ſometimes afford both) ſeems manifeſtly to contain a peculiar kind of Acid Spirit, generated in the Bowels of the Earth, and ſome kind of ſtony matter diſſolv'd by it. And though in making our ordinary Allom, the Workmen uſe the Aſhes of a Sea Weed (vulgarly call'd Kelp) and Urine: yet thoſe that ſhould know, inform us, that, here in England, there is beſides the factitious Allom, Allom made by Nature Without the help of thoſe Additaments. Now (Pyrophilus) when I conſider'd this compoſition of Allom, and that Alcalizate Salts are wont to Præcipitate what acid Salts have diſſolv'd, I could not but be prone to ſuſpect that the Curdled Matter, which is call'd the Magiſtery of Vegetables, may have in it no inconſiderable proportion of a ſtony ſubſtance Præcipitated out of the Allom by the Lixivium, wherein the Vegetable had been decocted, and to ſhew you, that there is no neceſſity, that all the curdl'd ſubſtance muſt belong to the Vegetable, I ſhall add, that I took a ſtrong Solution of Allom, and having Filtred it, by pouring in a convenient Quantity of a ſtrong Solution of Potaſhes, I preſently, as I expected, turn'd the mixture into a kind of white Curds, which being put to Filtre, the Paper retain'd a ſtony
Calx, copious enough, very White, and which ſeem'd to be of a Mineral Nature, both by ſome other ſignes, and this, that little Bits of it being put upon a live Coal, which was Gently Blown whilſt they were on it, they did neither melt nor fly away, and you may keep a Quantity of this White ſubſtance for a good while, (nay for ought I can gueſs for a very long one) in a red hot Crucible without loſing or ſpoiling it; nor did hot Water wherein I purpoſely kept another parcel of ſuch Calx, ſeem to do any more than waſh away the looſer adhering Salts from the ſtony ſubſtance, which therefore ſeem'd unlikely to be ſeparable by ablutions (though reiterated) from the Præcipitated parts of the Vegetable, whoſe Lake is intended. And to ſhew you, that there is likewiſe in Allom a Body, with which the fix'd Salt of the Alcalizate Solution will concoagulate into a Saline Subſtance differing from either of them, I ſhall add, that I have taken pleaſure to recover out of the ſlowly exhal'd Liquor, that paſs'd through the filtre, and left the foremention'd Calx behind, a Body that at leaſt ſeem'd a Salt very pretty to look on, as being very White, and conſiſting of an innumerable company of exceeding ſlender, and ſhining Particles, which
would in part eaſily melt at the flame of a Candle, and in part flye away with ſome little noiſe. But of this ſubſtance, and its odd Qualities more perhaps elſewhere; for now I ſhall only take notice to you, that I have likewiſe with Urinous Salts, ſuch as the Spirit of Sal Armoniack, as well as with the Spirit of Urine it ſelf, Nay, (if I much miſtake not) ev'n with Stale Urine undiſtil'd, eaſily Precipitated ſuch a White Calx as I was formerly ſpeaking of, out of a Limpid Solution of Allom, ſo that there is need of Circumſpection in judging of the Natures of Liquors by Precipitations wherein Allom intervenes, elſe we may ſometimes miſtakingly imagine that to be Precipitated out of a Liquor by Allom, which is rather Precipitated out of Allom by the Liquor: And this puts me in mind to tell you, that 'tis not unpleaſant to behold how quickly the Solution of Allom (or injected lumps of Allom) do's occaſion the ſevering of the colour'd parts of the Decoction from the Liquor that ſeem'd to have ſo perfectly imbib'd them.
Annot. II.
The above mention'd way of making Lakes we have tryed not only with Turmerick, but alſo with Madder, which yielded us a Red Lake; and with Rue, which afforded us an extract, of (almoſt if not altogether) the ſame Colour with that of the leaves.
But in regard that 'tis Principally the Alcalizate Salt of the Pot-aſhes, which enables the water to Extract ſo powerfully the Tincture of the Decocted Vegetables, I fear that our Author may be miſtaken by ſuppoſing that the Decoction will alwayes be of the very ſame Colour with the Vegetable it is made off. For Lixiviate Salts, to which Pot-aſhes eminently belong, though by peircing and opening the Bodies of Vegetables, they prepare and diſpoſe them to part readily with their Tincture, yet ſome Tinctures they do not only draw out, but likewiſe alter them, as may be eaſily made appear by many of the Experiments already ſet down in this Treatiſe, and though Allom being of an Acid Nature, its Solutions may in ſome Caſes deſtroy the Adventitious Colours produc'd by the Alcaly, and reſtore the former: yet
beſides that Allom is not, as I have lately ſhown, a meer Acid Salt, but a mixt Body, and beſides, that its operations are languid in compariſon of the activity of Salts freed by Diſtillation, or by Incineration and Diſſolution, from the moſt of their Earthy parts, we have ſeen already Examples, that in divers Caſes an Acid Salt will not reſtore a Vegetable ſubſtance to the Colour of which an Alcalizate one had depriv'd it, but makes it aſſume a third very differing from both, as we formerly told you, that if Syrrup of Violets were by an Alcaly turn'd Green, (which Colour, as I have try'd, may be the ſame way produc'd in the Violet-leaves themſelves without any Relation to a Syrrup) an Acid Salt would not make it Blew again, but Red. And though I have by this way of making Lakes, made Magiſteries (for ſuch they ſeem to be) of Brazil, and as I remember of Cochinele it ſelf, and of other things, Red, Yellow or Green which Lakes were enobled with a Rich Colour, and others had no bad one; yet in ſome the colour of the Lake ſeem'd rather inferiour than otherwiſe to that of the Plant, and in others it ſeem'd both very differing, and much worſe; but Writing this in a time and place where I cannot provide my ſelf of Flowres and other Vegetables to proſecute
ſuch Tryals in a competent variety of Subjects, I am content not to be poſitive in delivering a judgment of this way of Lakes, till Experience, or You, Pyrophilus, ſhall have afforded me a fuller and more particular Information.
Annotation III.