CHAP. II.
Of the QUANTITIES afforded by the Parts of several Plants distinctly calcin’d.
SHALL next set down some Tryals, upon one Part of a Plant, as well Organick, as Content, separated from the rest; in answer to these supposed Queries.
Quer. 1. What Proportion doth the Lixivial Salt of the Pith or Pithy Part of a Plant, bear to that of the Fibrous, or of the Woody Part? Or whether is there a Fixed Salt always found in either of them? A sufficient Answer to which, must be built upon many Tryals. At present I shall mention only Two; one upon Starch, answerable to the Pithy Parts; the other upon Flax, consisting almost wholly of the Nervous or Towy Fibers: of the Volatile parts §. 50, 51, 52. whereof, chiefly, I have given some account in the foregoing Idea.
Of Starch, ℔j yieldeth about ℔¼ not of Ashes, but of Black Coal. For though it be exposed in a Calcining Furnace to a vehement fire, for 5 or 6 hours, which is longer then will serve to calcine most Bodies: yet would it not in the least part, be reduced to Ashes; but to the last continued (though the fierceness of the Fire consumed part of it) as black, as when it was first burnt. So strangely was the remaining part of the Sulphur fixed to the Earth; that in flying away, it did volatilize and carry that away with it. In this Coal or Cinder, there is not the least of a Lixivial or other Taste. And although, upon Tryal I find, That the Pith of many Plants, as of a Cabbage Stalk, will yield some quantity of Lixivial Salt; yet it is probably, that generally, it yields less than the Wood.
Of Flax, ℔j yields not above 50 Grains of Caput Mortuum or white Ashes, which are Salt. According to vulgar conceit, it would seem to be a very dry Body: yet of 153 parts, 152 are volatile, and being distilled would have been collected into Liquor. Hence also appears the great and unexpected Variety in the Proportion of the Earthy Parts, as well as the other Principles of Bodies. Or else, that there are divers kinds of Earths, even in Plants, of which, as well as of Salts &c. some are volatile. For of ℔j of this Plant, there remaineth fixed but 50 Grains: whereas of ℔j of Rhubarb, there will remain near 1920 Grains, i. e. 88 times as much as the former.
Quer. 2. In what proportion is the Lixivial Salt found in the Gumms of Plants? and whether is it yielded, more or less, by all? For answer to which, I caused the Eleven following, of each two Ounces, to be calcin’d, and so observed,
That Common Rosin, yields but one Grain and ½ of Caput Mortuum. So that ℔j will yield but 12 Grains. In this Caput Mort. there is not the least particle of Salt, it being altogether insipid.
Mastick yields gr. 12 of Cap. Mort. But not the least part of Salt. Of this Rosin, it is observable; That being set, in a Crucible, within the fire, before it comes to have thick fumes, it boyls up with a very great foame or froath; and is the only Gum or Rosin (of the Eleven) that hath this property. So that I suspect, there is a great quantity of some kind of volatile Spirit, which then flies away; and so, in breaking through the Oyly parts, huffs them up to so great a froath.
Olibanum yields half a Drachm of Caput Mortuum. But it is to be noted, That the weight is encreased by certain little Spar-Stones, which in the burning of several parcels, I always found mixed with this Gumm. These being picked clean out, the Cap. Mort. weigheth not much more than that of Mastick. And is in like manner insipid, when the said Stones are picked out.
From hence it appears, how proper these Gums are for the Concoction of Salt Rheums; Discourse of Mixture Cap. Ult. according to what I have formerly suggested from another Experiment.
It may also be noted, that Rosin and Mastick, seem to be more purely Acidoleous Gums; not only from their consistence which is uniform; and their Smell, which is less strong and more pleasant: but also from the Acid Liquor they yield by Distillation; and in that the young Leavs of Fir, and especially of Pine, are sower; and ’tis probable that those of Mastick are so likewise. Whereby these, and other like Gums are more especially fitted for the abovesaid purpose. But Olibanum seems, besides its Acidity, to contein some Volatile Alkaly, and so to be an Acid-Alkaline Gum. For as it hath a stronger Smell than the former, so a hotter Taste; both the ordinary effects of an Alkaline Sulphur. And being infused in several Menstruums, appears to consist of two Bodies, one of them more Resinous than the other. Of which, it is probable, that the one is made by the Acid parts as the other by the Alkaline. Whereby it is very well adapted in some Cases, as in a Pleuresie, for removing the Coagulations of the Blood, or its disposition thereunto.
Asa fœtida yields no less than half its weight or an Ounce of Caput Mort. that is 8 times as much as that of the other Gumms, and 48 times as much as that of some of them. Yet doth it not contein one grain of Salt, so far as can be judged by its Tast. Yet the Strength and Loathsomness of the Smell and Tast of the Gumm do argue it to be highly impregnated with some kind of Volatile Alkaly proper to arrest those offensive Vapours (to use the vulgar word) which flying, either by the Blood or Nerves, from part to part, do often prove so troublesome.
Gum Arabick yields one Scruple of Cap. Mort. whereof, by the Taste, about ⅓ᵈ part is Salt.
Euphorbium yields one Drachm of Caput Mort. of which, by the strength of the Taste, two Scruples seem to be Salt. Which confirms a former conjecture[78] of its being an Alkaline Gumm.
Myrrh also yields a Drachm of Cap. Mort. and at least two Scruples of Salt. Of the Eleven, these two Gums have the greatest quantity of a fixed Alkaly.
Opium yields half a Drachm of Cap. Mort. whereof the one half is Salt.
Aloe yields a Drachm of Cap. Mort. conteining about one Scruple of Salt.
Scammony yields Two Scruples of Cap. Mort. of which, about half a Scruple is Salt.
Gutta Gamba yields but half a Scruple of Cap. Mort. of which four or five Grains are Salt.
So that considering the Dose of any Cathartick Gumm, the quantity of the Fixed Alkaly, is extream small with respect to the Volatile parts: In which, therefore, its Cathartick Power doth chiefly reside.
Yet none of the Cathartick Gumms are without some portion, more or less, of a Fixed Alkaly; though some of the rest are. Which seemeth to prove, That the Fixed it self, hath some Interest in the business of Purgation: as by being a Clog to the Volatile, and so preventing its being deleterious; or some other way. But the manner of their Operation will better be understood, when the Volatile Parts have likewise been examined.
It may also be of good import, to know, what different quantities of Salt, are afforded by the Tartars of all sorts of Wines. Whereby, partly, as well as by the quantity of the Tartar, we may be enabled the better to judge of the Nature of Wines.