Volume 59 / Part 2 — GREEK FIRE AND GUNPOWDER.[73]

GREEK FIRE AND GUNPOWDER.[73]

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 Bibliothèque 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 Græcus. 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."

The second sort of flying fire is prepared in this manner:—

"One pound of sulphur vivum, two pounds of charcoal of linden wood or of willow, six pounds of saltpetre, which three things are minutely pounded in a marble mortar. After that you will charge with it a sheath suitable for flying, or for making thunder.

"Note. The sheath for flying ought to be slender and long, and filled with the aforesaid powder well rammed.

"The sheath for making thunder ought to be short and large, and half filled with the aforesaid powder, and well bound in every direction with an iron band.

"Note. That in every sheath a small aperture is to be made, in order that it may be ignited by the match when applied, which match is made slender at the extremities, but in the middle large and filled with the aforesaid powder."

Another receipt of Marcus for Greek fire is as follows:—

"Greek fire is made in the following manner. Take pure sulphur, tartar, sarcocole, (a kind of resin,) pitch, fused saltpetre, and oil of petroleum. Boil them well together. Dip tow in the mixture, and set fire to it. This fire cannot be extinguished but with vinegar or sand."

The close analogy, or rather the identity, of these compositions with gunpowder as at present made, requires no comment. The more important question is the date at which this work was written. This is a matter of great doubt. Messrs Reinaud and Favé, from the fact that the receipt for the preparation of saltpetre to be found in this same book of Marcus is much more imperfect than that in the Arabian MSS., place the date of his book earlier than the thirteenth century. Again, Geber, an oriental writer, the date of whose life is doubtful, but whom our authors fix at the eighth century, has described the preparation of a salt which has been translated nitre, but which our authors consider to have been a sesqui-carbonate of soda, natron, not nitrum. They thence conclude that nitre was unknown to Geber, and thus, because it was known to Marcus, that he lived subsequently; and for this reason they place Marcus between the ninth and twelfth century.

We have seldom seen an instance of more loose deduction than this. It is required to find the date of Marcus. Geber, whose date is unknown, is set down, upon rather weak data, as of the eighth century. Geber's translator is corrected to prove that Geber did not know saltpetre. Hassan Alrammah, an Arabian, is considered as more recent than Marcus, a Greek, because his process for saltpetre is somewhat more perfect; and from the cumulative effect of these data, each of which is very insufficiently established, and which, if established, only go to prove differences in the degrees of perfection of their respective receipts, the date of Marcus is fixed: this certainly is pushing incertum per incertius very far. We fear that if no more accurate information be brought to bear on it, the epoch of Marcus Græcus will be a subject of as much controversy as ever.

The paragraph in the treatises De Mirabilibus of Albert the Great is so identical with that of Marcus Græcus, that there can be no doubt of its being copied from it, or derived from the same source, and is a strong additional instance of the general progress of inventions. A received publication calls attention to a fact already disclosed but forgotten, the knowledge acquired by the world since is brought to bear on the old fact; and a consequent improvement results.

Roger Bacon, to whom the invention or knowledge of gunpowder has been attributed by some, would stand a very poor chance among the men of science of the present day: it is not now the man who conjectures a possibility, but he who demonstrates a fact, that is hailed as the discoverer.

The following series of possibilities are curiously interesting, both from their partial subsequent realization, and from the simple credulity with which Bacon gives us that which he had known "a wise man explicitly excogitate."

"Instruments of navigation can be made, men being the propelling agents, that the largest river and sea barks can be borne along (one man only managing them) with greater speed than if they were full of navigators. Carriages can also be constructed which may be moved without animals, with an inestimable impetus; so that one would think that they were the armed chariots with which they fought in ancient times. Instruments for flying can also be made, so that a man sitting in the centre of the machine, and turning an engine, by which artificial wings may strike the air in the manner of a bird flying. An instrument also can be made, small in magnitude, for elevating and lowering almost infinite weights, than which nothing is more useful in mischances, for by an instrument of the length of three fingers, and of the same breadth or less, a man may extract himself and companions from all danger of prison, and elevate and lower them. An instrument can also be made by which one man may draw to himself a thousand men, by force and against their will. Instruments for walking on the sea can also be made, and in rivers to the bottom without corporal peril. For Alexander the Great used them that he might see the secrets of the sea, according to the relation of Ethicus the astronomer.

"These things, indeed, are of antiquity and of our times, and are certain, except the instrument for flying, which I have not seen, nor have I known a man who has, but I know a wise man who has explicitly excogitated it; and an infinity of other things can be made, as bridges over rivers, can be made without columns or any support, and machines or unheard of engines."

The ultra admirer of the ancients will see in this, if not an accurate relation of facts, which with the exception of the flying it purports to be, at least a wonderful perception of practicabilities; and railroads, diving-bells, suspension-bridges, &c., will be so many circumstantial corroborations of the correctness of his view. We, however, are rather disposed to regard them as ingenious extravagances. Predictions of the success of science are always on the safe side. If in the present day one were to say, that we shall be able to see the inhabitants of Jupiter, or even converse with them, it would be a prophecy which could never be negatived, which might be the case if we said such things were impossible.

Bacon's obscure intimations of gunpowder are not so clearly derived from the same source as the receipts of Marcus Græcus and Albertus Magnus are; but they are apparently derivatives from what was then known to a few, of nitre compositions, and are very analogous, though not quite so extravagant as some of his other deductions.

Bacon also speaks of a child's toy (ludicrum puerile) which was made with saltpetre, the explosion of which produced a report, "quod fortis tonitrui sentiatur excedere rugitum."

As with this, so with the greater number of Bacon's observations; they bear reference to facts, or relations received as facts, which were at that time either generally or partially known, and do not profess to give to the world his own inventions, though the theories deduced from those asserted facts are frequently the produce of his own imaginative brain. Upon the whole, we are fully disposed to agree with Messrs Reinaud and Favé, that the invention of gunpowder is by no means due to Bacon.

We now pass to the Arabian manuscripts of the 13th century, to which we have before alluded, and which constitute the principal discovery of our authors. The same word (baraud) which is now used by the Arabs as signifying gunpowder, was originally used to signify saltpetre; and even in this application had a secondary meaning, its more primitive meaning being "hail." The whiteness and crystalline form of saltpetre presented a sufficient analogy to attach to it a similar name, neology being in those days not quite so common or so easy as at present.

Various salts were also included under the same name, their specific differences not being then known. This fact had probably much influence in retarding the pyrotechnic art, as accurate means of testing the purity and chemical character of the salt were not distinctly understood. A receipt successful in one case, because a proper salt was used, failed in another, because the salt was totally unfit for supporting combustion, though passing under the same name.

In these MSS. occur a vast number of receipts for pyrotechnic compositions, of which we may here give one or two as specimens, and as instances of the close approach made at that time to the composition of gunpowder as manufactured at the present day:—

Proportions of the Sun's Rays. 1st Composition. Saltpetre, 10—Sulphur, 1⅛—Charcoal, 2¼. 2nd Composition. Saltpetre, 10—Sulphur, 1⅞—Charcoal, 2. Proportions of the Garland of Golden Flowers. Saltpetre, 10—Sulphur, 1—Steel filings, ½—Bronze filings, ½. Flashing Rocket. Saltpetre, 10—Sulphur, 1⅜—Charcoal, 2⅛.

Each substance to be separately pounded; the charcoal and saltpetre are then mixed, and gently pounded; moisten with spittle, and then add the sulphur.

White Rocket without sparks. Saltpetre, 10—Sulphur, 1¼—Charcoal, 2¼. To be mixed as before directed. Egyptian Moonshine. Saltpetre, 10—Sulphur, 2¼—Charcoal, ¼. Add 4 parts of Lead or Black Ointment.

These instances will be sufficient to show the general character of the Arabic receipts. Saltpetre is used in all of them—in most of them sulphur or charcoal; while arsenic, incense, camphor, iron and bronze filings, are occasionally used to vary the colour and character of the light produced. The Arabs were also in possession at this period of a vast number of instruments of war in which similar combustible matters were employed, such as lances and clubs, with fires at the extremity, girdles for the waist with fires attached. We translate the description of one of them:—

War Club.

"Get the glass-maker to make a club, which shall be pierced at its extremity like an iron club. Get the turner to turn a stick, which you will fasten strongly to it. You may give it whatever form you please. Arrange on the sides three 'tubulures,' and at the bottom also three for the 'roses,' (one class of the compositions,) then make the usual compositions. When you wish to set fire to them, arrange them in the form of a segment, set fire to the club, and break it, for the love of God."

The termination of this receipt is a very usual one, and applied to several other receipts—instruments of destruction being then, as now, considered a most appropriate method of serving God.

Another ingenious weapon was called "the egg which moves itself and burns;" and this consisted of two long fuses, which seemed to give force and direction to the firework, and a shorter one, which was directed forwards, the object of which was to burn the enemy. This projectile was cast by the hand, and then, to use the quaint language of the receipt, "it walks, it starts, and it burns extremely well."

Many other compositions were known to the Arabs, as appears from the two curious MSS. above mentioned; such as compositions for covering the body to protect from fire, others to emit a suffocating smoke.

The performances of these instruments were, doubtless, what we should now consider very insignificant; but they must have produced upon the excited imagination of the warrior of those days an effect which it is very difficult to conceive in the present day.

Nothing, probably, has occasioned more frequent historical errors, than forming deductions as to real effects from the exaggerated descriptions of ancient writers.

When Musschenbroek (not a superstitious soldier, but an inductive philosopher) first discovered the Leyden Phial, he declared he would not take a second shock for the kingdom of France; and yet we well know that a schoolboy would not now be frightened at a much more powerful shock than he then experienced. Want of familiarity with a phenomenon, and ignorance of its proximate cause, will ever make it terrible. We cannot see any thing terrible in a sky-rocket, because we have been early influenced by those on whom we rely to regard it as an amusement; but had they brought us up in fear of it—had they magnified these accounts, having some foundation in fact, as to its destructive power, we may well understand what effects of terror it would produce.

Thus regarded, the ignotum pro magnifico appears quite sufficient to explain the narrated effects of the Greek fire. But there was also another reason—viz. that all results, not of continual occurrence, and within the range of ordinary experience, were attributed to magic, and consequently spread a terror far disproportioned to the real effects; for this reason, the means of producing then were prohibited by the hierarchy, and, as they gradually acquired a more extensive use, were then only permitted against the enemies of the religion of the people who used them; hence the expression so frequent in the Arabian receipts, "You shall burn your adversary for the service of God;" and similar language is used by the Christian writers, when similar compositions became used by Christian warriors.

A narration, taken from the Sieur Joinville's History of St Louis, will place before our readers the contemporaneous description of the effects of the pyrotechny of the Arabs.

The following is the account of Joinville of one of the skirmishes of St Louis on the borders of the Nile. We should premise that Turk is the term generally applied by Joinville to all Mussulman soldiers; and though the army was generally recruited from Turkish slaves, yet the country was possessed by Arabs, and the language and arts were theirs.

"One evening it happened that the Turks brought an engine called 'la perriere,' a terrible engine for doing mischief, and placed it opposite the 'chaz chateils,' (wooden towers to shelter the advanced guard,) which Messire Gaultier de Carel and I were watching at night, by which engine they cast at us Greek fire, which was the most horrible thing that ever I saw. When the good Chevalier Messire Gualtier, my companion, saw this fire, he exclaimed and said to us, Sirs, we are lost for ever without any remedy; for if they burn our 'chaz chateils' we are broiled and burned, and if we leave our watch we are disgraced. From which I conclude that there is no one can defend us from this peril, except God our blessed Creator. So I counsel you all, that whenever they cast at us the 'feu Grégeois,' that each of us throw himself upon his elbows and knees, and cry mercy to our Lord, in whom is all power; and as soon as the Turcs threw the first charge of fire, we threw ourselves upon elbows and knees, as we had been instructed. And the fire of this first discharge fell between our two 'chaz chateils,' in a space in front which our people had made for damming the river; and immediately the fire was extinguished, by a man whom we had for this purpose. The manner of the Greek fire was such, that it came forth as large as a tun, and the tail extended as long as 'une demye canne de quatre pans.' It made such a noise in approaching, that it seemed like thunder which had fallen from heaven, and seemed to me a great dragon flying through the air; and threw out such a blaze that it appeared as clear as the day, so great a flame of fire was there. Three times during the night they threw this Greek fire at us from the above-mentioned 'perriere,' and four times with the 'arbalesté.' And every time that our good king Saint Loys heard that they thus threw the fire, he cast himself upon the ground, and stretched his hands to heaven, and cried with a loud voice to our Lord, and said, shedding copious tears—'Good Lord Jesus Christ, preserve me and all my people;' and, believe me, his good prayers and orisons did us good service (nous eurent bon mestier)."

It is impossible to render, in literal translation, the quaint simplicity of the old French; but the fact that this terrible fire was extinguished by a single man, would tend very much to lessen our belief in the marvels attributed to it by the narrator.

Be that as it may, we have, in the extract quoted, the expression Greek fire, (feu Grégeois,) which will connect the effect then produced with that known as pertaining to the Greek fire. There is every probability that the compositions here used were the same or similar to those generally known under that title, while the MSS. above quoted detail the compositions used by the Arabs at that period: the evidence is, therefore, very strong that the Greek fire was a composition closely resembling, if not identical with, those indicated in the Arabian receipts.

If we trace back the effects of the combustible compositions to the period of the Crusades, anterior to the time when Joinville wrote, we shall find a strong analogy with those described by him; but the use of saltpetre appears to have been more rare, and that of bituminous substances more frequent.

From an Arabian author of the middle of the 13th century, Casiri translates a passage into Latin, which Reinaud somewhat alters. We render it as nearly as we can in English. "It creeps along with scorpions of nitre powder (baraud) placed in cases. These scorpions take fire, and wherever they fall they burn; they spread abroad like a cloud; they yell like thunder; they burn like a brazier; they reduce all to cinders."

This passage is important, as showing the connexion of nitre or baraud—a word, as we have before stated, applied to nitre and nitre compositions—with a class of effects analogous to those attributed to the Greek fire.

The passage of incendiary compositions into gunpowder is still involved in much obscurity. Messrs Reinaud and Favé consider that a treatise, printed at Paris A.D. 1561, entitled Livre de Cannonerie, throws much light on the subject—"vient de l'éclairer d'une lumière nouvelle;" but we cannot at all agree with them in this view, and for the simple reason, that neither the names of the authors of the receipts contained in it, nor the dates, nor the countries, are given. Without either of these data, our readers, we think, will find it difficult to conceive that much new light can be thrown on the subject. The treatise contains a number of receipts for mixtures of oils, bitumens, sulphur, and nitre; and, as appears to us, all the aid given by this work towards elucidating the subject is, that these receipts are analogous to those of Marcus and of the Arabs, and have some internal evidence of having been written or copied from writings of an early date, though probably subsequent to Marcus; and, secondly the term Greek fire (feu Grégeois) being employed, and receipts for it given, would lead to the inference that the compositions here used under the same title were analogous to those which originally constituted the Greek fire. It is, however, certainly open to the remark, that Greek fire having become, in a great measure, a generic name for violent incendiary compositions, the term may have been applied to compositions analogous in their effects, though of more recent discovery. When, however, we find, in various distinct quarters, similar receipts; when we find these appearing at different epochs, and having different degrees of approximation to the explosive compounds which a more matured experience has rendered certain in their composition, the discovery of such a book as this becomes certainly a corroborative circumstance in favour of that view which regards the Greek fire as never having become extinct, and as having, by progressive but unequal gradations, changed into gunpowder.

In discussing the treatise above mentioned, there is a naïve expression of our authors, who, in remarking the necessary slow combustion of these compounds from the imperfections of the processes of manufacturing saltpetre, also given in the same book, say:—"One sees how much there is that is providential in the progress of human invention. If man had, in the first instance, a powder as strong as at present, he would probably have been unable to master this force, or to use it with suitable instruments, and the discovery would have remained without application. We see that, thanks to the primitive impurity of the saltpetre, man employed mixtures of it with sulphur and charcoal, which produced a force suitable for throwing to short distances feeble parcels of incendiary matter. This force increased little by little, as men became better able to refine saltpetre, and ends by enabling them to employ it for throwing projectiles."

We have frequently heard the word providential applied in a strange manner; but this is one of the most novel views of providential intervention we happen to have met with. The quiet gravity with which Providence is assumed to have interfered in favour of the progress of destructive implements, is about as instructive an instance of the unconscious devotion of an author to his speciality as could easily be selected.

In the treatise of 1561 are some receipts, assumed to be taken from works of an earlier date, in which saltpetre, sulphur, and charcoal, are submitted to a considerable degree of heat. The following is one:—"Take of saltpetre 100 lbs., sulphur, 25 lbs., charcoal, 25 lbs., put them altogether, and make them boil well, until the whole be well united, and then you will thus have a strong powder." Mixed in these proportions, and submitted to such a temperature, the chance of explosion is very great; and, as our authors observe, "the essential fact of the tradition respecting the invention of gunpowder is confirmed;" or rather, strictly speaking, the probability of its truth is strengthened. We therefore do not see very clearly why they should be anxious to divest Schwartz of the merit of its discovery, while they produce arguments to show the probability of the discovery being so made. The results of these arguments would only tend to show that the tradition is not sufficiently explicit, in not stating why the three ingredients were mixed together; and Schwartz would, according to this view, be regarded as the first who remarked and applied, or suggested the application of gunpowder, as supplying an explosive projective force.

Though the probabilities of the use of gunpowder, as an explosive compound, being suggested by accidents occurring in the manufacture of combustible compounds, are thus shown to be very great, the actual step, if step it were, still remains in obscurity. Most probably, like many other inventions, the fact was observed again and again with different degrees of accuracy and different resulting suggestions; until, at length, growing intelligence seized on it, and increasing facility of publication rendered its development more rapid and general. The actual date of its general introduction or use in war is still uncertain. Schwartz's discovery is stated by Kircher at 1354; but gunpowder is stated to have been used at the siege of Stirling in 1339; in Denmark in 1340; in Spain in 1343; at Cressy in 1346; at the siege of Calais in 1347.

Without entering into the critical discussions which the vagueness of the historical records of these periods might tempt, we can scarcely be far wrong in setting down the general introduction of gunpowder during the first half of the fourteenth century, although any attempt to specify, from existing data, the exact date of its invention, would be vain. With regard to its connexion with Greek fire, we may sum up by stating, that during different periods, extending from the eighth to the fourteenth century, combustible matters, in which saltpetre was one ingredient, have been used; and that the term Greek fire has been, at various times within this period, applied to them. Although it does not necessarily follow that the Greek fire alluded to in the more recent works was identical with the Greek fire of an earlier period, yet the probability is strong that there was at least a striking analogy in effect, or the name would not have been used. There is, moreover, some internal evidence of community of origin in these various receipts, when we find that in different parts of the world, in China, in Arabia, and Greece, one general characteristic ingredient is present, viz., nitre; when also the history and progress of chemistry have taught us that no substance, other than nitre or a salt of nitric acid, has ever been, or is now known, which would produce similar effects, (for the comparatively recent discovery of the chlorates would produce effects of detonation by friction or percussion, of which we find no records,) there can, we think, be little doubt that Greek fire was of the same chemical character as gunpowder; that it passed by a transition, which may have been in particular cases more or less sudden, but which upon the whole was gradual, into gunpowder; and that the history of the progress of one of these manufactures is, in fact, the history of the progress of the other. In this history there are still many gaps to be filled up, many errors to be rectified.

The book of Messrs Reinaud and Favé, though somewhat inartificially arranged, has given to the public much valuable information; but there is still room for an elaborate and well-digested treatise on the subject, in which the whole progress of pyrotechnic invention may be arranged in chronological order, and more lucidly expounded than are antiquarian matters in general. This is a task, however, which few, if any, are capable of undertaking, as it requires for its successful execution a combination of extensive antiquarian, chemical, and philological acquirements. In the mean time, our authors may say, and we say with them,