Extract of the Minutes of the Philosophical Society at Oxford, March 18. 1683/4 Concerning Irish Slat

una cum earumdem Virtutibus secundum novissima Botanicorum Fundamenta generali quadam Methodo commonstrans edita a D. Christiano Ludovico Wellschio Lipsi 1697. 12mo. 2. Juli Pflugk equitis Saxonici epistola ad per illustrem atq. Generosissimum Virum Ludovicum a Seckendorff virum de utraq; republica meritissimum, praeter fata bibliotheca Budensis, Librorum quoq; in ultima expugnatione repertorum catalogum exhibens Jen. 1688. in 8vo. 3. Dissertatione epistolare del fosforo minerale o sia della pietra illuminabile Bolognese, à sapienti ed eruditi signori Collelltori degli acta eruditorum di Lipsia, Scritta da Luigi Ferdinando Conte Marsigli, &c., Lips. 1698. in 4to. XV. A Catalogue of some Books lately Printed or now Printing beyond Sea. --- I. Extract of the Minutes of the Philosophical Society at Oxford, March 18. 1682. concerning Irish Slat. IT having been discours'd to us about Nine or Ten Months since, by the ingenious Mr. Kenwrick, Physician at Worcester, that the Irish Slat Pulveriz'd, and infus'd in Water for a Night, or less, would impart its Vitriolick Quality so far forth to it, that it would strike of a faint reddish Colour with Powder of Galls (as the Vitriolic Waters of Tunbridge, Astrop, and divers others do, and as you see it has in some Measure done in the Example here before you) it not only led me to believe that these Waters, some of them, might as well issue from Slat as an Iron Oar; unless it should appear, that this sort of Slat were an Iron Oar too, which put me upon calcining it for Three or Four Hours after the manner of Dr. Lister, to experiment, whether it would then (like the other Iron Oar) apply to the Magnet; wherein tho' I was altogether unsuccessful, the Magnet not taking the least notice of it, yet it afforded me another Discovery altogether as satisfactory, which is the Matter I have at present to communicate to you; viz. That upon Torrefaction it was all become a Yellow Ochre, and would score like it; tho' this here I have to shew you, be grown a little too dark by much burning, which further persuades me, that the Yellow, or rather Orange-coloured Sediment we find at the Bottom of these Fountains, comes rather from this sort of Slat, than an Iron Ore; for I much question whether some of the Yellow Ochres (tho' it's plain the Red ones do) come from, or are, Iron Ores; but I intend to calcine this further the next Week, whereof you shall have an Account the next Meeting, but doubt of my Success, because the Shotover Yellow Ochre will not own the Magnet after Thirty-six Hours Calcination, or better. II. Some