Chapter XVIII: Part IV: Chap. I (4)

51. §. The _Stones_ already mentioned, (except the great _Stomach-stone_) are ordinarily generated in the bodies of _Animals_. I have one Instance more of some other _Stones_ which are extraordinary. In the City of _Hereford_ lives a Maid, who often voids these _Stones_, and in the space of some years last past, hath voided several pounds, of several _Colours_ and _Sizes_, not only _per vias urinarias_, but also by vomit, and by stool. The first mention made to me of them, was by Mr. _Diggs_, a worthy Gentleman of that City, as a thing that was there much wondred at. And some of them, upon my desire, were sent me by Mr. _Wellington_, an Apothecary in the same place. _I have tryed what several acid Menstruums will work upon them; and find, That with Oyl of Vitriol, and especially with Spirit of Nitre the great ones make a very quick and conspicuous Effervescence. But the small ones, neither the white, nor the grey, make any Bullition in the least:_ for in truth, they are no other but little _Pebbles_ and _Grit-stones_.

52. §. This being considerd, and the various _colours_ and _mixture_ of any one of the great _Stones_, being well observed; it seemeth plain, That although she be somewhat old (above thirty years) yet may she have a kind of μαλακία, or _diseased Appetite_ to _Stones_, _Bones_, _Wood-ashes_, _Tobacco-Pipes_, _Chalk_, and such like things; which sometimes swallowing in little _lumps_, sometimes grosly, or finely ground betwixt her teeth; they are in her _Stomach_ and _Bowels_, more or fewer of them, _cemented_ together, either with a _pituitous_, _bilious_, or some other more or less _glutinous substance_. And that by virtue also of the said _Cement_, or any of the said, or other like _alkalizate Bodies_, the greater _Stones_, which consist of those partly, do make an _Effervescence_ with _acid Liquors_. Thus far of _Instances_ upon the _parts_ of _Animals_. I shall close with some _Corollaries_ deduced from the whole.

53. §. And first, since we find, that amongst all the _Menstruums_ we have made use of, _Spirit_ of _Nitre_, or any very _Nitrous Spirit_, is the most _universal dissolver_ of all kinds of _Animal Bodies_; the _best dissolver_ of many others both _Vegetable_ and _Mineral_, and the _only dissolver_ of some: Hence it is probable, That the great _stomachick Menstruum_, which either _dissolves_, or _opens_ almost all _Bodies_ which come into the _Stomach_, is a kind of _Nitrous Spirit_.

54. §. Again, _Spirit_ of _Nitre_ being a _subalkaline Acid_, and working more evidently upon _Animal bodies_, than other _simpler Acids_ do, which yet are as _strong_; It hence follows, That most of the _Salts_ of _Animals_ are _subacid Alkalies_. How far this _conclusion_ may further instruct us, I shall have occasion to shew in another _Discourse_.

55. §. Lastly, there being so many, say twenty or thirty _degrees_, from the _slowest_ to the most _vehement_, in the _Bullition_ of _mixed Bodies_; it seemeth, That _Fermentation_ it self, as to the _formal notion_ of it, is nothing else: or that from the common _Luctation_ of _mixed Bodies_ whereof we have now been speaking, it differs not _in specie_, but only in the manner of its _causation_, and in _degree_: the _Aer_, or some certain _Menstruum_ lodged therein, being of no greater _strength_, than to produce a _Bullition_ or _Luctation_ of that _low_ and _soft degree_, which we call _Fermentation_.

56. §. I have thus endeavoured to prove, by various _Instances_, how instructive this most easie, plain and simple _Method_ in the _Mixture_ of _Bodies_, may become to us: and that meerly by observing the _Luctations_ which thence arise betwixt them. How much more then, if a diligent remarque be made of all those various _Colours_, _Smells_, _Tastes_, _Consistencies_, and other _Mutations_ thereupon emergent?

AN

ESSAY

OF THE

Various Proportions

Wherein the

LIXIVIAL SALT

Is found in

PLANTS.

Read before the _Royal Society_, _March_, 1676.

CHAP. I.

_Of the QUANTITIES afforded by several_ Plants
_calcined in gross._

IT is the part of a _Physician_, knowingly and artificially to use and govern _Nature_. And therefore by every likely _Method_, to inspect the _State_ and _Properties_ of all sorts of _Bodies_. One _Method_, is that I have taken in the foregoing _Experiments_; _sc._ by mixing them with several _Menstruums_ or _Liquors_: whereby we may be assisted to judge, both of the _Kinds_ and the _Proportions_ of _Principles_ in any _Body_; and of the manner of their _Mixture_ in the same.

Another is by _Calcining_ them; or, as it were, by _mixing_ them with the _Fire_, a potent and almost universal _Menstruum_. I shall here only set down some _Tryals_ for an _Essay_, upon _Plants_; chiefly noting, The different _Proportions_ of their _Lixivial Salts_. Of these _Tryals_, some were made upon the whole _Plant_, or some _Portion_ of it wherein several _Parts_ are mixed together: And others, upon some one _Part_ of a _Plant_ distinct from the rest. All of them answering to such _Queries_, as may seem proper to be proposed.

Query 1. As first, _Whether Trees or Herbs and Bushes, quantity for quantity_ & cæteris paribus, _yield the most Lixivial Salt?_

For this I took _Ash-Barque_ and _Rosemary_ of each ℔j. The latter yielded 5 _Scruples_; the former but 32 _Grains_; which is three times less. I took also the same quantity of the _Barque_ of _Black-Thorn_, and of _Agrimony_. The latter yielded 5 _Scruples_ and 6 _Grains_; the former, not above 1 _Scruple_ and 5 _Grains_; which is four times less.

Although the _Barque_ of a _Tree_ be compounded of _Pithy_ and _Lignous Parts_; yet to answer the _Query_ exactly, the _Wood_ of these _Trees_ should be taken with the _Barque_, that there may be some portion of every _Part_ of the _Tree_, as well as of the _Herb_.

But thus far the _Experiment_ is _conclusive_, That the same quantity of _Lixivial Salt_, doth not always follow the same _Generical Tast_. For the _Barque_ of _Ash_ and _Rosemary_, are both equally _Bitter_; and the _Barque_ of _Black-Thorn_ and _Agrimony_ are both _Astringent_ and _Bitter_.

Quer. 2. _Whether any Plant growing in a Garden or the Field, doth not yield a lesser quantity of Lixivial Salt, than another of the same kindred growing on the Sea-Coast; and with what difference?_

For this, I took _Garden_ and _Sea-Scurvygrass_, of each ℔j. The former yields 2 _Drachms_ and 1 _Scruple_; the latter, being well washed, 9 _Drachms_, which is more than 4 times as much. The like may be tryed upon others.

Quer. 3. _Whether the same Specifick Plant affords more Lixivial Salt, being only dryed, and then calcin’d, or after it hath first been distilled, it is then dryed and calcin’d?_

For this, was taken ℔j of _Mint_ only dryed and then calcin’d; and another first distilled. The former yielded ½ an Ounce and ½ a Drachm of _Salt_; the latter, 5 Drachms and a Scruple; which is almost ⅕ᵗʰ more. This also should be tryed on other _Plants_.

Quer. 4. _How far the proportion follows the different Tasts of Plants?_ The first Experiment, relates to the same _Tast_ in several _Plants_; this, to several Tasts. And so,

Of _Majorane_, which is _Aromatick_, ℔j affords but one Scruple of _Lixivial Salt_; which is but the 384ᵗʰ part of the whole pound.

Of _Oak-Barque_ which is _Astringent_, ℔j yields ½ a Drachm of _Salt_; or the 256ᵗʰ part of the whole.

Of _Liquirish_, which is sweet, ℔j yields about the same quantity. But _Anise Seeds_ ℔j yields 2 Scruples or a 192ᵈ part.

Of _Sorrel_, which is sower, ℔j yields one Drachm, or the 128ᵗʰ part.

Of _Garden Scurvygrass_, which is _Hot_, ℔j yields 2 Drachms and ½ a Scruple; or the 59ᵗʰ part.

Of _Mint_, which is _Hot_ and _Bitter_, ℔j yields 5 Drachms and a Scruple, or the 24ᵗʰ part.

Of _Sea Scurvygrass_, which is _Salt_, ℔j yields 9 Drachms and a Scruple or 28 Scruples; which is near 1/13ᵗʰ part of the whole. A greater proportion of _Salt_, than in any other _Plant_ upon which I have hitherto made Tryal: Or even in _Tartar_ it self. Yet is it not a _Marine_, but true _Lixivial Salt_: as is evident, both from its _Taste_; and in that it maketh an _Effervescence_ with _Spirit_ of _Salt_; which _Sea-Salt_ will not do.

For the Experiment to be fully adequate to the _Query_; the _Tryals_ should be made, either all on _Trees_, or all on _Herbs_; all on _Roots_, or all on _Stalks_, &c. Yet thus much is evident, That _Sorrel_ yields Thrice as much as _Majorane_; _Sea-Scurvygrass_, Eight and Twenty times as much: _Mint_, Five times as much as _Sorrel_; and Sixteen times as much _Majorane_, &c.

Quer. 5. _How far the Proportion follows the Faculties of Plants?_ And so, it appears, that

_Majorane_, a _Cephalick_, hath a greater _Proportion_ of _Volatile Parts_, than any of the _Plants_ above mentioned, and so far, is more agreeable to the _Animal Spirits_, and _Genus Nervosum_.

_Agrimony_,[76] an _Aperient_, yields above Five times as much _Lixivial Salt_, as _Majorane_. Yet much less than many other opening _Plants_ which are stronger.

[76] _Quer. 1._

_Mugwort_ (℔j) yields two Drachms and two Scruples; or above half as much more as _Agrimony_. So that this _Plant_, though it hath no considerable _Taste_, and in that respect promiseth but little; yet yielding a good quantity of _Lixivial Salt_, seems no contemptible _Medicine_ to subdue those _Acidities_ which either by causing _Obstructions_, or immoderate _Fermentations_, frequently disorder the _Female Sex_.

_Mint_, yieldeth still a greater quantity; and is therefore, partly for the same cause so excellent a _Stomachick_: And _Rosemary_,[77] which is appropriated both to the _Head_ and _Stomach_, yieldeth a midle quantity of _Salt_; more than the chief _Cephalicks_, and less than the chief _Stomachicks_.

[77] _Quer. 1._

_Common Mallow_ (℔j) yields 5 Drachms and 2 Scruples. _i. e._ the 23ᵈ part of the whole. So that this _Plant_, though of a very mild _Taste_, yet yields more _Salt_ than _Mint_ it self a _Bitter Plant_. Whereby it no longer seems strange, that a _Plant_ of so soft a _Taste_, should be very _Diuretick_, and so evidently affect the _Reins_.

_Rhubarb_ (2 Ounces) yieldeth scarce any fixed _Salt_, so for as can be judged by the _Taste_ of the _Ashes_, not more than a Grain or two. So that its _Salt_ is, in a manner, wholly volatile; and thereby apter to operate upon the _Bilious_ parts of the _Blood_; which contein a far greater proportion of _Volatile Salt_, than do the _Serous_.

Of the _Caput Mortuum_ or meer _Earth_, it is observable, that it was near ½ an Ounce or ¼ᵗʰ part of the whole; Which is almost Six times as much as the _Caput Mortuum_ of _Common Dock_: and much more than that of any other _Root_ I have yet calcin’d. Whereby it seemeth probable that _Rhubarb_ looseth much of its _Volatile Part_, and therefore of its _Virtue_, before it comes to our _Shops_.

_Sena_ (℔j) yields 4 Scruples and ½ of _Salt_; or the 85ᵗʰ part.

_Jalap_ (℔j) yields but one Drachm and 15 Grains, or 102ᵈ part.

_Colocynthis_ (℔j of the _Pulp_) yields an Ounce and half of _Caput Mortuum_, which is almost all _Salt_. Yet allow half an Ounce of the _Salt_, and _Earth_ to be wasted in filtring &c. the remaining Ounce is no less than 1/16ᵗʰ part of the whole. Which is more than in any of the above named _Plants_, except the _Sea-Scurvygrass_.

CHAP. II.

_Of the QUANTITIES afforded by the_ Parts _of several_
Plants _distinctly calcin’d._

I 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_.

[78] Of the _Luctation_ of _Bodies_, _Ch. 1._

_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_.

A

DISCOURSE

Concerning the

ESSENTIAL and MARINE

Salts of Plants.

Read before the _Royal Society_, _December 21,
1676_.

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.

SOMETIME 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_.

CHAP. II.

_Wherein is shewed, That the said ESSENTIAL and MARINE_ Salts _of_
Plants _are both of different Sorts._

HAVING made the Experiment, that both an _Essential_ and _Marine Salt_ may be produced out of the _Lixivial Salt_ of a _Plant_. I thought it probable, that neither the one nor the other, was always the same, but that as they had their general properties which made them to be of two general kinds; so they might have some special property, for the distinguishing of each kind into several Sorts. And withall, that in a warmer season, than before taken, the _Tryal_ hereof might be finished in a shorter time.

2. §. For the making of which, I conceived it requisite to remove an Opinion which seemed to lye in my way; _sc._ That there is little or no difference between the several _Lixivial Salts_ of _Plants_, as some Learned men have thought. But either there is a difference, or not: if not, it should be proved: and if there be, it should then be justly stated, what that difference is. For the doing of which, I chose this _Method_. I took an equal quantity of the whitest and purest _Salts_ of divers _Plants_, all made by an equal degree of _Calcination_; and dissolved them all severally in an equal quantity of water. And pouring likewise an equal quantity, as about 10 or 12 drops of each into a spoon, I tasted them severally. Whereby it was very evident, that they were not all of one _Tast_, but of very different ones, both as to strength and kind: and therefore different in Nature also. The _Salts_ I made tryal of were those of _Sorrel_, _Anise_, _Wormwood_, _Mallow_, _Ash_, _Tartar_ and others: and upon half a Drachm of each I poured ℥ijß of water. The _Solutions_ are here present to be tasted. By which the differences will easily be observed, and particularly that the _Salt_ of _Wormwood_ or _Scurvygrass_, is almost as strong again as the _Salt_ of _Anise_, or _Sorrel_: and that the _Salt_ of _Ash_ is above twice as strong, and that of _Tartar_ above thrice as strong, as that of _Sorrel_, and almost thrice as strong as that of _Wormwood_ or _Scurvygrass_. So that he who shall give half a Scruple, suppose of _Salt_ of _Tartar_; instead of half a Scruple of _Salt_ of _Wormwood_, or other like _Salt_; he may as well give a Scruple of _Rosin_ of _Jalap_, for a Scruple of the powder, or almost three Drachms of _Rhubarb_, or other like _Purge_, instead of one. And the like is to be said of other _Lixivial Salts_ in their degrees.

3. §. Having observed thus much, I proceeded to repeat the former Experiment, with some of the aforesaid, and some other _Vegetable Salts_, the best calcin’d, and the purest, that could be made for this purpose, being these Six _Salts_, _sc._ of _Rosemary_, _Garden Scurvygrass_, _Black Thorn_, _Common Wormwood_, _Ash_, and _Tartar_. All which dissolved severally in fair water, I exposed in a Chamber window, and not in Winter, as before, but in the heat of Summer, _sc._ on the 19 of _July_, to evaporate of themselves.

4. §. The Effect was, That the third day after their being exposed, the _Essential Crystals_ began to shoot in three of the _Solutions_, _sc._ in that of _Rosemary_, of _Garden Scurvygrass_, and of _Black Thorn_. On the fourth day, in that of _Wormwood_. On the fifth day, in that of _Ash_. In that of _Tartar_, not at all.

5. §. These _Essential Crystals_ began, in all, to shoot at the top, and then to fall to the bottome; as in the Experiment before. But as there was very little of the _white Sedement_ before mentioned, that preceded; So no _Scum_ or _Cremor_ at all. Which although a more perfect _Calcination_, it seems, did here almost prevent; yet did not in the least destroy the aforesaid _Essential Salt_, but rather make way for its more speedy and copious _Production_: exhibiting likewise a distinct _Species_ in several of the _Solutions_.

6. §. For first, the _Crystals_ of _Rosemary_ (the largest of them) were about the bigness of a _Rice-Corn_. In _Figure_ almost like a _Tip-Cat_, which Boys play with, split down the midle. Each _Tip_ being cut into 5 sides all ending in a poynt: ♦ _Tab. 83._ ♦ the midle part divided into 7, all drawn by parallel _Lines_; the topmost with the lowermost but one, on each side, being three exact _Squares_.

7. §. The _Crystals_ of _Black Thorn_ are most of them poynted with just six sides of Equal _Measure_: very like to the shooting of true _Crystal_ it self. ♦ _Tab. 83._ ♦ From the topmost of which six Sides, a _Line_ being drawn out, runs parallel to a broad _Base_, whereon each _Crystal_ stands. So that they are in some sort of a _Rhomboid Figure_.

8. §. The _Crystals_ of _Scurvygrass_ have also a very elegant and regular _Figure_, which is in a manner compounded of the two former now described. But they are nothing near so bigg, the largest of them, being no biger than a _Grain_ of that which we call _Pearl Barley_.

9. §. The _Crystals_ of _Wormwood_ have also very many of them a regular _Figure_; but quite different from that of the _Crystals_ before mentioned; each _Crystal_ being a little _Cylinder_, saving that it is constantly somewhat smaller at one end, than the other: as it were one half of a _Rowling-pin_. ♦ _Tab. 83._ ♦ And not evenly _Circular_, but cut out by Six _Sides_ of equal _Measure_: almost as in the _Crystal_ of _Nitre_. So that contrary to what is seen in the forementioned _Crystals_, the ends of these of _Wormwood_ are not poynted, but _flat_; and cut at _Right Angles_ with the _Sides_.

10. §. The _Crystals_ of _Ash_, though by their properties they appear likewise to be _Essential_; yet are nothing near so regularly figur’d, as all the forementioned.

11. §. The _Colour_ also of the said _Crystals_ is somewhat different: Those of _Ash_ being of a _brown_ transparency, almost like those of _Firne_. Those of _Wormwood_ being also _brownish_, but _paler_. Those of _Rosemary_ and _Scurvygrass_ having some little _Tincture_, yet very _clear_. But those of _Black Thorn_ without the least _Tincture_, and as _clear_ as _Crystal_ it self.

12. §. None of these _Essential Crystals_ have any hot fiery _Taste_, but are very _mild_, and sensibly _Bitter_; especially, about the _Root_ of the _Tongue_: as is also observable of some _Plants_ hereafter mentioned, in speaking of the different _Tastes_ of _Plants_.

13. §. _Oyl_ of _Vitriol_ droped upon these _Crystals_ doth not affect them in the least: yet droped into the several _Solutions_ out of which the _Crystals_ are produced, immediately causeth a great _Effervescence_.

14. §. Of the _Solutions_ above named, that, of _Salt_ of _Tartar_ was the 6ᵗʰ. Whereof it is remarquable, That having waited several Months together, I could not observe the least _Essential Salt_ to be therein produced in all that time. Whether there be any other _Vegetable Salts_, besides this of _Tartar_, which will not yield the _Essential_ above described, I have not yet experimented.

15. §. In the mean time, from the _Premises_ it is very probable, that most of them afford more or fewer of the said _Crystals_. In regard they are _Plants_ of a very different kind, which I made tryal upon: as _Garden Scurvygrass_, very _Hot_; _Rosemary_, very _Aromatick_. _Wormwood_ very _Bitter_; _Black Thorn_, _Astringent_ and _Sower_. And it is also plain, That the said _Essential Salts_ contained in the _Lixivial_, are not altogether one and the same, but of divers Sorts.

16. §. ABOUT 7 or 8 days after the _Essential Crystals_ were produced; the _Marine Salt_ did also begin to shoot; first in _Rosemary_; quickly after, in _Scurvygrass_; Next, in _Black Thorn_ and _Wormwood_, _sc._ after the space of a week or 10 days more. And in all of them with some difference of _Size_ and _Figure_.

17. §. The plainest of all, was that produced out of the _Salt_ of _Black Thorn_, consisting for the most part of very small _Crystals_, not above the 15ᵗʰ of an Inch square, as also _thin_, shaped like a _Duch Tile_ used for _Chimnies_. Many others were very _thick_, and near to a _Cube_. ♦ _Tab. 83._ ♦ Most of which were a little hollowed in the midle, like a grinding _Marble_ or _Salt-Celler_; and the hollow bounded by 4 plain and equal _Sides_, all descending a little towards the _Centre_; and measured by two cross _Lines_, which staid upon the four _Angles_ of the _Square_, and so cut one the other at _Right Angles_. Both which _Properties_ are likewise usually seen in the _Crystals_ of _Common Salt_.

18. §. In _Wormwood_, many of these _Crystals_, besides the plain ones, were figur’d crossways like a _Dagger-Hilt_. ♦ _Tab. 83._ ♦ Which was sometimes naked, and sometimes inclosed in a square and almost _Cubical Box_. Many others were figur’d into _Sprigs_ made up of four chief _Branches_ standing crosswise, and those _subbranched_; and all the _Branches_ made up of little square _Crystals_, clustered together in that _Figure_. The _Sprigy Figure_ of these _Crystals_ is not accidental, but hath constantly come after they had been three times dissolved, and the _Solution_ exposed to evaporate.

19. §. The _Marine Salt_ of _Rosemary_ hath also some variety. For besides the plain ones above described, there are some thick _Squares_, ♦ _Tab. 83._ ♦ which have also a square hollow descending by five, six, or seven narrow steps, towards the _Centre_; being in _Figure_, saving these _Steps_, somewhat like the _Hoper_ in a _Mill_.

20. §. Upon a second _Solution_ of the same _Salt_, there shoots another sort of square; which is not plain on the edges, as the above-named, ♦ _Tab. 83._ ♦ but scalloped or florid all round about, not unlike the _Leaves_ of some _Plants_.

21. §. The _Crystals_ of _Marine Salt_ of _Scurvygrass_ are somewhat like to those of _Rosemary_ now described.

22. §. As for the _Lixivial Salts_ of _Ash_ and _Tartar_, though in a Month or Five Weeks Space, they yield some _Crystals_ of very clear _Salt_: yet of _Marine Salt_ neither of them yieldeth the least particle. So that of these Six _Lixivial Salts_, _sc._ of _Rosemary_, _Scurvygrass_, _Black Thorn_, _Wormwood_, _Ash_ and _Tartar_, all, but that of _Tartar_, yielded an _Essential Salt_. And all, but those of _Ash_ and _Tartar_, yielded a _Marine_, such as is above described. All which _Salts_ both _Essential_ and _Marine_, together with their _Models_, made of _white Alabastre_, I have here ready to be seen.

23. §. Of those that yield these _Salts_, or either of them, it is further to be noted, That there is a considerable difference in the _Proportion_ or _Quantities_ which they yield. The _Rosemary_ yields store both of _Essential_ and _Marine_, but more _Essential_. _Wormwood_ and _Scurvygrass_ more _Marine_. _Black Thorn_ less of Either. The _Ash_ no _Marine_, and the _Tartar_ neither the _Essential_ nor _Marine_, as hath been said.

24. §. From what hath been said, I deduce only at present these Three _Corollaies_. _First_, That a _Lixivial Salt_, is not only a compounded Body _sc._ of _Salt_, _Sulphur_, _Aer_ and _Earth_; but even a _Compounded Salt_, containing both a _Vegetable Nitre_, and a true _Sea Salt_.

25. §. _Secondly_, That the _Exposing_ of _Bodies_, in the manner above shewed, may justly be accounted one _Part_ of _Chymistry_ hitherto _Deficient_, and much farther to be improved for the _Discovery_ of the _Nature_ of _Bodies_. For as _Nature_ chiefly compoundeth _Bodies_ by _Digesting_ them, and so either shutting out or keeping in the _Aer_: So she _Dissolveth_ them by _Exposing_, and so neither shutting in the _Aer_, nor keeping it out, but leaving it free to come and go; and thereby to bring, and carry off whatsoever is necessary for the _Separation_ or _Solution_ of _Bodies_. For the _Sea_ it self (to confine the similitude to our present case) is but as a _Great Pan_, wherein all kinds of bodies being long exposed, are throughly resolved, ultimately yielding from the rest of their _visible Principles_, that which we call _Sea Salt_.

26. §. _Lastly_, if by _Exposing_ and _Dissolving_ we can make one _Salt_; then by _Compounding_ and _Digesting_ we may make another, yea any other _Salt_; either a _Fixed_ of a _Volatile_, or a _Volatile_ of a _Fixed_. That is to say, a _Volatile Salt_ may be so separated from other _Bodies_, as to become _Fixed_; or a _Fixed Salt_ may be so _mixed_ with other _Bodies_ as to become _Volatile_. For that any _Salt_ should of it self become _Fixed_ or _Volatile_, is a _Fixion_ not grounded upon _Experiment_.

27. §. As for the _Virtue_ of the _Essential Salts_ above described, I believe they will be found upon tryal, not contemptible in some Cases. For which amongst other reasons, I have been the more punctual in relating the manner of their _Generation_; that others also may have the opportunity of making proof hereof.

28. §. When I made the _Experiments_ for this and the foregoing _Discourse_, not having so good conveniency at home for making the _Salts_ I used: I procured them all (except that of _Firne_, which I made my self) to be purposely prepared by Mr. _John Blackstone_ a _London Apothecary_, who assured me of his great care herein; and particularly, that he added no _Nitre_ to whiten any of the _Salts_ with, as is commonly done for that of _Tartar_.

I do declare, That all the _Lixivial Salts_ mentioned
in this and the foregoing _Discourse_ except that of
_Firne_, were faithfully prepared by me

_John Blackstone._

A

DISCOURSE

OF THE

COLOURS

OF

PLANTS.

Read before the _Royal Society_, _May 3. 1677_.

CHAP. I.

_Of the COLOURS of_ Plants _in their Natural
Estate._

HAVING formerly made some _Observations_ of the _Colours_ of _Plants_; ♦ _Idea, §. 27._ and _Anat._ of _R. P. 2. §. 65,_ &c. ♦ I shall now crave leave to add some more to them of the like _Nature_. None of which, nor any of the _Conclusions_ thence deduced, will, if duly considered, appear contrary to the _Hypothesis_ and _Experiments_ of Mr. _Boyle_, Mr. _Des Cartes_, Mr. _Hook_, Mr. _Newton_, or any other, concerning _Colours_. As not having respect to the _Colours_ of all _Bodies_ in general. Nor to the _Body_ of _Colour_, which is _Light_; Nor to the formal notion of _Colours_ (_ad extra_) as the _Rays_ of _Light_ are moved or mixed: But to those _Materials_, which are principally necessary to their _Production_ in _Plants_. Concerning which, the present _Discourse_ shall be reduced to these Three general _Heads_, _scil._

2. §. _First_, Of those several _Colours_, which appear in _Plants_ in their _Natural Estate_.

3. §. _Secondly_, As they appear upon the _Infusion_ of _Plants_ into several Sorts of _Liquors_.

4. §. _Thirdly_, As upon the _Mixture_ of those _Infusions_, or of any one of them with some other _Liquor_, or other _Body_.

5. §. As they appear in the _Plants_ themselves, it may be observed in the first place, That there is a far less variety in the _Colours_ of _Roots_, than of the other _Parts_: the _Parenchyma_ being, within the _Skin_, usually _White_, sometimes _Yellow_, rarely _Red_. The _Cause_ hereof being, for that they are kept, by the _Earth_, from a free and open _Aer_; which concurreth with the _Juyces_ of the several _Parts_, to the _Production_ of their several _Colours_. And therefore the upper parts of _Roots_, when they happen to stand naked above the Ground, are often deyed with several _Colours_: so the tops of _Sorrel Roots_ will turn _Red_, those of _Mullen_, _Turneps_ and _Radishes_, will turn _purple_, and many others _green_. Whereas those parts of the same _Roots_ which lie more under Ground, are commonly _White_.

6. §. As _Roots_ are more commonly _White_; so the _Leaves_, _Green_. Which _Colour_ is so proper to them, that many _Leaves_, as those of _Sage_, the young _Sprouts_ of St. _Johns-wort_, and others, which are _Redish_ when in the _Bud_; upon their full _Growth_, acquire a perfect _Green_.

7. §. The _Cause_ of this _Colour_, is the _action_ of the _Aer_, both from within, and from without the _Plant_, upon the _Juyces_ thereof, whereby it strikes them into that _Colour_.

8. §. By the _Aer_ from without, I mean that which surrounds the _Body_ of the _Plant_: which is the Cause of its _Greeness_, not meerly as it is contiguous to it, but as it penetrates through the _Pores_ of the _Skin_, thereinto; and so mixing with the _Juyces_ thereof, plainly deys or strikes them into a _Green_.

9. §. By the _Aer_ from within, I mean, that which entring, together with the _Aliment_, at the _Root_, thence ascends by the _Aer-Vessels_, into the _Trunk_ and _Leaves_, and is there transfused into all the several _Juyces_, thereby likewise concurring to their _Verdure_. Whence it is, that the _Parts_ of _Plants_ which lie under _Water_, are _Green_, as well as those which stand above it; because, though the ambient _Aer_, conteined in the _Water_ be but little, yet the want of it is compensated, by that which ascends from the _Root_.

10. §. And therefore it is observable, that the _Stalks_ of _Marsh-Mallow_, and some other _Plants_, being cut transversly, though the _Parenchyma_ in the _Barque_ be _white_, yet the _Sap-Vessels_ which lie within that _Parenchyma_, are as _Green_ as the _Skin_ it self; _scil._ because they stand close to the _Aer-Vessels_. The _Parenchyma_, I say, which is intercepted from the _Aer_, without, by the _Skin_; and from the _Aer_ within, by the _Sap Vessels_, is _white_: but the _Skin_, which is exposed to the _Aer_ without, and the _Sap-Vessels_ which are next neighbours to that within, are both equally _Green_. So likewise if a _Carrot_ be plucked up, and suffered to lie sometime in the open _Aer_; that part which standeth in and near the _Centre_, amongst the _Aer-Vessels_, will become _Green_ as well as the _Skin_, all the other _Parts_ continuing of a _Redish Yellow_, as before. The _Aer_ therefore, both from without, and from within the _Plant_, together with the _Juyces_ of the _Plant_, are all the concurrent _Causes_ of its _Verdure_.

11. §. BUT how doth the _Aer_ concur to the _Greeness_ of _Plants_? I answer; Not as it is meerly either _cold_ or _dry_, or _moist_, nor yet _quatenus Aer_; but as it is a mixed, and particularly, a _Saline Body_: that is, as there is a considerable quantity of _Saline Parts_ mixed with those which are properly _Aereal_. It being plain from manifold Experience; That the several kinds of _Salts_, are the grand _Agents_ in the _Variation_ of _Colours_. So that, to speak strictly, although _Sulphur_ be indeed the _Female_, or _Materia substrata_, of all _Colours_; yet _Salt_ is the _Male_ or _Prime Agent_, by which the _Sulphur_ is determined to the _Production_ of one _Colour_, and not of another.

12. §. If then it be the _Aer_ mixed with the _Juyces_ of a _Plant_, and the _Salt_ of the _Aer_, that makes it _Green_; It may further be asked, what kind of _Salt_? But this is more hard to judge of. Yet it seemeth, that it is not an _Acid_, but a _Subalkaline Salt_; or at least some _Salt_ which is different from a simple _Acid_, and hath an _Affinity_ with _Alkalies_.

13. §. One reason why I so judge, is, Because that although all _Plants_ yield an _Alkaly_, or other _Salt_ different from an _Acid_, and some in good quantity; yet in most _Plants_, the _Prædominant Principle_ is an _Acid_. So that the _Supply_ of an _Acid Principle_ from the _Aer_, for the _Production_ of a _Green Colour_, as it would be superfluous; So also ineffectual: a different _Principle_ being requisite to the striking of this, together with the _Sulphur_, into a _Green Colour_.

14. §. I suppose therefore, That not only _Green_, but all the _Colours_ of _Plants_, are a kind of _Precipitate_, resulting from the concurrence of the _Saline Parts_ of the _Aer_, with the _Saline_ and _Sulphurious Parts_ of the _Plant_; and that the _Subalkaline_, or other like _Saline Part_ of the _Aer_, is concurrent with the _Acid_ and _Sulphurious Parts_ of _Plants_, for the _Production_ of their _Verdure_; that is, as they strike altogether into a _Green Precipitate_. Which also seemeth to be confirmed by divers _Experiments_ hereafter mentioned.

15. §. THE _Colours_ of _Flowers_ are various; differing therein not only from the _Leaf_, but one from another. Yet all seem to depend upon the general _Causes_ aforesaid. And therefore the _Colours_ of _Flowers_, as well as of _Leaves_, to result not solely from the _Contents_ of the _Plant_, but from the concurrence likewise of the _ambient Aer_. Hence it is, that as they gradually open, and are exposed to the _Aer_, they still either acquire, or change their _Colour_: no _Flower_ having its proper _Colour_ in the _Bud_, (though it be then perfectly formed) but only when it is expanded. So the _Purple Flower_ of _Stock-July Flowers_, while they are in the _Bud_, are _white_, or _pale_. So _Batchelors Buttons_, _Blew Bottle_, _Poppy_, _Red Daisies_, and many others, though of divers _Colours_ when blown, yet are all _white_ in the _Bud_. And many _Flowers_ do thus change their _Colours_ thrice successively; as the youngest _Buds_ of _Ladys-Lookinglass_, _Bugloss_ and the like, are all white, the larger _Buds_ are _purple_ or _murrey_, and the open _Flowers_, _blew_: according as they come still neerer, and are longer exposed, to the _Aer_.

16. §. But if the _Colour_ of the _Flower_ dependeth on the _ambient Aer_; it may be asked: How it comes to pass then, that this _Colour_ is various, and not one, and that one, a _Green_? that is to say that all _Flowers_ are not _Green_, as well as the _Leaves_? In answer to this Three things are to be premised.

17. §. _First_, What was said before, is to be remembred, that here the _Aer_ is not a solitary, but concurrent _Cause_. So that besides the _Efficacy_ of this, we are to consider that of the several parts of the _Plant_, by which the _Contents_ both _Aereal_ and _Liquid_ are supplied to the _Flower_.

18. §. _Secondly_, That in the _Lymphæducts_ of a _Plant_, _Sulphur_ is the _predominant Principle_, and much more abounding than in any other _part_ of a _Plant_, as also hath been formerly shewed.

19. §. _Thirdly_, That it appears, according to what we have observed in the _Anatomy_ of the _Flower_, That the quantity of _Lymphæducts_ with respect to the _Aer-Vessels_ is greater in the _Flower_ than in the _Leaf_.

20. §. It seemeth therefore, that the _Aer-Vessels_, and therefore the _Aer_, being _predominant_ in the _Leaf_; _Green_, is therein also the _predominant Colour_. I say _predominant_, because there are other _Colours_ lye vailed under the _Green_, even in the _Leafe_, as will hereafter appear more manifest.

21. §. On the contrary, the _Lymphæducts_, and therefore the _Sulphur_, being more, and the _Aer-Vessels_ and therefore the _Aer_, less, in the _Flower_ than in the _Leaf_; the _ambient Aer_ alone is not able to controle the _Sulphur_ so far, but that it generally carrys the greatest port in the _Production_ of the _Colour_. Yet in different degrees; For if the proportion betwixt the _Lymphæducts_ and the _Aer-Vessels_ be more equal, the _Flower_ is either _White_ or else _Yellow_, which latter _Colour_ is the next of kin to a _Green_. If the _Sulphur_ be somewhat _predominant_, the _Flower_ will shew it self _Red_ at first; but the _ambient Aer_ hath so much power upon it, as gradually to turn the _Red_ into a _Blew_. But if the _Sulphur_ be much _predominant_, then the _Acid_ of the _ambient Aer_ will heighten it to a fixed _Red_.

22. §. Hence it is, that _Yellows_ and _Greens_ are less alterable, upon the drying of _Plants_ than other _Colours_; _sc._ Because the _Aer_ being _predominant_ in their _Production_, they are the less lyable to suffer from it afterwards. Whereas _Reds_ and _Purples_, in the _Production_ whereof _Sulphur_ is _predominant_, are very changeable. So the _Red_ Flowers of _Lysimachia_, upon drying, turn _Purple_, and the young _purple Flowers_ of _Bugloss_ turn _Blew_. So likewise the _Purple_ of _Bilberries_, and the _Crimson_ of baked _Damascens_, both turn _Blew_. For being gathered, and so wanting a continued supply of fresh _Sulphur_, to bear up the _Colour_ against the force of the _Aer_; it strikes it down at last from _Red_ to _Purple_ or _Blew_. I conclude therefore, that one _Principal Cause_ of the _Variety_ of _Colours_ in the _Flower_, is the over proportion of the _Lympheducts_ to the _Aer-Vessels_, and therefore the dominion of the _Sulphur_ over the _Aer_, therein.

23. §. If it be objected, that the _Aer_ doth not deepen, but highten the _Colour_ of the _Blood_: I answer, _First_, That I am not now speaking of _Animal_, but of _Vegetable Bodies_; the same _Aer_ which hightens the _Colour_ of _Blood_ one way, may deepen that of a _Flower_, another: nay and may highten that of some _Flowers_ too, some other way.