Part 5

§ 41.

Foſſil fixed ALKALY is only found in combination with acids, rarely with the vitriolic (§ 47) or nitrous (§ 48), principally with the muriatic (§ 49) or aerial (§ 55).

§ 42.

Volatile ALKALY is frequently found in clays, doubtleſs in a mild ſtate, for the help of art is required to render it cauſtic. It is alſo found united to the vitriolic (§ 50) and the muriatic acids (§ 52.)

§ 43.

ACIDS united to alkalies form NEUTRAL SALTS. Theſe diſſolved in water are no ways diſturbed by the addition of an alkaly, and generally by evaporation concrete into cryſtals. If by proper teſts they ſhew neither acid nor alkaline properties they are ſaid to be perfect neutrals, but imperfect when from defect in quantity or ſtrength of one ingredient the peculiar properties of the other more or leſs prevail.

We now proceed to conſider the native ſalts of both kinds.

NEUTRAL SALTS.

§ 44.

Alkali vegetabile vitriolatum (tartar of vitriol) ſeldom occurs ſpontaneouſly, unleſs where tracts of wood have been burnt down.

§ 45.

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, 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 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, London, and elſewhere. Sometimes it abounds in ſuch quantities that fleſh boiled in theſe waters turns red.

§ 46.

ALKALI vegetabile ſalitum (digeſtive ſalt) is ſometimes though rarely met with; generated perhaps by the deſtruction of animal and vegetable ſubſtances.

§ 47.

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.

§ 48.

ALKALI minerale nitratum (cubic nitre) rarely occurs but where maritime plants putrify.

§ 49.

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.)

§ 50.

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. 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.

§ 51.

ALKALI volatile nitratum (nitrous ammoniac) is generally found along with common nitre.

§ 52.

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.)