The works of the Honourable Robert Boyle, Esq., epitomiz'd by Richard Boulton ... ; illustrated with copper plates.

EXPERIMENT VI.

* 1.1 Having Distill'd Oyl of Vitriol with a Solution of Nitre in a Glass Body and Head plac'd in Sand, I drew from it a Spiritus Nitri, which be∣fore Rectification would dissolve Silver, tho' it was diluted with Water treble to the weight of the Nitrous Parts. And from the Matter left be∣hind, and evaporated to a Driness, I obtain'd a Salt, which would shoot into Crystals, neither like those of Crude nor fixt Nitre, nor those of Vitriol, but of a Figure hard to be describ'd. As for the other Qualities of it, it was easily fusible by Heat, yet was not inflammable like Nitre, tho' quick Coals were thrown upon it in a Crucible; for it was so far from that, that when it was hot enough to kindle Sulphur, it neither flash'd nor flam'd it self, as Salt-Petre usually does; yet this white Substance, being kept in Fusion for a while, with a little piece of Charcoal in it, smell'd very

strong of Sulphur, and had a very Fiery Taste on the Tongue, as also a Colour very red.

Encourag'd by these Circumstances, (they be∣ing agreeable to what Glauber relates of his Salt) and since he made use of Vessels of Silver, I judg'd it could not be Aqua fortis that he open'd the Sea-Salt with; nor common Spirit of Salt, because too weak; wherefore having put an equal weight of Oyl of Vitriol, and Sea-Salt together, into a Glass Cucurbite set in Sand, I obtain'd, besides Phlegm, a Spirit of Salt; which mix'd with Spirit of Nitre, dissolv'd Crude Gold; and likewise when pour'd upon Spirit of Urine, and fermented, till there no longer succeeded an Ebullition, after a gentle Evaporation, it shot into Crystals, like Combs and Feathers; from whence it appear'd to be of a like Nature to Sal Armoniack. The Experiment sometimes also succeeded, when in∣stead of Oyl of Vitriol, I made use of Oyl of Sulphur by the Bell.

But to apply this Experiment to our present Purpose; we may observe, That tho' Sea-Salt be so fixt, as not to be rais'd without a considerable quantity of beaten Bricks, to prevent its Fusion, and a naked Fire; yet when its Parts are un∣lock'd by an Addition of Oyl of Vitriol, they may be carry'd over with a Moderate Fire in Sand, the Vitriol being fix'd and left behind; yet in other respects considerably chang'd, so as to be void both of the Taste of Sea-Salt and Vitriol.

And from this Experiment, what I formerly in∣timated, likewise appears; viz. That the Figures of Salts, by being embody'd with other Substances, might be so far chang'd, as to shoot into Crystals

of very different Shapes: For from the Caput Mortuum Dissolv'd, Filtrated, and leisurely Coa∣gulated, may be obtain'd Crystals, much more transparent and of a different Figure from those of Sea-Salt, and from each other.

But to conclude this Experiment, I have found this Preparation of Sal Mirabilis very uncertain and tiresome, by reason of the Disparities of Bodies taken to be Oyl of Vitriol.

Notes

• * 1.1

  Several Phaenome∣na exhibi∣ted by a Mixture of Oyl of Vi∣triol, &c.