Index Home About Blog
Newsgroups: rec.pyrotechnics
From: (Roger Fleming)
Subject: Re: Greek fire
Date: Mon, 09 Oct 2000 13:35:48 GMT wrote:
>The composition of Greek fire is lost to history.

Certainly true. But it's fun to speculate!
>I suspect the stuff was nothing more than a petroleum compound made
>from naturally occurring crude oil, and maybe pitch.  I don't know if
>the Byzantines could distill,

No they did not have distillation. However until the invention of distillation
(and subsequent discovery of ethanol and turpentine) naphtha (a natural light
petroleum fraction) was the only known flammable liquid at room temperature,
so almost certainly petroleum was included somewhere.[...]

>The composition does not need to be spontaneously inflammable to be
>effective.  [...]

That's the trouble though. The various bizarre ingredients historians have
speculated about were attempts to explain specific properties that were
reported by numerous observers, separately over a period of centuries. And one
of those properties was spontaneous flammability.
Specifically, the stuff was said to:
- burn on water (easy, naphtha does that);
- be impossible to extinguish (hence speculation of an oxidiser, you suggest
they mean "impossible to extinguish with water")
- ignite spontaneously (ridiculous speculation that quicklime would cause this
on contact with water, you suggest a simple exaggeration).

Now I agree that saltpetre and quicklime are rubbish because
1. Neither dissolves in naphtha, hence they would sit uselessly at the bottom
of the siphonida fuel tank; and
2. Although quicklime gets very hot in contact with water, it isn't nearly hot
enough to cause ignition.

Also, if you look in more detail at specific claims about it's properties,
they aren't quite so easily dismissed:
@Nonextinguishability: it is specifically claimed that _nothing_ coould
extinguish it, even on land, _except_ for another secret recipe. For example,
in n account of the landing of crusaders at Damietta, it is said that Greek
fire, used by the townsfolk but turned against them by the wind, was only
extinguished by some slaves who were in possession of the secret method of
extinguishing it.
@Spontaneous flammability: it is said not simply to have been spontaneously
flammable, but specifically, to ignite from shock (a clay vessel being smashed
open, or a hidden clay vessel run over by a wagon), from contact with water,
or sometimes spontaneously in the air, but only on very hot days. Its
safe transportation was restricted to airtight copper vessels.
@Fumes: its combustion is said to have been noxious, leading some historians
to add sulphur to their speculative mix. Yet it _wasn't_ described as
sulphurous, surely a reasonably familiar odour at a time when brinstone was
regularly burned around the carnage of battlefields.
@Complexity: since the preparation remained a secret for nearly eight
centuries, then was completely lost _after_ transmission to other peoples -
all despite the fact the Arabs had much readier access to naphtha - suggest
the preparation was quite esoteric.

<CRAZY SPECULATION> If I was asked, without reference to any specific era, to
name a material that mixes with naphtha, that ignites spontaneously on hot
days or with modest friction on cool ones, that burns with noxious but not
sulphurous fumes, and that is nearly impossible to extinguish without special
chemicals, I would not hesitate to mention white phosphorus. This is
preposterous of course; phosphorus was not known in the ancient world, being
discovered only in the seventeenth century. But is it so unreasonable to
speculate that Callinicus may have stumbled on P 1000 years before Brand? The
process is, after all, only moderately complex, hardly enough to daunt even a
seventh century alchemist. Furthermore, if done in the "natural" and "obvious"
way, (missing the element of distillation which the Byzantines didn't have,
remember), the product will be heavily contaminated by calcium phosphide,
thereby avoiding a premature discovery of pure phosphorus, and adding the one
missing property of Greek Fire - spontaneous ignition in water. Oh, and the
secret ingredient for extinguishing the fire is any soluble copper salt (eg
they certainly had copper acetate) plus something to smother the naphtha
(sand, soapy water, whatever). </CRAZY SPECULATION>
I don't claim this with too much seriousness, but I've several times noticed
it seems to fit the known facts a lot better than the standard theories.

Index Home About Blog