NEUTRAL
SALTS.
Alkali vegetabile vitriolatum (tartar of vitriol) ſeldom occurs ſpontaneouſly, unleſs where tracts of wood have been burnt down.
Alkali vegetabile nitratum (common nitre) forms upon the ſurface of the earth where vegetables, eſpecially when mixed with animal ſubſtances, putrify. The alkaline baſis previously exiſts in the plants[19], but the origin of the acid is not ſo well underſtood: whether it lies concealed in the vegetable acid, and by means of the putrefactive proceſs ſufficiently dephlogiſticating it, is evolved; or whether the purer part of the atmoſpheric air contains nitrous acid fully ſaturated with phlogiſton, which[20] upon the alkaly being ſeparated by the putrefaction is attracted and extricated by it, and upon loſing its inflammable principle aſſumes its accuſtomed form. Nature perhaps operates in both ways; the latter however ſeems clearly confirmed by a very remarkable experiment (§ 60.)
As nitre is annually produced in large quantities, it cannot but ſometimes be found in ſprings or wells, as has been obſerved at Berlin[21], London[22], and elſewhere[23]. Sometimes it abounds in ſuch quantities that fleſh boiled in theſe waters turns red.
ALKALI vegetabile ſalitum (digeſtive ſalt) is ſometimes though rarely met with; generated perhaps by the deſtruction of animal and vegetable ſubſtances.
ALKALI minerale vitriolatum (Glauber’s ſalt) is ſometimes found in waters. Some of the lakes in Siberia and Astracan contain it, and many ſprings in other places.
ALKALI minerale nitratum (cubic nitre) rarely occurs but where maritime plants putrify.
ALKALI minerale ſalitum (common ſalt) plentiful every where as well in the earth, where it forms ſtrata more or leſs thick (ſal gem), as alſo diſſolved in ſprings and lakes, and in the ſea. (ſea ſalt.)
ALKALI volatile vitriolatum (vitriolic ammoniac) is ſcarcely found any where but in places where the phlogiſticated fumes of vitriolic acid ariſe from burning ſulphur, and in putrid places are abſorbed by the volatile alkaly.[24] Thus at Fahlune the acid vapour from the roaſted minerals produces this ſalt in the neceſſary houſes. It is ſometimes alſo formed in the craters of volcanoes.
ALKALI volatile nitratum (nitrous ammoniac) is generally found along with common nitre.
ALKALI volatile ſalitum (ſal ammoniac or common ammoniac.) I have examined ſome from Veſuvius, and ſome from the Solfaterra near Naples.
The ſalts hitherto enumerated are perfect neutrals, thoſe which follow are imperfect (§§ 53, 56.)
ALKALI FOSSIL, only in part ſaturated with a peculiar acid is called tinkal; after depuration, borax. It is dug out of the earth in the kingdom of Thibet[25]. Borax takes nearly an equal weight of acid before the alkaline properties entirely diſappear[26].
I believe no one has yet found the acid of borax united either to the vegetable or volatile alkalies.
ALKALI VEGETABILE aeratum (mild vegetable alkaly) is hardly ever found native, unleſs in the neighbourhood of woods deſtroyed by fire.
In the year 1774, at Douai in Flanders, a ſpring was diſcovered ſurrounded by a wall, whoſe waters, beſides other impregnations, contained 11 grains of vegetable alkaly in a pint[27].
ALKALI MINERALE aeratum (mild foſſil alkaly, natron, the nitre of the ancients) is found plentifully in many places, particularly in Africa and Aſia, either concreted into chryſtallized ſtrata, or fallen to a powder; or effloreſcing on old brick walls, or laſtly, diſſolved in ſprings. It frequently originates from decompoſed common ſalt. I am not ignorant that the acid of common ſalt adheres ſtrongly to its baſis ſo as not to be expelled by fire; but perhaps the viciſſitudes of the atmoſphere continually acting for ages, may be more powerful. In immenſe plains covered over with this alkaly, ſcarcely any common ſalt is found upon the ſurface, but the deeper you dig the more it is contaminated by it, the common ſalt being yet undecompoſed for want of acceſs of air.
ALKALI VOLATILE aeratum (mild volatile alkaly) has been found in pump waters in London[28], in Lauchſtadt[29], at Frankfort on the Mayne[30], and copper immerſed therein is ſaid to have been diſſolved into a blue liquor.
The three alkalies mentioned above as ſaturated with aerial acid, differ greatly from cauſtic alkalies, in the mildneſs of their taſte, in their property of chryſtallizing, and in their efferveſcing with acids which expel the aerial acid, but they ſtill change vegetable blues to greens, though not ſo powerfully as the cauſtic alkalies do. Therefore, although the ſubtil aerial acid in other reſpects gives them neutral properties, yet in this it does it but imperfectly.
The compounds of earths and acids which poſſeſs ſolubility mentioned at § 20, are decompoſed and precipitated by mild, but not by phlogiſticated alkalies.
TERRA PONDEROSA vitriolata, (heavy ſpar, marmor metallicum, calk) is placed with the earths (§ 89.) Terra ponderoſa nitrata i. e. terra ponderoſa united to the nitrous acid, perhaps exiſts ſomewhere, but has never been met with; neither has the terra ponderoſa united to the aerial acid, yet been found[31]. Terra ponderoſa ſalita i. e. terra ponderoſa with the muriatic acid Mr. Hielm ſays[32] is diſſolved in the waters of the lake Vettern and its neighbourhood.
CALX vitriolata (gypſum, ſelenite) is not only found diſſolved in various waters, but alſo in many places forms immenſe ſtrata. It is placed by all mineralogiſts amongſt the earths, but I think improperly. When burnt it generates heat with water, but in a leſs degree than lime does.
CALX nitrata (nitre of lime; terrene nitre) is ſometimes found in water, but very ſparingly. It is ſaid that the chalk hills in ſome parts of France become ſpontaneouſly impregnated with nitrous acid, which may be waſhed out, and after a certain time they will become impregnated with it again.
CALX Salita (fixed ammoniac) occurs very frequently in waters.
CALX aerata (marble, limeſtone, chalk, ſpar) is very commonly found diſſolved in waters in conſequence of an exceſs of the aerial acid. When it greatly abounds, the water is ſaid to be hard (cruda). By boiling, or by evaporation, it depoſits ſtreaks or cruſts of calcareous matter.
Calx aerata is not ſoluble in water without an exceſs of the ſubtil acid, and therefore might properly be referred to the earths (§ 21).
MAGNESIA vitriolata (Epſom ſalt) is not unfrequent in the waters of England, Bohemia, and other countries. This ſalt is preſently decompoſed by lime water, which circumſtance readily diſtinguiſhes it from the alk. min. vitriol. or Glauber’s ſalt.
MAGNESIA nitrata (magneſia and nitrous acid) is uſually found together with nitre.
MAGNESIA ſalita (magneſia and muriatic acid) is found diſſolved in various waters, but plentifully in ſea water, to which it gives a diſagreeable bitterneſs.
MAGNESIA aerata (common magneſia) with an exceſs of aerial acid it becomes ſoluble in cold water, otherwiſe it is ſcarce ſoluble at all, and therefore ſhould be claſſed with the earths. (§ 21.)
ARGILLA vitriolata (alum) is ſometimes ſpontaneouſly generated by the decompoſition of pyrites lodged in clay, or in argillaceous ſchiſtus.
It is found in a ſpring at Steckenitz in Bohemia[33], in Eaſt Bothnia and elſewhere. What is commonly called plumoſe alum is not a ſaline ſubſtance.
ARGILLA (clay) united to the nitrous, muriatic[34], or aerial acids has not to my knowledge hitherto been found in any waters.