draw off again to a thin skin, and let it Cristallize, and this seven times repeat, put the Stones in a Stove of the same heat as the Sun in Dog-days, and in such a heat they will turn into a White Powder. The Vitriol being thus prepared, put it in a Cucurbit, with a long neck, well Sealed, in Ashes, under which put a Lamp, so as that the heat exceed not the Sun in March, thus leave it, till the Vitriol begins, to be yellow, being yellow, the Fire of the Lamp increase one Degree, and thus leave it ten days and nights, or till it be∣gins to be red, then again increase the Fire in the Lamp ano∣ther Degree, and thus continue, till the Matter be alto∣gether red as a Ruby, then increase the Fire yet ten days, and the hidden part of the Vitriol is now manifest, and prepared in its redness, as a volatile Matter: The redness thus re∣maining, take the Glass out of the Ashes, and the Matter out of the Glass, and put it in a stronger Glass, to which pour the best Vinegar well rectify'd, stop it well, set it in Bal∣neo, so let it stand four days, yet stirring the Matter with a Spatula made of Haslewood, three or four times a day, let it cool, decant the Vinegar into another Glass, pour new upon the Matter, digest in Balneo, as before, this repeat with new Vinegar three times, the decanted Vinegar gent∣ly draw off, till the Matter remains in the form of a Salt at the bottom, to which, pour new sharp Vinegar, put it four days in Balneo, as before, to dissolve, and let that be re∣peated, till it be free from any sediment: Then coagu∣late the Matter into a dry Powder, and put it in a Glass Cucurbit, with a wide mouth, and a large Alembick, day the Receiver in a Vessel full of Water, lute the Joynts firm, and distil with an open Fire, but very gently, the space of four hours, after that strongly, and the Spirits will ascend yellow, which are called Air; continue the Fire in the same degree, till the Alembick begins to be red; then slow the Fire, that the Alembick may be of a blood colour, then increase the Fire still, that the Glass may be burning hot as a red hot Iron, which keep in that heat, till the Alembick be made of a Snow Colour, then strengthen the Fire yet more, that the Alembick may again be clear and transparent, then let it cool, remove the Receiver, and pour the Oyl into a pure