CHAP. I.
In which is shewed the way of making both an ESSENTIAL and a MARINE Salt, out of the LIXIVIAL Salt of a Plant.
OMETIME since, I took the boldness to present my thoughts to this Honourable and Learned Body in a Discourse concerning Mixture. Wherein I have endeavoured to lay such a Foundation, as might hereafter reduce the Doctrine hereof to Experience and Practice; and to demonstrate, the Power and Use of Artificial Mixture. And in further proof of what is therein asserted, I have since made a continuation of Experiments upon the same Subject, in Two Methods. One in the Mixture of several Menstruums, both Acid and Alkaline, with all Sorts of Bodies. The Other, by calcining them, or, as it were, mixing them with the Fire.
2. §. I shall now proceed to a Third, which is, the mixing them with the Aer or exposing them to it; another of Natures grand Menstruums; which goes sometimes further than the Fire it self, in the dissolution of Bodies. This I have formerly mentioned for the Imitation of Nature, in producing a Marine or Muriatick Salt out of the Lixivial Salt of a Plant. Discourse of Mixture Ch. 5. Inst. 2. But some Learned Persons then present, seeming to doubt of the Experiment; I thought it requisite to prosecute the same a little further; that so, if possible, it might become clear and unquestionable. And because that Method was imperfect, and required half a year, or a longer time: I bethought my self of an other way; which proved far better, and more expedite. And which, withall, afforded me, not only a true Marine Salt, out of the Lixivial Salt of a Plant; but also another kind of Salt, different from them both: which may not be improperly called, an Essential Salt or Nitre of Plants. The History or manner of the production of them both, is as follows.
3. §. December 15. 1675, I took about half a pound of a strong Solution of the Lixivial Salt of Firne: and pouring it into an Earthen Pan, well glazed, broad and shallow, exposed it therein to the open Aer, in a Chamber Window, to evaporate of it self. Tab. 83.
4. §. This Solution or Lee, although it was very clear before, and having stood corked up in a bottle many days, had no sedement: yet standing now in the open Aer, within the space of 4 or 5 days, it began to let fall a very white Sedement, like fine Chalk; which encreased daily for 8 or 10 days; amounting at last to about half a Drachm of white, light and meer Earth, altogether insipid, and when it was well washed, stirring not upon the Affusion of Acids.
5. §. Within the space of a day or two after this white Sedement began to fall to the bottom; there was also gathered on the top, a kind of soft Scum or Cremor, wherewith the Solution was covered all over.
6. §. Within 8 or 9 days after the first exposing of the Liquor, or 2 or 3 days after the gathering of the Cremor; that Salt, which I take leave to call, an Essential Salt of Plants, began to appear; shooting into several little Crystals. These Crystals, as they grew bigger, began to sink, and at last fell down to the bottom of the Pan.
7. §. Upon their first generation or shooting, the said Cremor presently breaks, leaving a bare space round about each Crystal; and upon the bounds of every space is indented; Tab. 83. the space growing bigger and bigger together with the Crystal in the Centre. And so, by that time the Crystals are grown to a considerable number and bigness, the Cremor vanishes away, the several Circles or bare places breaking at last one into another all over the Surface of the Lee. After which, it never comes again.
8. §. From whence it seemeth, That the several Circles or bare Spaces about the Crystals, are made for the more free admission of the Aer, requisite to their Generation. For as there is no Crystal begins to be formed before there is a breach made in the Cremor: so that breach is enlarged together with the Crystal. So that as the falling of the Sedement and the gathering of the Cremor, sheweth that the Aer, as a Menstruum separates some part from the Lee: so the breaking of the Cremor afterwards, that as a Vehicle, it brings something to it: both in order to the Generation of the Crystals. Nature taking a Method for the Generation of simpler Bodies, as well as of those which are Compounded and Organical.
9. §. The Figure of these Crystals is angular and oblong, most of them about the fifth, sixth or seventh of an Inch; but none of them very regular. Yet we are not hence to conclude, but that with the help of some Circumstances which might be wanting in the shooting of these; some portion of regular ones may be obteined from this, as well as other Lixivial Salts hereafter mentioned.
10. §. They are somewhat transparent, and of a dark Ambar Color, or like that of brown Sugar-Candy. Of a quite different Taste from that of the Solution or Lee out of which they are bred; being not at all Lixivial, but very weak and mild; not Salt, but Bitter in a good degree.
11. §. It is also observable, that Alkaline and Acid Salts being both poured severally upon these Crystals, they stir not, nor are any way affected with either of them. So that these Crystals are no sort of Tartar, or Tartareous Salt. As is plain, from the manner of their Generation; Tartar being still bred in close Vessels; these never, but by exposing the Liquor to the Aer. As also from their Taste, being not sower, in the least, but bitter. And in that Tartar will make a Bullition with Alkaline Salts, which these will not do. Upon which accounts it appears, that they are a Salt different in Nature from all other Salts hitherto known, or a new Species added to the Inventory of Nature.
12. §. These Crystals within the space of about a fortnight after their first Generation, did also cease to shoot any more, but only increased a little in their Bulk. After which time, I dayly expected to see the production also of a true Marine Salt. And about two months after the said Essential Crystals had done shooting, and not before, this also began to shoot, in many small Crystals, and at the top of the Solution, as the other did, still falling to the bottom as they grew biger.
13. §. The Size of most of them was near that of the Flakes or Grains of Bay-Salt. The Colour of some of them white, of others transparent; and of others white in the Centre, with transparent Edges; as is also usual in the Crystals of Common Salt.
14. §. The Figure of most is a perfect Square, and of very many coming near to a Cube; which is also the Figure of Common Salt, and seldome an exact Cube. An exact Cube, being the constant property of no Marine Salt, that I know of, except that of the Dead Sea. Tab. 83. Divers of them were also raised as it were by several steps from a deep Centre to the Top: as is often seen in the common shooting of Common Salt; and not in any other. Their Taste is neither Lixivial, as that of the Solution out of which they shoot; nor bitterish, as that of the Essential Crystals; nor sowerish, as that of Tartar; but the perfect Taste of Common Salt.
15. §. It is also to be noted, That if Oyl of Vitriol, and some other strong Acids, be poured upon this artificial Sea-Salt, they make an Effervescence together: but if Spirit of Salt or Spirit of Nitre either be poured on it, though it be never so strong it stirreth it not. In both which, and all the formentioned respects, it answers to the Properties of a Marine or Common Salt, which no other Salt doth. I conclude it therefore to be a true Marine Salt produced by Art in the imitation of Nature.