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 Praecipitated 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.

[25] The Curious Reader that desires further Information concerning Lakes, may Resort to the 7th Book of Neri’s Art of Glass, Englished (6 or 7 years since the Writing of this 49th Experiment) and Illustrated with Learned Observations, by the Inquisitive and experienc’d Dr. Charles Merret.

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.