Attfield, John. (1873) Chemistry, general, medical, and pharmaceutical.
NITRIC ACID AND OTHER NITRATES.
Formula of Nitric Acid HNO3. Molecular weight 63. Introduction.-The group of elements represented by the formula NO3 is that characteristic of nitric acid and all other nitrates; hence it is expedient to regard these elements as forming an acidulous radical, which may be termed the nitric radical. Like the hypothetical basylous radical ammonium (NH4), this supposed acidulous radical (NO:) has not been isolated. Possibly it is liberated when chlorine is brought into contact with nitrate of silver; but if so, its decomposition into white crystalline nitric anhydride (N205) and oxygen (O) is too rapid to admit of its identification.
Sources.-The nitrogen and oxygen of the air combine and ultimately form nitric acid whenever a current of electricity (as in the occurrence of lightning) passes. Nitrates are commonly met with in waters, soils, and the juices of plants. In the concentrated plant juices termed medicinal ” Extracts,” small prismatic crystals of nirate of potassium may occasionally be observed. (The cubical crystals often met with on extracts are chloride of potassium.) Nitric acid and other nitrates are obtained from nitrates of potassium and sodium, and these from the surface soil of tropical countries. Nitrate of potassium or prismatic nitre (from the form of its crystals) is chiefly produced in and about the villages of India. The natives simply scrape the surface of waste grounds, mud heaps, banks, and other spots where a slight incrustation indicates the presence of appreciable quantities of nitre, mix the scrapings with wood-ashes (carbonate of potassium, to decompose the nitrate of calcium always present), digest the mixture in water, and evaporate the liquor. The impure product is purified by careful recrystallizations, and is sent into commerce in the form of white crystalline masses or fragments of striated six-sided prisms. Besides its use in medicine (Potassii Nitras, U. S. P.), it is employed in very large quantities in the manufacture of gunpowder. Nitrate of Sodium (Sodii Nitras, U. S. P.) occurs in more distinct incrustations on the surface of the ground in Peru, Bolivia, and Chili, more especially in the district of Atacama; it is distinguished as Chili saltpetre or (from the form of its crystals-obtuse rhomboids) cubic nitre, and is chiefly used as a manure and as a source of nitric acid, its tendency to absorb moisture unfitting it for use in gunpowder. In many parts of Europe nitrate of potassium is made artificially by exposing heaps of animal manure, refuse, ashes, and soil to the action of the air and the heat of the sun: in the course of a year or two the nitrogen of the animal matter becomes oxidized to nitrates, and the latter are removed by washing.
The word nitric is from nitre, the English equivalent of the Greek vatpov (nitron), a name applied to certain natural deposits of natron (carbonate of sodium), for which nitrate of potassium seems at first to have been mistaken. Saltpetre is simply sal petrce, salt of the rock, in allusion to the natural origin of nitrate of potassium. Sal prunella (from sal, a salt, and pruna, a live coal) is nitrate of potassium melted over a fire and cast into cakes or bullets.
Chemical nomenclature has been modernized to the extent of defining the alkali-metal and earthy salts as those of potassium, sodium, ammonium, barium, calcium, magnesium, and aluminium, instead of potash, soda, ammonia, baryta, lime, magnesia, and alumina. The author confidektly believes that this change, founded on views now adopted by all prominent writers on chemistry, and used in the Pharmacopoeia of the United States, will be accepted and become popular with pharmacists; it is a step in the direction of simplicity and consistency, and involves far less hypothesis than is contained in the old system. The name nitrate of potash, for example, was based on the pure assumption that nitre contained oxide of potassium or potash and nitric anhydride, then erroneously termed acid. By the modern name nitrate of potassium, all that is intended to be conveyed is that nitre contains the element common to all potassium compounds, and the group of elements common to all nitrates. Under the old method, students always experienced difficulty in distinguishing salts of the metal from salts of its oxide —salts of potassium, for instance, fiom salts of potaslih; under the new view no stuch difficulty arises. Names such as potassium nitrate or potassic nitrate are also consistent with modern views, but for general adoption are too unlike the original. The contractions in Latin for names like “nitrate of potassium” are identical with those names resembling ” nitrate of potash;” an accidental circumstance that will much facilitate the general introduction of the former among medical practitioners and pharmacists, and a practical advantage that must determine the choice over the other chemically equivalent names just mentioned. The author ventures to express his extreme gratification at the adoption of this system of nomenclature in the recently published Pharmacopoeia of the United States (1873).
Nitrogen……….. N From vz-pov (nitron), and i~vE-r, (genesis), generator of nitre.
Deflagration means violent burning, from flagratus, burnt (flagro, I burn), and de. a prefix augmenting the sense of the word to which it may be attached. Paper thrown into a fire simply burns, nitre deflagrates. De-tonate (detono) is a precisely similar word, meaning to explode with violent noise.
SALTS OF ACIDULOUS RADICALS. ” sulphate of potassium,” is in this respect no better. Secondly, it is impracticable to study salts as a whole. Teachers are unanimous in the opinion that students should first master the reactions characteristic of the metals in salts, and then the residues which, with those metals, make up the salts, or vice versad. It is not only impracticable, but impossible, to study salts as a whole; binary ideas concerning them are therefore almost inevitably imbibed. We come to regard a salt as a body which splits up in one direction only, look upon nitre, for instance, and all other nitrates, as containing NO: and a metal, K; whereas KNO3 may be split up into KNO2 and 0; or into K2O, N2, and 05; or may contain K2O and N2O5. These are the chief disadvantages attending the employment of the binary hypothesis in studying chemical’ compounds: if they be borne in mind, the hypothesis may be freely used without much danger of permanent mental bias. Thus in nitre let the group of elements (NO3) which, with potassium, makes up the whole salt be called the nitric radical, the name of the latter being directly derived from its hydrogen salt. Similarly allow the acidulous residues of other salts of metals to be termed respectively the chloric, acetic, sulphurous, sulphuric, carbonic, oxalic, tartaric, phosphoric, citric, boracic radicals. In short, these compound radicals should be regarded as groupings common to many salts, and which may usually be transferred without any apparent breaking or splitting; at the same time we must be prepared to find that occasionally a salt divides in other directions. In this way perhaps erroneous impressions will gain least hold on the mind, and a way be left open for the easy entrance of new truths, should the real constitution of salts be discovered. Formerly salts (such as sulphate of magnesium) were regarded as containing (a) an oxide of a metal (MgO) and an anhydride (SO3), the latter being incorrectly called an acid (sulphuric acid). or (b) as containing two simple radicals (e. g. KI, NaC1l, KCy, HgS)-the former being called oxyacid salts, or ox.ysalts, and the latter haloid salts (from axe, als, seasalt, and E18o, eidos, likeness). Such distinction is no longer maintained, the two classes being merged. This is an important educational gain on the side of simplicity; for, whereas under the old system much time was necessarily expended before salts of a metal and salts of the oxide of that metal could be distinguished (e. g. KI and MgO,S03), now, all salts being regarded as salts of the metals themselves (e. g. KI and MgSO4), no such distinction is necessary.
Samon, W (MD). (1681) Doron Medicum; or, a Supplement to the New London Dispensatory, etc
154. Sal Prunellae – Salt of Harts-hord
155. Sal Prunellae – Salt of Vipers
156. Sal Prunellae – Salt of Harts-horn, Volatile Salt of Amber
157. Sal Prunellae – Salt of Soot, Volatime Salt Armoniac
158. Sal Prunellae – Bezoar Minerale. Flowers of Sal Armniac
159. Sal Prunellae – Seruse of Antimony.
Medical Explanations
336. Sal Prunellae, Salt-Peter or Niter purified with brimstone.
On Nitre: Nitre is the flame by which all subliminary fire is kindled and sustained, that by which all plants do grow and flourish, and by which all living creatures live and breath.
The History of Chemistry by Thomas Thomson, M.D. F.R.S.E. Professor of Chemistry in the University of Glasgow. In Two Volumes. Vol. I. London: Henry Colburn, and Richard Bently, New Burlington Street. 1830. Whiting, Beaufort House, Strand.
Asphalt was one of the great constituents of the Greek fire. A great bed of it still existing in Albania, supplied the Greeks with this substance. Concerning the nature of the Greek fire, it is clear that many exaggerated and even fabulous statements have been published. The obvious intention of the Greeks being, probably, to make their invention as much dreaded as possible by their enemies. Nitre was undoubtedly one of the most important of its constituents; though no allusion whatever is ever made. We do not know when nitrate of potash, the nitre of the moderns, became known in Europe. It was discovered in the east; and was undoubtedly known in China and India before the commencement of the Christian era. The property of nitre, as a supporter of combustion, could not have remained long unknown after the discovery of the salt. The first person who threw a piece of it upon a red-hot coal would observe it. Accordingly we find that its use in fireworks was known very early in China and India; though its prodigious expansive power, by which it propels bullets with so great and destructive velocity, is a European invention, posterior to the time of Roger Bacon.
The word nitre (רתנ) had been applied by the ancients to carbonate of soda, a production of Egypt, where it is still formed from sea-water, by some unknown process of nature in the marshes near Alexandria. This is evident, not merely from the account given of it by Dioscorides and Pliny; for the following passage, from the Old Testament, shows that it had the same meaning among the Jews: “As he that taketh away a garment in cold weather, is as vinegar upon nitre: so is he that singeth songs to a heavy heart.”100 Vinegar poured upon saltpetre produces no sensible effect whatever, but when poured upon carbonate of soda, it occasions an effervescence. When saltpetre came to be imported to Europe, it was natural to give it the same name as that applied to carbonate of soda, to which both in taste and appearance it bore some faint resemblance. Saltpetre possessing much more striking properties than carbonate of soda much more attention was drawn to it, and it gradually fixed upon itself the term nitre, at first applied to a different salt. When this change of nomenclature took place does not appear; but it was completed before the time of Roger Bacon, who always applies the term nitrum to our nitrate of potash and never to carbonate of soda.
Chapter 12.01: Mild-Cured Bacon
Not only was it prescribed for ailments throughout history, but 30 years following the invention, we find this advertisement for Sal Prulenna in England from a magazine. The following report appeared in the Chemist and Druggist of 1859. It is for “Sal Prunella Tabloids.” and reads, ” A popular remedy, sometimes successful in mild cases of incipient inflammatory sore throat, is a small piece of nitre allowed to dissolve slowly in the mouth” (Warning: “An excellent saline for throat cases, having very marked local efficacy when slowly dissolved on the tongue. It is a popular remedy, and for mild inflamed sore throats its ancient reputation is deserved. Directions One or more (5gr) Tabloids should be slowly dissolved in the mouth for the local effect. Supplied in bottles of 100 at 14/ per doz. Retail price, 1/6.”
That it has antiseptic properties must have been known or suspected, and that the properties “emerge” and is not immediately present could very well have been suspected for many years.
The manufacturing is described in an 1835 publication as “Sal prunella (from sal, a salt, and pruna, a live coal) is nitrate of potassium melted over a fire and cast into cakes or bullets. The nitric radical is univalent (NO3′)” (Attfield, 1835) It correlates with Sal Prunella, fused Potassium Nitrate (Saltpeter) from the Glossary of Drugs Prescribed or Dispensed in Colonial New England from 1620 to 1820.
Hooper, Robert (1773 – 1835) (1811) Quincy’s Lexicon medicum. A new medical dictionary : containing an explanation of the terms in anatomy, physiology … and the various branches of natural philosophy connected with medicine. Royal College of Physicians of Edinburgh
Sal Prunella – Nitrat of Potash is rat of potash cast into flat cakes or round balls.
If an acid basis be perfectly saturated with oxygen, the acid, thus produced, is said to be perfect ; but if the basis pre- dominate, the acid is considered as imperfect. Modern chemists distinguish the former in Latin by the syllables icum, in English ic, and the latter in Latin by oscm, and in English by ous : thus the perfect acid of nitre is called acidurn nitri- cum, or nitric acid ; the imperfect acid of nitre, acidum nitrosum, or nitrous acid. There are some cases where an acid is capable of combining with an excess of oxy- gen, in which case it is said to be oxygenated ; and sometimes sicper-oxygenated. If the acidifiable basis be combined with oxygen, yet without showing any of the properties of an acid, the produce is then called an oxyd or oxyde : thus iron expo- sed to the air or water attracts the oxygen, and an oxyd of iron, the rust, is formed. The various acids employed medicinally are, the acetic, benzoic, tartaric, carbonic, citric, muriatic, oxygenated muriatic, nitric, nitrous, sulphuric and phosphoric.
NITRAS. (From nitrum, nitre.) A nitrate ; a salt formed by the union of the nitric acid and a different bases, as the nitrate of potash, soda, silver, &e
PRUNELLA. (From pruna, a burn, because it heals burns.) Brunella. Con- Solida minor. Symphitum minus.
- The name of a genus of plants in the Linmaen system. Class, Didynamia. Or- der, Gifinnospermia .
- The pharmacopoeia! name of what is also called self-heal. Prunella vulgaris of Linnaeus, foliis omnibus ocato-oblongis, serratis, petiohitis, it is recommended as an adstringent in haemorrhages and fluxes, as in gargles against aphthae and inflammation of tiie fauces.
Prunella vulgaris. The systematic name of the self-heal. See Prunella.
Prunelloe. See Plum
D. Pereira Gardner, M.D (1855) A New Medical Dicttionary containing an explanation of the Terms in Anatomy, Human and Therapeutics, Materia “Medica”, Pharmacy, Comparative, Physiological, Practice of Medecine, Obsterics, Chemistry, Botany, Surgery, Natural Phylosophy, with the formulas of the principal Pharmacopeias, and Valuable Practical articles on the Treatment of Disease on the basis of Hooper and Grant. Adapted to the present state of science, and for the use of medical students and the profession.
D. PEREIRA GARDNER, M.D., is professor of chemistry and medical jurisprudence in the Philadelhia college of medicinal formerly professor of Chemistry, etc., in Hampden Sidney College. Corresponding member of the Lyceum of natural history of new York, etc., etc. New York: Harpier & Brothers, Publishers. 1855.
Nitras potassas fusus. Sal prunella;. Nitrum tabulatum. This salt, besides the nitric acid and potash, contains a little sulphuric acid. Nitras soda:. Alkali mineralc nitralum. Nitrum cubicum. Nitrate of soda. A neutral salt composed of soda and nitric acid. Its virtues are similar to those of nitrate of potash, for which it may be safely substituted. NITRATE. See Nitras.
Nitrate of potash. See Nitre.
Nitrate of silver. See Argenti nilras. NI’TRE. (Nirpov. Nitrum, i, n.) Saltpetre. Potassm nitras. Saltpetre. Nitre is procured abundantly from natural beds in India. It may also be made artificially by combining decaying animal and vegetable matter with moist earth and lime, and washing the mixture occasionally, by which nitrate of lime is obtained, which, being treated with wood ashes, is converted into nitrate of potash. When pure, it is found in anhydrous, colorless, six-sided prisms, with dihedral summits. It is soluble in seven parts of water at 60. It is fused below a red heat, and decomposed by farther heat. It has a cooling, saline taste; is refrigerant and diuretic ; dose, gr. v. to sss. It is a powerful antiseptic and detergent body, and an irritant poison in large doses. It is an ingredient in gunpowder and fireworks. Composition, KO,NO,->. NITRIC. (Nitricus; from nitrum.) Of, or belonging to, nitre. Nitric acid. Acidum nitricum. It is obtained by the action of sulphuric acid and heat on nitrate of potash or soda. When pure, it is a colorless fluid, of a pungent odor, extremely caustic, sp. gr. 1-5, and contains fifty-four parts of real acid and nine of water, being a definite compound, the anhydrous acid being unknown; formula, NOs-f-HO. The acid is used as a caustic to warts and indolent ulcers. Aquafortis of commerce is impure dilute nitric acid, and contains from 25 to 50 per cent, of acid. Dilute acid acidum nitricum dilutum(V. S.) consists of acid, f. 3j’.; water, f. 3ix. This is farther diluted in practice, and used in typhoid fevers, chronic affections of the liver, and as a tonic and febrifuge. Dose, gtt. x. to 3ss. in a glass of water. When long used it produces ptyalism. Nitric oxide. Deutoxide of nitrogen. Nitric oxide of mercury. See Hydrargyri nitrico-oxydum.
Nitrico-oxtdum htdrargyri. See Hydrar’ gyri niirieo-oxydum. NI’TROGEN. (Nitrogenium, ii, n.; from virpov, nitre, and yevvau, to generate.) Azoto. An elementary, colorless, inodorous gas, forming four fifths of the atmosphere, irrespirable, not supporting having in this state no activity. Sym., N.; eq., 14-06; sp. gr., 972. It forms five compounds with oxygen, of which NO, the protoxide, is the laughing gas, and NO5, nitric acid. Nitrogen, with hydrogen, NH 3 , forms ammonia. This substance abounds in animal products, and in the most nutritious parts of vegetables. Nitrogen, deutoxide of. A compound of N0 2 . It is a transparent gas, and appears sometimes to act as a compound radical. Nitrogen, protoxide of. See Nitrogen. Nitro-leucic acid. See Leucine.
NI’TRO-MURIA’TIC ACID. Acidum nitromuriaticum (U. S.). Aqua rcgia. Mix nitric acid, giv., and muriatic acid, gviij. They become yellow, and acquire the power of readily dissolving gold. This mixture evolves chlorine. It is used 111 a very dilute state to sponge the feet, &c, and as an internal remedy in chronic affections of the liver and obstinate constipation, but is very irritant, and not to be used where febrile symptoms exist. Dose, til v. to fix., in a wine-glass of water. Nitro-sa’ccharic acid is formed by the reaction of nitric acid on sugar of gelatine. It is colorless, crystallized in prisms, and soluble. Form., (C 8 H 7 N.206+2N0 5 )-4-4HO. Mulder. Nitro-salicylic acid. See Salicyle.
NI’TROUS. Nilrosus. Of, or belonging to, nitre, or its combinations. Nitrous acid. Acidum nitrosum. The red fumes produced by exposing binoxide of nitrogen to oxygen. It may be condensed by cold or pressure into a colorless fluid, and. consists of NOi. It is soluble in nitric acid, but decomposed by water.
Nitrous oxide. Protoxide of nitrogen. Laughing gas. Ni’trum. Nitre.
Nitrum flammans. Nitrate of ammonia.
Nitrum purificatum. Purified nitre.
Nitrum stibiatum. Nitrum antimoniatum. Anodynum mineralc. An old preparation, made by dissolving the antimonium diaphoreticum in water, and evaporating to dryness. Nitrum vitriolatum. Soda? sulphas. NO’BILIS. (Quasi noscibilis; from nosco, to know.) Noble. Some objects of natural history, so called by way of eminence: thus gold and silver are called noble metals, and nobilis is the specific name of several plants. NOC T AM BUL A’TION. (Noctambulatio, onis, f.; from nox, night, and ambulo, to walk.)
Nitrate of potash. See Nitre.
Nitrate of silver. See Argenti nilras. NI’TRE. (Nirpov. Nitrum, i, n.) Saltpetre. Potassm nitras. Saltpetre. Nitre is procured abundantly from natural beds in India. It may also be made artificially by combining decaying animal and vegetable matter with moist earth and lime, and washing the mixture occasionally, by which nitrate of lime is obtained, which, being treated with wood ashes, is converted into nitrate of potash. When pure, it is found in anhydrous, colorless, six-sided prisms, with dihedral summits. It is soluble in seven parts of water at 60. It is fused below a red heat, and decomposed by farther heat. It has a cooling, saline taste; is refrigerant and diuretic ; dose, gr. v. to sss. It is a powerful antiseptic and detergent body, and an irritant poison in large doses. It is au ingredient in gunpowder and fireworks. Composition, KO,NO,->. NITRIC. (Nitricus; from nitrum.) Of, or belonging to, nitre. Nitric acid. Acidum nitricum. It is obtained by the action of sulphuric acid and heat on nitrate of potash or soda. When pure, it is a colorless fluid, of a pungent odor, extremely caustic, sp. gr. 1-5, and contains fifty-four parts of real acid and nine of water, being a definite compound, the anhydrous acid being unknown; formula, NOs-f-HO. The acid is used as a caustic to warts and indolent ulcers. Aquafortis of commerce is impure dilute nitric acid, and contains from 25 to 50 per cent, of acid. Dilute acid acidum nitricum dilutum(V. S.) consists of acid, f. 3j’.; water, f. 3ix. This is farther diluted in practice, and used in typhoid fevers, chronic affections of the liver, and as a tonic and febrifuge. Dose, gtt. x. to 3ss. in a glass of water. When long used it produces ptyalism. Nitric oxide. Deutoxide of nitrogen. Nitric oxide of mercury. See Hydrargyri nitrico-oxydum.
Nitrico-oxtdum htdrargyri. See Hydrar’ gyri niirieo-oxydum. NI’TROGEN. (Nitrogenium, ii, n.; from virpov, nitre, and yevvau, to generate.) Azoto. An elementary, colorless, inodorous gas, forming four fifths of the atmosphere, irrespirable, not supporting having in this state no activity. Sym., N.; eq., 14-06; sp. gr., 972. It forms five compounds with oxygen, of which NO, the protoxide, is the laughing gas, and NO5, nitric acid. Nitrogen, with hydrogen, NH 3 , forms ammonia. This substance abounds in animal products, and in the most nutritious parts of vegetables. Nitrogen, deutoxide of. A compound of NO2. It is a transparent gas, and appears sometimes to act as a compound radical. Nitrogen, protoxide of. See Nitrogen. Nitro-leucic acid. See Leucine.
NI’TRO-MURIA’TIC ACID. Acidum nitromuriaticum (U. S.). Aqua rcgia. Mix nitric acid, giv., and muriatic acid, gviij. They become yellow, and acquire the power of readily dissolving gold. This mixture evolves chlorine. It is used 111 a very dilute state to sponge the feet, &c, and as an internal remedy in chronic affections of the liver and obstinate constipation, but is very irritant, and not to be used where febrile symptoms exist. Dose, til v. to fix., in a wine-glass of water. Nitro-sa’ccharic acid is formed by the reaction of nitric acid on sugar of gelatine. It is colorless, crystallized in prisms, and soluble. Form., (C 8 H 7 N.206+2N0 5 )-4-4HO. Mulder. Nitro-salicylic acid. See Salicyle. . NI’TROUS. Nilrosus. Of, or belonging to, nitre, or its combinations. Nitrous acid. Acidum nitrosum. The red fumes produced by exposing binoxide of nitrogen to oxygen. It may be condensed by cold or pressure into a colorless fluid, and. consists of NOi. It is soluble in nitric acid, but decomposed by water.
Nitrous oxide. Protoxide of nitrogen. Laughing gas. Ni’trum. Nitre.
Nitrum flammans. Nitrate of ammonia.
Nitrum purificatum. Purified nitre.
Nitrum stibiatum. Nitrum antimoniatum. Anodynum mineralc. An old preparation, made by dissolving the antimonium diaphoreticum in water, and evaporating to dryness. Nitrum vitriolatum. Soda? sulphas. NO’BILIS. (Quasi noscibilis; from nosco, to know.) Noble. Some objects of natural history, so called by way of eminence: thus gold and silver are called noble metals, and nobilis is the specific name of several plants. NOC T AM BUL A’TION. (Noctambulatio, onis, f.; from nox, night, and ambulo, to walk.) Sleep-walking. Oneirodynia activa. Noctisu’rgium. Sleep-walking. Nocturnal blindness. See Hemeralopia and Nyctalopia. NOCTURNAL EMISSION. An emission of semen during the night, from weakness of the generative function or libidinous dreams. It is to be treated by tonics in the former case, and by the antiphlogistic regimen in plethoric youth.
Saltpetre. Nitre.
Wootton, A. C.. (1910) Chronicles of pharmacy, Vol. I. Macmillan and Co., Limited, ST. Martin’s Street, London, Richard Clay and Sons, Limited, Bread Street Hill, E.C., and Bungary, Suffolk.
Sal Prunella
Sal Prunella was at one time in high esteem, as it was believed that by the process adopted for making it the nitre was specially purified. Purified nitre was melted in an iron pot and a little flowers of sulphur (1 oz. to 2 lb.) was sprinkled on it, a little at a time. The sulphur deflagrating was supposed to exercise the purifying influence on the nitre. The actual effect was to convert a small part of the nitrate of potash into sulphate. It was first called Sal Prunella in Germany from the belief that it was a specific against a certain plum-coloured quinsy of an epidemic character. Boerhaave advised the omission of the sulphur, but believed that melting the pure nitre and moulding it was of medicinal value by evaporating aqueous moisture.
Nitre and flowers of sulphur were deflagrated together before the Sal Prunella theory was invented, equal quantities being employed. The resulting combination, which was of course sulphate of potash, was known as Sal Polychrestum, the Salt of Many Virtues.
Nitre
Among the ancient Greeks and Romans generally meant carbonate of soda, sometimes carbonate of potash. The Arab chemists, however, clearly described nitrate of potash. In the works attributed to Geber and Marcus Græcus, especially, its characters are represented. Raymond Lully, in the thirteenth century, mentions sal nitri, and evidently alludes to saltpetre, and Roger Bacon always meant nitrate of potash when he wrote of nitre. It was not, however, until the seventeenth century that the term acquired the definite meaning which we attach to it.
At the beginning of that century there was much discussion as to the formation of nitre, as it had been held that the acid which combined with the alkali was ready formed in the atmosphere. Glauber was the first to argue that vegetables formed saltpetre from the soil. Stahl taught that the acid constituent of nitre was vitriolic acid combined with phlogiston emanating from putrefying vegetable matter.
After gunpowder had become a prime necessity of life, saltpetre bounded upwards in the estimation of kings and statesmen. In France in 1540 an Edict was issued commissioning officials called “salpêtriers” in all districts who were authorised to seek for saltpetre in cellars, stables, dovecotes, and other places where it was formed naturally. No one was permitted to pull down a building of any sort without first giving due notice to the salpêtriers. The “Salpêtrière” Asylum in Paris recalls one of the national factories of nitre. During the French Revolution citizens were “invited” to lixiviate the soil and ceilings of their cellars, stables, etc., and to supply the Republic with saltpetre for gunpowder. The Government paid 24 sous, 1s., a pound for the nitre thus procured, though, as this was no doubt paid in assignats, it was cheap enough. It was estimated that 16,000,000 lbs. a year were thus provided.
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