3?2 A L K 
tial earth into which it turns becomes efflorefccnt; then 
the earth is elixiviated feveral times, and the water, hav¬ 
ing thus imbibed the alkali, is boiled, evaporated, and 
poured into proper pans, wherein the alkali goes out and 
chryftallizes, and becomes equal to the bed barilla.” 
The alkalies may be rendered cauftic by the addition of 
'quick-lime. In this (late they deftroy the parts of a liv¬ 
ing animal in a manner fimilar to fire ; whence they are 
called potential cauteries, as the former is called th cattual 
cautery. The kali purum, formerly lapis ivfernalis, of the 
fhops, is of this kind. The alkalies attract moifture from 
the air when in their cauftic ftate, though neither the folTil 
alkali nor its combinations do fo in any other cafe. It is 
only in their cauftic ftate alfo that they unite with oils* or 
diftblve in fpirit of wine ; which laft they have been fup- 
pofed to purify. 
Volatile alkali, when procured immediately by the dif- 
tillation of any fubftance capable of yielding it, is obtain¬ 
ed in a ftate fimilar to that in which the alkalies are ufually 
met with, viz. half mild and half cauftic. By expoftng 
the liquid alkali to a great quantity of fixed air, we may at 
laft have it perfectly mild and neutralifed; in which ftate 
it appears as a white fait extremely volatile, though lefs 
fo than the pure cauftic alkali. It dilfolves very readily in 
water; but unlefs Come cauftic fpirit, or fome lime or fixed 
alkali, be added, in order to abftradt part of the fixed air, 
it will fcarcely exhibit the charaf'teriftic of volatile alkali, 
viz. a pungent and urinous fmell. The addition of fixed 
■air, however, makes very little difference with regard to 
the chemical combinations of this fait; for, as fixed air has 
a very (lender power of -acidity, it is expelled by every 
other acid with the greateft eafe, and the fame combinations 
formed as though it had not been prefent. The only dif¬ 
ference is, that, when a mild alkali is added to an acid, a 
ftrong effervefcence is produced by theefcape of the fixed 
air, while, with the cauftic alkali, the mixture is made 
without any ebullition. 
Befides their attraflion for acids, the alkalies have alfo 
an attraction for oils, fulphur, and fpirit of wine, in the 
inoift way, when the falts are deprived of their fixed air; 
and in this, as well as the dry way, with feveral metals, 
and vitrifiable earths and (tones, as has been already men¬ 
tioned. With oil the vegetable fixed alkali forms a foap, 
though lefs perfeCt than that made with the cauftic mineral 
alkali. When combined with fixed air, they fcarcely unite 
with oils. Boiled with fulphur, or melted with it in their 
dry ftate, they unite into a very fetid compound called 
heparJulpliuris, which is foluble in water, but totally and 
very quickly decompofed by the contaCt of air. Vegeta¬ 
ble alkali unites with iron, tin, and zinc; corrodes copper, 
and runs with it into a liquor of a deep blue colour, and 
joins with lead in fufion. It does not aft upon gold in its 
metallic ftate; but, if a fufficient quantity be added to a 
folution of gold in aqua regia, the calx of the metal will 
be firft precipitated and afterwards diftolved. 
Vegetable alkali is a principal ingredient in the powders 
called Jluxcs, ufed for the fufion of metalline ores. It pro¬ 
motes the fufion of earths, and forms glafs with the cryf- 
talline kind. It is foluble in an equal weight of diftilled 
water ; and, when expofed to the air, it foon attracts moif¬ 
ture from it, and flows into a liquid. In its cauftic ftate it 
dilfolves in fpirit of wine, and forms with it a red tinCture 
called Fan Helmont’s linElure of fait of tartar, formerly ufed 
both as an internal and external remedy, but now fallen 
into difrepute. 
Foflil alkali in its cauftic ftate unites with oil into an 
harder foap than that made with vegetable alkali. With 
fulphur it forms an hepar fulphuris in the fame manner as 
the vegetable alkali, and yields a tinClure with fpirit of 
wine, which difiolves part of the fait whilft hot, but lets 
it (all again in a cryftalline form when cold. Gold, filver, 
or quicklilver, are not affeCted by a folution of this fait; 
hut copper and tin are ditfolved by it in the open air. It 
stfefts tin, l¥ad, regulusof antimony, and cobalt, (lightly-; 
bat afts powerfully upon zinc, and forms a kermes mine- 
A L K 
ral with crude antimony. Copper, iron, bifmuth, zinc, 
antimony, and regulus of cobalt, fufed with two parts of 
foflil alkali, are almoft entirely diftolved in a very ftrong 
heat; but tin, lead, and regulus of antimony, treated in 
the fame manner only fuffer a partial folution. 
All the alkalies are of conliderable life in medicine, 
though there nnift be a confiderable diverfity in their ope¬ 
rations on the human body, as the vegetable alkali (hews 
itfelf fo much more acrid and powerful than the foflil. 
They unite immediately with acids, and change them into 
mild neutral falts; hence, if any of the ftrong mineral 
acids fall upon any part of the human body, and begin to 
corrode and give pain, the immediate application of the 
lixivium tartari, or of a folution of any of thofe alkaline 
falts in water, or of the falts themfelves in powder, will 
deftroy their caufticity, and prevent their doing further 
mifchie(: Or if any of thefe acids (hould drop on clothes, 
linen, or other fubftances, and alkaline falts are immedi¬ 
ately applied, they will neutralize the acid, and prevent 
its further corrofion : Or if a perfon fliould, through mif- 
take, fvvallow any of the mineral acids, or corrofive fub- 
limate, or any other corroding fait, which an alkali will 
decompofe, the taking into the ftomach folutions of the 
alkaline falts, or the falts themfelves in proper dofes, are 
the moll likely means of affording immediate relief., 
Fixed alkaline fait loofens the belly, and renders the 
eftedl of purgatives more lading, and is peculiarly ufeful 
againft that conftipation of the bowels w hich is generally 
attendant on the ftudious and fedentary. It deftroys aci¬ 
dity in the primae viae, converting them into a mild ape¬ 
rient fait, and thus removes a caufe of many chronical 
difeafes. It refoLves vifeid and glutinous humours, by 
which, and its gentle ftimulus, obftruftions are removed, 
and wherever it pafles fecretions are promoted. It loofens 
the texture of calcareous concretions, by ftrongly attract¬ 
ing their air; and, made into a ley with a final! quantity of 
lime, this power is increafed. In thofe flatulent diforders 
which arife from a deftruCtive bile it alfo affords great 
relief. 
As a principal medical efFeCt of alkaline fait is to atte¬ 
nuate the blood and humours, it is obvioufly improper in 
the feurvy, and all thofe diforders in which the texture 
of the blood is already too much enfeebled; in particular 
diforders this medicine is hurtful, by increafing that col- 
liquation which is always obferved to attend them. It is 
probable, that the reftridftions on the Jews with refpeCt to 
their diet, was in part from the fpeedy putrefcence to 
which the prohibited fubjeCts tend ; animal food is all 
alkalefcent, but fome more fo than others; all fifh foon 
putrify, but thofe without feales, and the (liell-fifti, the 
fooneft. 
Both the vegetable and foflil alkali applied externally 
in a cauftic ftate, firft irritate and inflame the (kin, and 
afterwards aft as fire in mortifying and deftroying it; and 
therefore have been much ufed by furgeons for opening 
buboes and other abfeefles, and for eating away proud or 
fungous flefti. Various formulae of cauftic alkalies are 
employed in medicine for different purpofes, for which 
fee Chemistry and Pharmacy. 
Alkali, or Sal Kali, y. in botany. See Salicor.- 
nia. 
AL'KALINE, adj. That which has the qualities of al¬ 
kali.—Any watery liquor will keep an animal from ftarv- 
ing very long, by diluting the fluids, and confequently 
keeping them from an alkaline ftate. People have lived 
twenty-four days upon nothing but water. Arbuthnot. 
To ALKA'LIZATE, v. a. To make bodies alkaline, 
by changing their nature, or by mixing alkalies with them. 
Alkalizate, adj. That which has the qualities of al¬ 
kali; that which Is Impregnated with alkali.—The colour 
of violets in their fyrup, by acid liquors, turns red, and, 
by urinous and alkalizate, turns green. Newton. 
ALK ALIZA'TION, f, The a# of alkalizating, or 
impregnating bodies with alkali. 
ALK^N'DA, /, in botany. See Myrtus. 
- ' : AL'KANET 
