kallinikos. Known as Greek Fire, Sea Fire, Liquid Fire, and various other names, the recipe was such as closely guarded secret of the Empire that eventually the Byzantines realized that no one remembered how to make it. Soon after, the Byzantine Empire collapsed since its formerly invincible Navy lost their most potent weapon. To this day, no one knows exactly how Greek Fire was made, although some of Kallinikos’s partially-complete notes have been found. Due to some inconsistencies in the notes, as well as conflicting accounts on its method of delivery, there are three conflicting theories on the composition.

I chose Greek Fire because of its incredibly important role in the rise of one of history’s greatest empires. Also, I’ve always wanted to make an incendiary weapon but stay safe at the same time. Therefore, I chose Greek Fire as my experimental subject.

I love researching chemistry, and Greek Fire has always fascinated me for one reason or another. So while the mixture doesn’t directly affect my life at the moment, history may have taken a very different course if Kallinikos had never invented it. I might not have ever been born, so I guess it’s pretty important to me.

Composition of ...

Since there are three different theories regarding the composition of Greek Fire, it is necessary to test all three of them and list their compositions as well.

Theory One- “Gunpowder”

75% Potassium Nitrate- KNO3

15% Carbon- C

10% Sulfur- S8

Theory Two- “ANFO”

94.3% Ammonium Nitrate- NH4NO3

5.7% Hydrocarbons- Various formulas, all composed of only Hydrogen and Carbon. Average C12H23.

Theory Three- “Napalm”

Pentane- C5H12

Hexane- C6H14

Octane- C8H18

Pinene- C10H16

Sulfur- S8

Calcium Oxide- CaO

Chemistry's Role

Like the formulas, explaining the chemical reactions taking place requires three separate explanations; one for each theory. However, they all have one thing in common: Combustion. Colloquially known as “Fire,” Combustion is the underlying process in all of the different formulas. Three parts are necessary for combustion to occur: Oxygen, Fuel, and Heat. 

Theory One- “Gunpowder”

10KNO3 + 8S+ 3C → 2KCO3 + 3K2SO4 + 6CO2 + 5N2

Potassium Nitrate provides the oxygen. Sulfur and Carbon are fuels. The heat source can vary, although most commonly it is provided by friction or an already-lit flame or spark. The products are Potassium Sulfate, Carbon Dioxide, and Nitrogen gas.

Theory Two- “ANFO”

30 C8H18 + 160 NH4NO3 160 N2 + 59 H20 + 240 CO2

Ammonium Nitrate acts as an oxidizer. The fuel is provided by hydrocarbons such as Octane in the above reaction. Again, the heat source can vary. The products are Nitrogen gas, Hydrogen gas, and Carbon Dioxide.

Theory Three- “Napalm”

There is no single chemical reaction for this formula because the ratios and composition can vary so greatly. However, the job each chemical performs is the same every time. The Calcium Oxide acts as both an oxidizer and a heat source since it reacts exothermically with water to produce Calcium Hydroxide. The fuels are the hydrocarbons and the sulfur. Pine rosin is would have been added as a thickener, but it does not affect the reaction besides being an additional fuel.

Background Research

Composition probably included a mixture of quicklime, saltpeter, naphtha, sulfur, resin, and pitch, and calcium phosphide. Some form of bitumen, such as tar or asphalt, was likely used as a base. No one knows the exact composition and there are conflicting accounts as to its properties.

Little is known about Greek Fire because it was such a closely guarded secret; eventually the Byzantine Empire realised no one remembered how to make it!

It was projected from the bow of a ship in a special tube called a siphon.

A Greek alchemist and inventor named Kallinikos is commonly cited as the one who created the incendiary mixture. Although the stuff had been invented long before him, it was probably Kallinkos who perfected the mixture and discovered how to effectively weaponize it. Most importantly, he discovered how to make it inextinguishable by water. In fact, Kallinikos’s mixture produced flames that grew when exposed to dihydrogen monoxide.

Byzantine ships were coated in a mixture of vinegar, alum and talc to be fire resistant since the mixture did not differentiate between the Greek ships and their enemies. The stuff could also be used as type of early grenade. Sealed ceramic pots filled with Greek fire on one side and water in a separate compartment and thrown at enemies. The water and Greek fire would mix when the pot smashed and would combust.

It was essentially a precursor to modern napalm. One of the major reason the Byzantine Empire lasted for as long as it did. The Arabs created their own version of the mixture, and although it was not nearly as potent as the original, it still proved a deadly force on the battlefield.

In warfare, Greek Fire turned out to be just as effective from a morale standpoint as it was tactically. Since it burned on water, the Byzantines’ enemies were terrified of the mixture. It proved to be the deciding force in many Byzantine naval battles.

About the Author
Giancarlo Barbera is a senior at Billings Senior High School. He is fascinated by weaponry in all its forms, even though he is not a violent person. He is a martial artist with training in Krav Maga, Pencak Silat, Brazilian Jiu Jitsu, and Combat Hapkido. He has a very high IQ but very poor social skills. He also enjoys Debate.