The traditional account of inventions and discoveries whose origin is
involved in the darkness of antiquity is generally short and summary. To
some fortunate individual, whose name, either from his having actually
taken the most prominent part in the progress of the discovery, or, as
is more generally the case, having with the greatest and most
persevering energy impressed it upon the public, the whole merit is
ascribed and the whole glory attached.
The world, active though its individual members be, as to their own
specialties, is inert as a mass, and glad to save itself the trouble of
entering into details by adopting the hypothesis which has been most
urgently forced upon its notice, or which has caught its attention at
one of its most wakeful periods. We thus find nearly every discovery
which has added to the permanent stock of human knowledge attributed to
a single individual, and to a single guess of that individual.
The traditional account of so recent a discovery as that of Galvani, is
the preparation of frog soup for his wife, and the accidental touching
one of them with the knife; while, in fact, he had been for years
employed in examining the convulsive action of frogs, and had presented
several memoirs to the Institute of Bologna on the subject, before its
general publicity; indeed, in the main fact he had been anticipated by
Swammerdam, and he possibly by others.
Schwartz, the monk of Cologne, probably had a real existence, probably
had something to do with the progress of pyrotechnic art; it is even
more probable that he invented gunpowder than that the public invented
him. The very accident which is reported to have happened, it is not
altogether improbable did happen; but if a mixture of saltpetre,
sulphur, and charcoal accidentally exploded, it was not accident which
brought together those particular three ingredients out of the whole
laboratory of nature and art.
It is indeed possible that the frequency of accidental explosions when
gunpowder was known, were reflected back as a plausible hypothesis to
account for its invention; but as the explosive power and utility of
gunpowder were not facts which could have been arrived at by _a priori_
reasoning, there is every likelihood of such an accident having
originally suggested the application of an explosive mixture as a means
of propulsion. The history of the invention then resolves itself into
the question, Were any admixtures of these three ingredients previously
known, what led to them, and what were the objects proposed by them?
This question is attempted to be answered by the book before us,
containing a very erudite inquiry into the progress of the invention of
Greek fire and gunpowder, which are, according to the author's view,
modifications of the same thing, _i.e._ pyrotechnic compositions,
differing only or mainly in the proportions or purity of their
ingredients. A mass of very curious information is given to the reader,
which, in addition to the general stock of knowledge or obscure
tradition on this subject, shows a gradual and generally diffused use of
sulphur, saltpetre, and charcoal in different proportions, and
occasionally mixed with other combustible substances. Among the Arabs of
the thirteenth century a vast number of receipts for such mixtures
existed; this is proved by some ancient Arabic MSS. preserved in the
Bibliotheque Royale. How the Arabs got possession of these arts is left
somewhat in obscurity, though our authors consider there are strong
grounds for conjecturing that they obtained then originally from the
Chinese about the ninth century; that they then proceeded slowly in
improving this knowledge for the three centuries during which they had
no intercourse with the Chinese; and that they again acquired further
information on these points after the Mongul irruption in the thirteenth
century.
The defect of the book before us is its inconclusiveness: from the
preface we are led to expect the solution of a theorem; after reading
the book through, we find ourselves not indeed as far at sea as ever,
but aided mainly by negations. The actual origin of gunpowder or Greek
fire is not traced; many of the connecting links in the chain of
pyrotechnic discovery are still deficient; and the conjectures, which
stand in the place of conclusions, are frequently founded upon what
appear to us insufficient data. On the other hand it must be admitted,
that on a subject so involved in obscurity, inasmuch as proof is
impossible, speculation is to a certain extent admissible as a link to
render isolated facts intelligible.
It may be well here if, before passing to the more immediate object of
this paper--viz. a sketch of the probable progress of pyrotechny--we
explain to those of our readers who are unacquainted with chemistry, the
philosophy of explosive combustibles.
Combustion is nothing else than rapid chemical union, taking place
between two dissimilar substances, which have what is called an affinity
for each other, _i.e._ a tendency to unite and form a new compound. When
a candle or lamp is burned, it is carbon and hydrogen, the principal
constituents of oil or fat, which combine with oxygen, one main
ingredient of the atmosphere. As it requires a certain temperature for
this union to take place, to prevent the cooling effect of mass, a wick
is used which can be readily heated, and where, as soon as chemical
action has once taken place, other portions of the oil or melted tallow
are absorbed, which ascend just as water through the pores of a sponge,
and supply the place of those burned. In this example, only a small
ignited surface is exposed to the influence of the oxygen: if, however,
this latter element could be obtained in a solid state, and mixed up
with the combustible, each particle throughout the whole mass would have
in contact with it a particle of oxygen; so that, if the whole were
raised to the necessary temperature for combustion, combustion would be
instantaneous--or if the temperature of a part were sufficiently
elevated, the combustion of this portion would communicate an intense
heat to the contiguous portions, and the whole would rapidly kindle as a
fuse does. In this case also, the access of the air being immaterial,
combustion might take place in a closed vessel, or even under water.
Nitre, or saltpetre, is one of a class of substances which contains a
large portion of oxygen in a combined and solid state; and, being mixed
with combustible matter such as charcoal, it causes rapid deflagration
when the temperature is raised. The whole class of pyrotechnic
compositions are reducible to this simple principle--they all consist of
combustible substances intimately mixed with substances containing
oxygen; or, to reduce the proposition to more general and simple terms,
they consist of two or more substances, having for each other a powerful
chemical affinity, and capable of rapidly uniting when the temperature
is elevated. When a projectile force is necessary, a further condition
is essential, viz., that they liberate by their chemical action gaseous
matter, whereby a sudden increase in volume is produced, the expansion
of which, augmented by the high temperature, produces the required
effect of propulsion.
This slight sketch will show that the purity and proportions of the
saltpetre, and the inflammable substances mixed with it, are the main
elements to be attended to in the improvement of self-burning
compositions: it is indeed far from improbable, that the substances used
in purifying saltpetre have first suggested such compounds. Wood ashes
were used at a very early period for purifying nitre; and at the end of
an Arabic receipt of the thirteenth century, for the preparation of
saltpetre, in which charcoal is used, is the expression, "guard against
sparks of fire."
The probabilities strongly favour the view, that incendiary compositions
of the nature we have been describing originated with the Chinese. China
snow, and China salt, are the names given by writers of the greatest
antiquity to saltpetre. In the Arabic MSS. to which we shall presently
allude, the words Chinese wheel, Chinese flower, Chinese dart, occur as
appellatives of different fireworks. It is very possible that the influx
of Chinese literature, which the result of the recent war with that
people promises us, will lead to the discovery of Chinese treatises upon
pyrotechny.
Other authors speak of fire-arms among the Chinese at a very early
period of our era, and even before Christ; but the interpretation which
they have put upon obscure passages--interpretations evidently derived
from their existing knowledge--makes these expressions and translations
of extremely doubtful import.
At a later period, however, we have the authority of Raschideddin,
(minister of the Tartar Khan of Persia,) and of Marco Polo, that the
machines of war employed at the siege of Siang Yang were constructed by
Arabian or European workmen, and that the Tartars were not at this
period themselves able to manufacture such machines. This would tend to
negative the belief which has been entertained by some, that the Chinese
then used gunpowder as a means of projection, but does not lessen the
possibility that the fuses and compositions projected by these machines
were of Chinese origin.
In the history of the dynasty of Sang, A.D. 1259, there is a distinct
account of a projectile by means of fire as follows:--"In the first year
of the period _Khaiking_, a kind of arms was manufactured called
_Tho-ho-tsiary_, that is to say, 'impetuous fire-lance.' A nest of
grains was introduced into a long tube of bamboo, to which fire was set.
A violent flame darted forth, and instantly the nest of grains was
projected with a noise similar to that of a peacock, which was heard at
a distance of about 150 paces."
Upon the whole, it would appear that the Chinese, although the character
of their claims to the knowledge of gunpowder has been exaggerated, were
in all probability the people among whom mixtures of combustibles with
oxygenated substances originated; and this will form one of the many
interesting fields of inquiry to be pursued by those skilled in the
literature of the Chinese, now that the field is so largely opened to
them.
There are obscure passages in writers of a very early period, which
speak of thunderbolts being shot from the walls of besieged towns upon
the enemy. Philostratus speaks of such; but the indefinite character of
these expressions makes their connexion with either Greek fire or
gunpowder extremely doubtful.
In the year 883, Nicetas, admiral of the Eastern empire, was sent by the
Saracens of Crete to assault Constantinople, and is stated to have
burned twenty of their ships with Greek fire.
One of the earliest accounts of its composition is that given by Anna
Comnena, who states it was composed of sulphur, bitumen, and naphtha;
but the most distinct early receipt for a composition analogous to
gunpowder, is that contained in the celebrated book of Marcus Graecus. In
the book called _Liber Ignium_, we have the following receipts:--
"Note. That the fire capable of flying in the air is of twofold
composition, of which the first is: One part of colophon and an equal
part of sulphur, two parts of saltpetre, and well pulverized, to be
dissolved in linseed or laurel oil. A case, or hollowed wood, is then to
be charged with it, and ignited. It will fly suddenly to whatever place
you wish, and burn up every thing by its fire."