Читать книгу Gunpowder and Ammunition, Their Origin and Progress - H. W. L. Hime - Страница 8

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The attention of the ancients was naturally attracted by the efflorescences which form on certain stones, on walls, and in caves and cellars; and the Hindus and nomad Arabs must have noticed the deflagration of at least one of them when a fire was lit on it. These efflorescences consist of various salts,—sulphate and carbonate of soda, chloride of sodium, saltpetre, &c.—but they are so similar in appearance and taste, the only two criteria known in primitive times,19 that early observers succeeded in discriminating only one of them, common salt, from the rest. So close, in fact, is the resemblance between potash and soda, that their radical difference was only finally established by Du Hamel in 1736. Common salt received a distinctive name in remote times; all other salts were grouped together under such vague generic names as nitrum, natron, afro-nitron, &c.

No trace of saltpetre has hitherto been found anywhere before the thirteenth century. The Greek alchemists of preceding centuries are silent. There is no saltpetre in the earliest recipe we possess for Greek fire, No. 26 of the Liber Ignium,20 ascribed to one Marcus Græcus, either as given in the Paris MSS. of 1300, or in the Munich MS. of 1438. It is true that the phrase sal coctus in this recipe has been translated by saltpetre in M. Hœfer’s untrustworthy Histoire de la Chimie, but as MM. Reinaud and Favé remark: “Rien n’autorise à traduire ainsi; le sel ordinaire a été souvent employé dans les artifices.”21 There is no instance in Latin, I believe, of saltpetre being designated otherwise than by sal petræ (or petrosus), or by nitrum, singly or in combination with some other word, as spuma nitri. The substitution of sal petræ for sal coctus, in later editions of the recipe, only shows that when the valuable properties of saltpetre became known it was employed instead of common salt. The very fact of the change having been made by most of the later alchemists, proves that to them sal coctus did not mean sal petræ, but something else. If sal coctus had meant sal petræ, what need was there for the change? This change, however, was not universal. In the version of recipe 26, given in the Livre de Canonnerie et Artifice de Feu, published in Paris in 1561, but written long before by a fire-worker well acquainted with saltpetre, we find: “prenez soufre vif, tarte, farcocoly (sarcocolla), peghel (pitch), sarcosti (sal coctum), &c.”22 The word coquo (to boil or evaporate) was necessarily connected with the preparation of common salt by evaporation,23 and coctus would correctly distinguish evaporated or artificial salt from natural or rock salt. In his “Natural History,” xxxi. 39 (7), Pliny tells us that salt is found round the edges of certain lakes in Sicily which are partially dried up in summer by the heat of the sun; while in Phrygia, where much greater evaporation takes place (ubi largius coquitur), a lake is dried up (and salt is deposited) to its very middle. Sal coctus was salt recovered from salt water by natural or artificial heat, as distinguished from natural, or rock salt, which was dug out of the ground.24

The Arab alchemists before the thirteenth century are as silent as the Greeks: nothing that can be identified with saltpetre is to be found in their voluminous works. The evidence of Geber, so often cited to prove that saltpetre was known to the Arabs in the ninth century, has been stripped of all authority by M. Berthelot, who has satisfactorily proved that there were two Gebers. The real Arab, Jabir, says nothing of saltpetre, but he mentions a salve used by naphtha-throwers25 as a safeguard against burns. The other Geber, or pseudo-Jabir, was acquainted with saltpetre, as well he might be; for he was a western who lived some time about the year 1300,26 and wrote a number of Latin works falsely purporting to be translations from the Arabic of the real Jabir. All doubt about the matter has been removed by M. Berthelot’s publication of the real Jabir’s Arabic writings.27 It has been also suspected that the sal Indicus of the Liber Sacerdotum, cir. tenth century,28 a salt again mentioned in the Liber Secretorum of Bubacar, cir. 1000,29 means saltpetre. Both these works are translations from the Arabic or Persian,30 and sal Indicus is the literal translation of the Persian—نمك هندي (nimaki Hindi) = نمك سياه (nimaki siyah) = salt of bitumen; a substance of the same family as the “salt of naphtha” also mentioned by Bubacar.

There is no word for saltpetre in classical Sanskrit, sauverchala being a generic term for natural salts, which corresponded to, and was as comprehensive as the nitrum, spuma nitri, &c., of the West. “Recent Sanskrit formulæ for the preparation of mineral acids containing nitre, mention this salt under the name of soraka. This word, however, is not met with in any Sanskrit dictionary, and is evidently Sanskritised from the vernacular sora, a term of foreign origin.”31 Both Professor H. H. Wilson and Professor M. Williams, in their Sanskrit dictionaries, “erroneously render yavakshara as saltpetre, as also does Colebrooke in his ‘Amara-kosha.’”32 The word means impure carbonate of potash obtained by the incineration of barley straw.33

At length, however, notwithstanding coarse scales and clumsy apparatus, the want of all means of registering time and temperature, and the absence of any general principle to guide them in their researches, the alchemists succeeded in differentiating certain natural salts from the rest, and among them saltpetre. The Chinese were acquainted with it about the middle of the thirteenth century.34 Abd Allah ibn al-Baythar, who died at Damascus in 1248, tells us that the flower of the stone of Assos was called Chinese snow by the Egyptian physicians and barūd (i.e. saltpetre) by the (Arab) people of the West.35 Friar Bacon, whose De Secretis was written before 1249, and Hassan er-Rammah who wrote 1275-95, were thoroughly acquainted with the salt. A grand chemical discovery had been made, and saltpetre became known from China to Spain.

The Egyptians thought fit to call saltpetre “Chinese snow,” but this does not justify the conclusion that the discovery was made by the Chinese. Consider our own phrases “Jerusalem” artichoke, “Welsh” onion, and “Turkey” cock. Jerusalem is a gardener’s corruption of girasole, the Turkey came from America, and the home of the Welsh onion is Siberia. The Persians called their native alkaline salt jamadi Chini, and no one will suggest that this substance came from China.

It is evident from the way in which it is mentioned by the alchemists of the thirteenth century, and from their primitive methods of refining it, that saltpetre was then in its infancy. Roger Bacon speaks of it as one would speak of a substance recently discovered and still little known—“that salt which is called saltpetre” (illius salis qui sal petræ vocatur).36 Marcus Græcus thought it necessary to explain what the word means, in his 14th recipe which probably belongs to the latter years of the thirteenth century.37 The methods of refining the salt given by Marcus and Hassan leave no possible doubt that in their time it had but just come into use. It is true that Bacon’s method was much superior, if the solution of his steganogram given in Chap. viii. be accepted. But it would have been past all explanation had the method of the greatest natural philosopher of the age been found to be no better than that of an Arabic druggist or a European fireworker.

As the matter is one of the greatest importance, the methods of all three are given in full, together with that of Whitehorne, 1560. The Waltham Abbey method is added, as a standard by which to judge them. To admit of easy comparison, the corresponding operations are marked with the same letter. The five methods are summed up in Table I.