Into an iron pot put the plant whose Salt you desire to obtain in the

manner of Tachenius, and set it over a fire, strong enough to make

its bottom red-hot; at the same time cover your plant with a plate of

iron, that may lie immediately upon it in the pot. The plant will grow

black, and smoke considerably; but will not flame, because it hath not

a sufficient communication with the air. The black smoke only will

escape through the interstice left between the side of the pot and the

rim of the plate; which, for that purpose, should be made so as not to

fit exactly into the pot. From time to time take up the iron plate,

stir the plant, and cover it again immediately, to prevent its taking

fire, or to smother it if it should happen to flame: go on thus till

the black smoke cease.

Then take off the iron plate: the upper part of the half-burnt plant

will take fire as soon as the air is admitted, consume gradually, and

be reduced to a white ash. Stir your matter with an iron wire, that the

undermost parts, which are still black, may be successively brought

uppermost, take fire, and burn to white ashes. Go on thus as long as

you perceive the least blackness remaining. After this, leave your

ashes some time longer on the fire; but stir them frequently, to the

end that, if any black particles should still be left, they may be

entirely consumed.

Your ashes being thus prepared, lixiviate them with seven times their

quantity of water, made to simmer over the fire, and keep stirring

it with an iron ladle. Then filter the liquor, and evaporate it to

dryness in an iron pot, stirring it incessantly towards the end, lest

the matter, when it grows stiff, should adhere too closely to the

vessel. When all the humidity is evaporated, you will have a Salt of a

darkish colour, and alkaline nature; which you may melt in a crucible,

and mould into cakes. This is the Fixed Salt of plants, prepared in the

manner of Tachenius.

_OBSERVATIONS._

The Fixed Salt obtained from plants in the manner invented by

Tachenius, and here described, is in many respects different from the

Caustic Fixed Alkali extracted out of the ashes of plants that have

been consumed by flaming in the open air. Tachenius's Salt is indeed

of an Alkaline nature; but much weaker than a pure Fixed Alkali. It is

not by far so caustic; it attracts the moisture of the air much more

feebly and slowly; it melts with a much smaller degree of heat; and it

doth not make so strong an effervescence with Acids. In short, if you

dissolve it in water, evaporate the solution to a pellicle, and set it

in a cool place, it will shoot into small crystals; which is not the

case with a pure Fixed Alkali.

These several different effects, which characterize Tachenius's Salt,

and distinguish it from the Caustic Fixed Alkali produced by burning a

plant in the open air, prove that it is not a pure Alkali, but combined

with certain substances that bring it nearer to the nature of a Neutral

Salt, and place it, as it were, in the mid-way between such a Salt and

a true Alkali. If we reflect on the manner in which it is produced, it

is easy to perceive what those substances are that must be combined

with it. It hath been shewn that plants, when analyzed, yield a great

deal of Oil and of Acid. When they are burnt in the open air, all their

Oil is dissipated in smoke, or consumed in flame. Great part of the

Acid is likewise dissipated, and the remainder combining with the Earth

of the plant forms a Fixed Alkali.

When the same plants are analyzed, by distilling them in close vessels,

the same principles are carried up by the action of the fire, forced

to separate from the fixed parts, and pass over into the receiver

in the form of vapours and of a liquid: but, when they are burnt in

the manner of Tachenius, the Acid and Oil of the plant, as fast as

they are expelled by the action of the fire, are repelled by the iron

cover, which, at the same time that it prevents the Oil from being

entirely consumed in flame, obliges these two substances to circulate,

reverberates them on the rest of the plant, and, in a manner, forces

them to re-unite, in part, with that from which they were just before

separated.

A considerable quantity, therefore, of the Oil and Acid of the plant,

must evidently combine, in this operation, with its Fixed Salt, as fast

as it is produced; and the properties above specified are owing to

these two substances. Tachenius's Salt is, therefore, a Fixed Alkali,

partly neutralized by some of the Acid of the plant, and rendered a

little saponaceous by a portion of its Oil; whence it is much milder

than a pure Fixed Alkali, and proper to be given internally, as an

excellent remedy in several disorders.

For the medicinal virtues of this Salt Mr. Boerhaave's Chymistry ought

to be consulted, as the author was a very good judge of such matters.

Tachenius's Salt may be converted into a Caustic Fixed Alkali, by

freeing it from the Acid and from the Oil to which its peculiar

properties are owing. For this purpose nothing more is requisite than

to calcine it for a long time in a crucible, stirring it frequently

with an iron wire, and taking care not to melt it, till it have

undergone the same changes, and successively acquired the same colours,

as our Fixed Alkali; and, when it becomes reddish, melting it and

keeping it in fusion for an hour or two.

Hitherto no sensible difference hath been observed between the Caustic

Fixed Alkalis obtained from different plants, when equally calcined;

except that those produced by Sea-plants have, as we said before, the

same properties as the Alkaline basis of Sea-salt. Much the same thing

may be said of the Fixed Salts obtained from plants by Tachenius's

method: for, though they be combined with a portion of the Acid and Oil

of the plant, yet, as these principles have-been exposed to the action

of a strong fire, they are exceedingly altered, and almost wholly

reduced to one and the same condition.

PROCESS III.

_To render Fixed Alkalis very caustic by means of Lime. The Caustic

Stone._

Take a lump of newly burnt quick-lime, that hath not yet begun to

flake in the air: put it into a stone pan, and cover it with twice

its weight of the unwashed ashes of some plant, that are full of the

Salt you design to render caustic. Pour on them a great quantity of

hot water; let them steep in it five or six hours, and then boil them

gently. Filter the liquor through a thick canvas bag, or through brown

filtering paper supported by a linen cloth.

Evaporate the filtered liquor in a copper bason set over the fire; and

there will remain a Salt, which must be put into a crucible set in

the fire. It will melt, and boil for some time; after which it will

be still, and look like an Oil, or melted Fat. When it comes to this

condition, pour it out on a very hot copper plate, and cut it into

oblong tapering slips, before it grow hard by cooling. Put these slips,

while they are still hot, into a very dry glass bottle, and seal it

hermetically. This is the _Caustic Stone_, or _common Caustic_.

_OBSERVATIONS._

The design of this operation is to combine with the Fixed Alkali all

the saline acrid parts of the quick-lime. This is to be effected only

by dispersing and diffusing both those substances in water, which is

the proper solvent of all saline matters. Seeing, therefore, we must

have an actual lixivium, it is needless to employ an Alkali already

prepared and separated from ashes; for which reason we directed ashes

that are still replete with Alkali to be used instead of a pure Alkali.

By this means two ends are answered at once: the Salt contained in

the ashes is extracted from them, and combined with the most acrid,

subtile, and saline parts of the lime.

The lye, when saturated with these two saline matters together, is

vastly more acrid and caustic than if it contained but one of the

two in a quantity equal to both. With this lye Soap is usually made;

because the acuated Alkali contained in it hath a much greater effect

on Oils than any other kind of Alkali. It also acts with incredible

violence on all animal matters; which it dissolves, divides, and, in

some measure, destroys, with surprising efficacy and quickness.

For this reason it is impossible to filter it through a woollen or

silken bag; for it will eat holes in them, or even reduce them to a

pap, almost as soon as it touches them. Besides, as the lye would

dissolve some part thereof, it would thence acquire a saponaceous

quality, and so lose much of its caustic nature. We must, therefore,

necessarily use a filter made of vegetable matters, which resist this

destroying Salt much better than animal matters.

An Alkali thus acuated by quick-lime attracts and retains humidity more

strongly than any other kind of Alkali, even the perfectest and best

calcined. For this reason it is almost impossible to dry it thoroughly

in the bason wherein you evaporate the lixivium.

To the moisture still left in it must be attributed its boiling when it

begins to melt in the crucible. When all the humidity is dissipated,

the fused Salt remains smooth and unruffled, like wax melted with a

gentle heat.

This caustic Salt is vastly more fusible than the common Alkalis. It

scarce grows red before it flows like wax. When it is once in quiet

fusion, all the humidity that occasioned the boiling observed at first

being dissipated, it is as caustic as it can be made. It is then time

to pour it out, and to cut it into long narrow sticks, fit for the use

of Surgeons, who apply it to eat away callosities and excrescences, and

to open tissues. On this account it is called the _Caustic

Stone_. The operation of this Salt is so quick, that, in a very short

time, it produces on the skin a sensation like that of fire.

As this Salt grows surprisingly soon moist in the air, and loses its

virtue when so moistened, it is necessary to shut it up, while it is

still hot, in a very dry bottle, which must be immediately stopped

with a glass stopple rubbed with emery, or else with a round cork and

then dipt in pitch. In spite of all these precautions, it can scarce

be kept five or six months in full vigour; especially if the bottle be

sometimes opened in the mean while. We shall not attempt to explain

here why an Alkali becomes so violently caustic by being combined with

quick-lime. This question seems to be one of the most subtile, and the

most difficult to answer, in all Chymistry. It depends on the cause of

the Alkaline properties of lime; and can hardly be resolved, till we

attain a further insight into the nature of that substance than we have

yet got.

PROCESS IV.

_The Analysis of Soot._

Take wood-soot from a chimney under which no animal matter hath been

dressed or burnt: put it into a glass retort set in a reverberating

furnace; lute on a receiver, and begin to distil with a degree of heat

somewhat less than that of boiling water. A considerable quantity of

limpid phlegm will come over. Keep the fire in the same degree as long

as any of this phlegm rises; but increase it when the drops begin to

come slow: and then there will ascend a good deal of a milky water.

When this water ceases to run, change the receiver, and increase your

fire a little: a yellow Volatile Salt will rise, and stick to the sides

of the receiver. The fire ought now to be very fierce, and, if so, will

force up at the same time a very thick black Oil. Let the vessels cool:

you will find a saline matter risen into the neck of the retort, which

could not pass over into the receiver: in the bottom of the retort will

be a _caput mortuum_, or black charred substance, the upper part of

which will be crusted over with a saline matter, like that in the neck

of the retort.

_OBSERVATIONS._

The preceding analysis shewed what principles are obtained from

vegetable substances without the aid of fire; those which the heat of

fire raises and carries over out of one close vessel into another;

and, lastly, those that continue fixed after the vegetable hath

been thoroughly charred, either in a close vessel, or in the open

air: nothing therefore remained, to finish the subject of vegetable

principles, but to examine those which fire raises, in the form of

vapours, smoke, and flame, from a vegetable matter burnt and consumed

in the open air. Every body knows that Soot consists only of these

principles, collected in the shafts of chimneys, which serve as

alembics for this sort of distillation in the open air. By analysing

Wood-soot, therefore, we shall discover the principles we are in

quest of. The process we have given for that purpose is taken from

Boerhaave's Chymistry, where we find it described with great exactness

and precision.

As we are at present inquiring into the nature of vegetables only,

it is evidently necessary that we chuse a Soot produced by burning

vegetables alone. Soot, though dry in appearance, contains nevertheless

much humidity, as appears from this analysis; seeing there comes over

at first a considerable quantity of phlegm, that doth not seem to be

impregnated with any principle, except perhaps an extremely subtile,

saline, and oily matter, that communicates to it a disagreeable smell,

from which it cannot by any means be entirely freed.

The white milky liquor, which follows this first phlegm, is still

water, but much, more impregnated with saline and oily parts than

the former. By its smell, which is exceeding quick and pungent, we

may judge it contains much Volatile Alkali; and accordingly, when

re-distilled by itself, it yields a Volatile Spirit, and a Volatile

Salt in a concrete form. With regard to its white colour, it is

occasioned by the oily parts which are diffused and suspended, but not

dissolved, in the water. When this second liquor is come off, there

ascends a Volatile Alkali in a dry form, and a very thick black Oil;

because there is not moisture enough left to dissolve these principles,

or rather to divide and disperse them.

The Volatile Alkali obtained from Soot is, in a double respect, the

product of the fire. In the first place, though it derives its origin

wholly from wood, or other vegetables, which, when distilled in close

vessels, yield no Volatile Alkali at all, yet it produces such a Salt

when analyzed in the present manner: whence it must be inferred, that

the principles of those vegetables are metamorphosed into a Volatile

Alkali, by being burnt in the open air, and sublimed in the form of

Soot. Secondly, though Soot when analyzed yields a great deal of this

Salt, yet this Salt doth not formally pre-exist therein; for it doth

not rise till after the phlegm, nor without a very considerable degree

of heat: therefore Soot contains only the materials necessary to form

this Salt; therefore the perfect combination of this Salt requires that

the force of fire be applied a second time; therefore it is, as was

said, doubly the product of the fire.

The saline matter which we find sublimed into the neck of the retort,

and which also forms the crust that covers the _caput mortuum_ of the

Soot, appears by all Chymical trials to be an Ammoniacal Salt; that

is, a Neutral Salt consisting of an Acid and a Volatile Alkali. This

Ammoniacal Salt rises only into the neck of the retort, and doth not

come over into the receiver: because it is but semi-volatile. We shall

treat more at large of the production of a Volatile Alkali, and of

this Ammoniacal Salt, when we come to the analysis of Animals, and the

article of Sal Ammoniac.

The charred matter that remains in the retort after distillation, being

burnt in the open air, is reduced to an exceeding fixed white earth.

As this fixed matter was part of that very Soot, which was sublimed to

a great height whilst the vegetable was burning; this is a proof of

what we advanced before, that the most fixed matters are capable of

sublimation, when united with volatile substances; especially when they

are exposed at the same time to the combined action of air and of fire.

CHAP. VIII.

_The_ ANALYSIS _of some particular_ SUBSTANCES _belonging to the_

VEGETABLE KINGDOM.

PROCESS I.

_Analysis of the natural Balsams: instanced in Turpentine._

Into a cucurbit put as much rain-water as will fill about a fourth

part of its cavity, and pour into it the Turpentine you intend to

analyze. Cover the cucurbit with its head, and lute it on with slips of

sized paper or wet bladder. Set your alembic in a sand-heat; lute on

a long-necked receiver; and give a gradual fire till the water in the

cucurbit boil. There will come over into the receiver a good deal of

phlegm, which, by little and little, will become more and more acid;

and at the same time there will rise a great quantity of an æthereal

Oil, extremely light, fluid, and as limpid and colourless as water.

When you observe that no more Oil comes off, unlute your vessels; and

in the receiver you will find an acidulated water, and the æthereal Oil

floating on it. These two liquors may be easily separated from each

other, by means of a glass funnel.

In the cucurbit will be left some of the water you put in, together

with the remainder of your turpentine; which, when cold, instead of

being fluid as it was before distillation, will be solid, and of the

consistence of a resin, and is then called _Rosin_.

Put this residuum into a glass retort, and distil it in a reverberatory

with a naked fire, gradually increased according to the general rule

for all distillations. At first, with a degree of heat a little greater

than that of boiling water, you will see two liquors come over into the

recipient; one of which will be aqueous and acid, the other will be a

transparent, limpid, yellowish Oil, floating on the acid liquor.

Continue your distillation, increasing your fire from time to time, by

slow degrees. These two liquors will continue to come off together:

and the nearer the operation draws to its end, the more acid will

the aqueous liquor become, and the thicker and deeper coloured will

the Oil grow. At last the Oil will be very thick, and of a deep

reddish-yellow colour. When nothing more ascends, unlute your vessels:

in the retort you will find only a very small quantity of a charred,

light, friable substance.

_OBSERVATIONS._

All Natural Balsams, as well as Turpentine, are oily, aromatic matters,

which flow in great quantities from the trees containing them, either

spontaneously, or through incisions made on purpose. As these matters

have a strong scent, it is not surprising that they should greatly

abound with Essential Oils. They may even be considered as Essential

Oils, that naturally, and of their own accord, separate from the

vegetables in which they exist.

Indeed these Natural Balsams differ from the Essential Oils obtained

out of plants by distillation, in this alone, that the former contain

a greater proportion of Acid; and, for that reason, are thicker than

Essential Oils distilled with the heat of boiling water. But it hath

been shewn, that these same distilled Essential Oils, though ever

so fluid and light at first, gradually lose their tenuity as they

grow old, and at last become considerably thick. On that occasion we

observed that they are thus changed, because the lightest, most fluid,

and least acid parts, are little by little dissipated and evaporated;

so that at last there remains only the thickest and heaviest part,

which owes these qualities to the Acid wherewith it is over-dosed.

Hence it follows, that Natural Balsams, and Essential Oils grown

thick with age, are exactly one and the same thing. Accordingly we

see that fire and distillation produce the same effects on both. The

rectification of an Essential Oil, thickened by keeping, is nothing but

a decomposition thereof, by separating, with the heat of boiling water,

all those parts that are light enough to rise with that degree of heat,

from what is so loaded with Acid as to remain fixed therein.

This operation is therefore precisely the same as our first

distillation of Balsams with the heat of boiling water, by which the

Essential Oil contained in them is drawn off. The residues of these

two operations are also the same: each of them is a thick Oil, loaded

with Acid, that is wholly, or nearly, deprived of the principle of

odour peculiar to the original vegetable, and requires a degree of

heat greater than that of boiling water to decompose it, by separating

part of the Acid from the Oil; which will be rendered still the more

fluid, the more the thickening Acid is separated from it by repeated

distillations.

The newer Natural Balsams are, the thinner they are, and the more

Essential Oil do they yield; and this Essential Oil, like all others,

grows thick in time, and at last turns again to an actual Balsam.

These Balsams, by being long exposed to the heat of the sun, acquire

such a consistence as to become solid. They then take another name,

and are called _Resins_. Resins yield much less Essential Oil, when

distilled, than Balsams do. Hence it follows, that Resins are to

Balsams, what Balsams are to Essential Oils. All these effects are

produced by the causes assigned above, and confirm the analogy we have

established.

We have no other observations to make on this analysis of Turpentine,

except that when Rosin is distilled in a retort with a naked fire, the

operation must be carried on very slowly, and the fire duly governed:

for the matter is apt to swell, and to rise in substance into the

receiver, without being at all decomposed. In order to avoid this

inconvenience, it is adviseable to make use of a long-bodied retort,

such as is known by the name of the _English Retort_.

If you stop the distillation of Rosin about mid-way, or when the

Oil that comes over begins to grow thick, you may, by changing the

receiver, keep the first Oil apart: it is pretty fluid, and of a middle

nature between the æthereal Oil, obtained with the heat of boiling

water, and the last thick Oil, that doth not rise till towards the end

of the distillation. This last thick Oil is that which Mr. Homberg

fired with concentrated Oil of Vitriol.

If we examine the matter contained in the retort, when the distillation

is thus stopped short, it appears, when cold, in the form of a solid

substance, almost perfectly diaphanous, of a deep reddish-yellow

colour, and friable: It is known by the name of _Colophony_.

This analysis of boiled Turpentine, is a specimen of the analysis of

almost all other resins; so that what hath been said on this occasion

is in a manner general, and applicable to other decompositions of the

same kind. We shall now proceed to examine some other oily matters,

which exhibit peculiar phenomena, and do not come under the general

rules.

PROCESS II.

_The Analysis of Resins: instanced in Benjamin: The Flowers and Oil of

Benjamin._

Into a pretty deep earthen pot, having a border or rim round its

mouth, put the Benjamin you intend to analyze. Cover the pot with a

large conical cap of very thick white paper, and tye it on under the

rim. Set your pot in a sand-bath, and warm it gently till the Benjamin

melt. Continue the heat in this degree for an hour and half. Then untie

the paper cap and take it off, shaking it as little as possible. You

will find all the inside of the cap covered with a great quantity of

beautiful, white, shining Flowers, in the form of little needles. Brush

them off gently with a feather, put them into a bottle, and stop it

close.

As soon as you take off the first cap, cover your pot immediately with

a second like the former. In this manner go on till you perceive the

Flowers begin to grow yellowish; and then it is proper to desist.

The matter left in the pot will be blackish and friable when cold.

Pulverize it; mix it with sand; and distil it in a glass retort with

a graduated heat. There will come over a light Oil, of a fragrant

scent, but in very small quantity; a little of an acid liquor, and a

great quantity of a red thick Oil. There will be left in the retort a

charred, spongy substance.

_OBSERVATIONS._

All oily matters, that are naturally thick and in a concrete form,

resemble each other in this, that they derive these qualities from an

Acid combined with them. But they nevertheless differ greatly from one

another in many respects. The quality, the quantity, of the Acid to

which they owe their consistence, and the manner in which it is united

with them, diversify them a thousand ways.

In the preceding process we advanced, that Natural Balsams are

distinguished from Resins by their containing so much more Oil, in

proportion to their Acid, as suffices to render them almost fluid.

For this reason they yield an essential Oil: whereas Resins, on the

contrary, are solid; all their Oil being loaded and weighed down with

a great quantity of Acid, so that no Essential Oil can be drawn from

them.

We observed at the same time, that, when all the Essential Oil

contained in a Natural Balsam is drawn off, with the heat of boiling

water, the residue takes a solid consistence, and resembles a Resin. In

fact, almost all Resins yield, by distillation, the same principles as

that residue; that is, an Oil of a middling nature between Essential

Oils and thick Oils, in point of lightness and fluidity; the whole

being always accompanied with an Acid diffused in phlegm.

In consequence hereof, the analysis of Benjamin, described in the

process, appears to vary much from that of other Resins: for here we

see a volatile matter in a concrete form; namely, the white Flowers

that rise first; which doth not usually occur in the analysis of

Resins. Yet, if we examine the matter, we shall be convinced that

it is very analagous to one of the principles obtainable from all

Resins; that indeed it differs therefrom in some of its properties,

particularly in its external form; but that it is in reality the very

same.

In fact, the Flowers of Benjamin are no other than an Oily Acid,

nearly of the same nature with those obtained from all other vegetable

substances; but which, instead of being liquid like them, appears in a

dry concrete form, and in a manner crystallized. It probably derives

this property from its Oil being combined with its Acid, either in

greater quantity, or in a more intimate manner, than in the rest,

and so strongly united therewith as not to be separated from it by a

subliming heat; or from hence, that the compound, of which it is a

part, contains too little phlegm to dissolve it; or else, that it is

hindered from dissolving therein by the Oil with which it is combined.

Perhaps all these causes may concur together in producing its concrete

form.

The saline character of this substance appears chiefly from its being

soluble in water: but the water must be very hot, and even boiling,

before it will effect this solution; and when it cools, the Salt shoots

into fine needles at the bottom. This phenomenon directs us to a method

of separating it from Benjamin without sublimation.

For this purpose the Resin must be boiled in water: the water will

then dissolve the Salt; and, as it cools, the Salt will crystallize,

and may be easily collected. But as the Oil, with which the Acid

is combined, hinders the water from dissolving it so easily as it

otherwise would, we cannot obtain quite so much of it, from the same

quantity of Benjamin, by decoction as by sublimation; the last portions

thereof being united with a great quantity of Oil, which defends them

against the action of the water. This Salt dissolves readily in Spirit

of Wine, on account of the Oil combined with it. A course of well

connected experiments might give us a far greater insight into its

natural properties than we can now boast of.

Benjamin yields a much smaller quantity of fluid Oil by distillation

than other Resins do; because the greatest part of its Oil is employed

in the composition of its oily, volatile, acid Salt. The thick Oil

drawn from this Resin, is thicker than that obtained from any other

Resin, and even fixes like butter when cold; nor can we get more than

a very small quantity of Acid in a distinct liquor. All these effects

depend on what we mentioned above, in relation to its saline flowers:

to wit, the peculiar and intimate union between the Acid and Oily

part of this Resin, so that the fire cannot so easily or so perfectly

disjoin them, as it doth those of other Resins.

Benjamin, when distilled, leaves in the retort much more of a charred

coal than is left by most other resinous matters. This may be owing

to the considerable quantity of earthy matter which it contains, and

which, perhaps, may also be one of the causes that contribute to give

its Salt a concrete form.

REFLECTIONS

_On the Nature and Properties of_ CAMPHOR.

We do not propose to give an analysis of this singular body; because

hitherto there is no process known in Chymistry by which it can be

decomposed. We shall therefore content ourselves with reciting its

principal properties, and making a few reflections on its nature.

Camphor is an oily concrete substance; a kind of Resin, brought to

us from the island of Borneo, but chiefly from Japan. This substance

resembles Resins, in being inflammable, and burning much as they do; it

is not soluble in water, but dissolves entirely and perfectly in Spirit

of Wine; it is easily separated again from this menstruum, as all

other oily matters are, by the addition of water; it dissolves both in

expressed and in distilled Oils; it hath a very strong aromatic smell.

These are the chief properties which Camphor possesses in common with

Resins: but in other respects it differs totally from them; especially

in the following particulars.

Camphor takes fire and flames with vastly more ease than any other

Resin. It is so very volatile, that it vanishes entirely in the air,

without any other heat than that of the atmosphere. In distillation it

rises entire, without any decomposition, or even the least alteration.

It dissolves in concentrated mineral Acids; but with circumstances very

different from those that attend other oily or resinous substances. The

dissolution is accompanied with no effervescence, no sensible heat; and

consequently can produce no inflammation. Acids do not burn, blacken,

or thicken it, as they do other oily matters; on the contrary, it

becomes fluid, and runs with them into a liquor that looks like Oil.

Camphor doth not, like other oily matters, acquire a disposition to

dissolve in water by the union it contracts with Acids; though its

union with them seems to be more intimate than that of many oily

matters with the same Acids. On the contrary, if a combination of

Camphor and an Acid be diluted with water, these two substances

instantly separate from each other: the Acid unites with the water, and

the Camphor, being entirely disengaged from it, swims on the surface

of the liquor. Neither Volatile Alkalis, nor the most caustic Fixed

Alkalis, can be brought into union with it; for it always eludes their

power.

Notwithstanding these wide differences between Camphor and all other

oily and resinous substances, the rule, that Acids thicken Oils, seems

to be universal, and so constantly observed by nature, that we cannot

help thinking this substance, like all the rest, is an Oil thickened by

an Acid. But what Oil? What Acid? and how are they united? This is a

subject for very curious inquiries.

With a yellow Oil drawn from wine, and an acid vinous Spirit, of

which we shall say more under the article of Æther, Mr. Hellot made a

kind of artificial Camphor; a substance having the odour, favour, and

inflammability of Camphor; an imperfect Camphor. True Camphor hath the

levity, the volatility, and the inflammability of Æther. Can it be a

substance of the same nature with Æther, a kind of solid Æther, an

Æther in a concrete form?

PROCESS III.

_The Analysis of Bitumens: instanced in Amber, The Volatile Salt and

Oil of Amber._

Into a glass retort put some small bits of Amber, so as to fill but two

thirds of the vessel. Set your retort in a furnace covered with its

dome; fit on a large glass receiver; and, beginning with a very gentle

heat, distil with degrees of fire. Some phlegm will first come off,

which will gradually grow more acid, and be succeeded by a Volatile

Salt, figured like fine needles, that will stick to the sides of the

receiver.

Keep the fire up to this degree, in order to drive over all the Salt.

When you perceive that little or none rises, change the receiver, and

increase your fire a little. A light, clear, limpid Oil will ascend.

As the distillation advances, this Oil will grow higher coloured, less

limpid, and thicker, till at last it will be opaque, black, and have

the consistence of Turpentine.

When you perceive that nothing more comes off, though the retort be

red-hot, let the fire go out. You will have in the retort a black,

light, spongy coal. If you have taken care to shift the receiver, from

time to time, during the distillation of your Oil, you will have sundry

separate portions thereof, each of which will have a different degree

of tenuity or thickness, according as it came over at the beginning, or

towards the end of the distillation.

_OBSERVATIONS._

The substance of which we have here given the analysis, together with

all others of the same, that is, of the Bituminous kind, is by most

Chymists and Naturalists classed with Minerals: and so far they are

right, that we actually get these mixts, like other minerals, out of

the bowels of the earth, and never procure them immediately from any

vegetable or animal compound. Yet we have our reasons for proceeding

otherwise, and for thinking that we could not, in this work, place them

better, than immediately after those vegetable substances which we call

Resins.

Several motives determine us to act in this manner. The analysis of

Bitumens demonstrates, that, with regard to the principles of which

they consist, they are totally different from every other kind of

mineral; and that, on the contrary, they greatly resemble vegetable

Resins in almost every respect. In short, though they are not

immediately procured from vegetables, there is the greatest reason for

believing that they were originally of the vegetable kingdom, and that

they are no other than resinous and oily parts of trees or plants,

which, by lying long in the earth, and there contracting an union with

the mineral Acids, have acquired the qualities that distinguish them

from Resins.

Mineralogists know very well that we find, every where in the earth,

many vegetable substances, that have lain very long buried under it,

and frequently at a considerable depth. It is not uncommon to find,

under ground, vast beds of fossile trees, which seem to be the remains

of immense forests: and Bitumens, particularly Amber, are often found

among this subterraneous wood.

These considerations, joined to proofs drawn from their analysis, make

this opinion more than probable: nor are we singular in maintaining it,

as it is adopted by many able modern Chymists.

The analysis of Amber, above described, may serve as a general specimen

of the decomposition of other Bitumens: with this single difference,

that Amber is the only one among them which yields the Volatile Salt

aforesaid; and this determined us to examine it preferably to any

other. As for the rest, they all yield a phlegm, an acid liquor, and

an Oil; which is thin at first, but grows thicker and thicker, as the

distillation draws towards an end. It must be understood, however, that

these Acids and these Oils may differ, according to the nature of the

Bitumens from which they are drawn; just as the Phlegm, the Acid, and

the Oil, resulting from the decomposition of Resins, differ in quantity

and quality, according to the nature of the Resins from which they are

procured.

The principal differences observed between Resins and Bitumens are

these: the latter are less soluble in Spirit of Wine; have a peculiar

scent, which cannot be accurately described, and of which the sense of

smelling only can judge; and their Acid is stronger and more fixed.

This last property is one of the motives which induce us to think,

that, besides the vegetable Acid, originally combined with the resinous

or oily matter now become a Bitumen, a certain quantity of mineral Acid

hath, in a course of time, been superadded to constitute this mixt.

We shall presently see that the fact is certainly so, in the case of

Amber at least.

Almost all authors, who mention the analysis of Amber, have given

different accounts of the volatility of its Salt, and of the time

of the distillation when it begins to rise. Some make it ascend

immediately after the first acid phlegm. Others say, that it doth

not begin to appear till after the first thin Oil; and others again

affirm, that it comes over with the last thick Oil. Mr. Bourdelin, who

hath examined this matter to the bottom, in a Memoir on the analysis

of Amber given in to the Academy, very judiciously remarks, that the

different results which those Chymists met with in analyzing our mixt,

arose wholly from the different manner wherein each conducted his fire

during the operation.

It is certain that such a cause is capable of producing vast

differences: for when fire is hastily applied, or made too violent, it

not only confounds and tumultuously mingles the principles of the body

to be analyzed, but it even frequently drives up the entire substance

itself out of the retort into the receiver, without decomposing it at

all. This is really so in the case of Amber, and of almost all compound

substances that are not extremely fixed.

It ought therefore to be observed, as a general and important rule in

every analysis, to administer the fire exceeding slowly and cautiously,

as one can never err on that side; and to increase it only by such

degrees as appear necessary for carrying on the distillation. By

observing this method, an accurate analysis will be attained: by this

means the Salt of Amber will rise before the Oil; whereas, if a degree

of heat sufficient to raise the thin Oil, or even the thick Oil, be

applied at first, the Salt will accordingly come over with the one or

the other of these Oils.

Chymists remained a long time unacquainted with the nature of this Salt

of Amber, and authors of the greatest name agreed as little on this

point as on that just mentioned. Some asserted it to be a Volatile Salt

of the same kind with that which is obtained from animal substances;

that is, a Volatile Alkali: others, on the contrary, pretended that it

was an Acid of a singular nature.

It is very surprising that such authors should disagree on such a

point, considering how easily it may be ascertained whether this Salt

be really an Acid or an Alkali. Mr. Bourdelin justly decides the

question in favour of those who affirm it to be an Acid. In fact it

hath all the properties of an Acid: it hath the taste of one, forms

Neutral Salts with Alkalis, and differs from the most unquestionable

Acids in this alone, that, being combined with a portion of Oil and

a small quantity of earth, these give it a concrete form; which is

not a solitary case in Chymistry, as is evident from Cream of Tartar.

With regard to its Volatility, there is nothing in that repugnant to

the properties of its constituent principles; seeing the Acid and the

Oil predominant therein may easily be supposed to communicate their

volatile nature to the small portion of earth with which they are

combined.

Those Chymists who looked upon the Salt of Amber as a Volatile Alkali,

either did not examine it thoroughly, but contented themselves with its

first appearance, in which it resembles the Volatile Salt of animals,

or else were led into the error by some particular circumstances. We

know, for example, that animal as well as vegetable substances are dug

out of the earth. The insects, sometimes found inclosed in lumps of

Amber, sufficiently prove this. Perhaps they made their experiments on

such pieces of Amber; or else, that which they used might be mixed with

some animal substance not very perceptible. In such a case, it would be

no wonder if the Volatile Salt obtained should shew some tokens of an

Alkali: for the Volatile Alkali arising from the animal matter would

only be mixed, not combined, with the Salt of the Amber; as the great

quantity of the Oil, in which both these Salts are entangled, would

hinder them from dissolving each other, and forming such a Neutral Salt

as would be produced in other circumstances.

The acid or alkaline nature of the Salt of Amber was not the only

point that remained to be discussed on this occasion. Its acid quality

being once clearly ascertained, the nature of this Acid was next to

be determined. This is the object chiefly aimed at in Mr. Bourdelin's

Memoirs, and his discovery thereof is unquestionably one of the finest,

and at the same time one of the most difficult, that could be attempted

with regard to this Bitumen.

It appears plainly from several experiments, of which we have given an

account in the course of this work, that the strongest mineral Acids,

by being combined with an oily matter, are so vastly altered, and so

strangely disguised, that we not only are incapable of distinguishing

what they are, but even can hardly avoid decomposing, and partly

destroying them, by those very operations which seem the best adapted

to separate them from the Oil in which they are inviscated. Mr.

Bourdelin had all these difficulties to surmount, and incessantly met

with new obstacles in that troublesome fatty matter, which, like an

impenetrable veil, concealed from his view the Acid whose nature he

wanted to discover. But at last, by dint of manifold experiments, he

happily gained his end. Two parts of pure Nitre, unadulterated with

the lead particle of Sea-salt, and one part of Amber, pulverized and

mingled together, procured him, by deflagration, a Salt partly neutral

and partly alkaline; which being lixiviated, and set to evaporate

spontaneously, there formed at the bottom a residue of a mucilaginous,

pappy, whitish matter, amongst which he could distinguish crystals,

that were very transparent, regularly figured, of a cubical form, but

rather oblong; so that they represented little oblong squares most

exactly formed, and about half a line thick.

As these crystals perfectly resembled, in their figure, the Neutral

Salt produced by a combination of the Acid of Sea-salt with the

alkaline basis of Nitre; this was a proof to Mr. Bourdelin that

the Acid of Amber is of the same kind, or rather exactly the same,

with that of Sea-salt. The Nitre being alkalizated by means of the

phlogiston of the Amber, the Acid of the Bitumen, finding this Alkali a

proper basis to fix in, unites with it, and by that means is enabled to

resist the action of the fire, so as not to be carried off by it.

On the other hand, it is separated from the fat matter by which it

was masked before; for by the help of this fat matter the Nitre

is alkalizated. The Acid, having by this means recovered all its

properties, begins to discover them, as hath been said, by the figure

it constantly gives to the crystals of the Neutral Salt which it helps

to constitute.

Moreover, this Neutral Salt hath all the essential properties of

Sea-salt. It hath its taste; it decrepitates in the same manner on

live coals; if Oil of Vitriol be poured on it, white vapours arise,

which have the smell of Spirit of Salt, and are an actual Spirit of

Salt. Lastly, it makes a white precipitate of Mercury dissolved in

Spirit of Nitre, and a _luna cornea_ of Silver dissolved in the same

Spirit; which last proofs would alone be sufficient to establish Mr.

Bourdelin's opinion, though we had no other.

It were to be wished that the experiments which Mr. Bourdelin hath

made on Amber were also tried on other Bitumens. There is reason to

think they would be found to contain either the Marine or the Vitriolic

Acid: for though they do not yield a Volatile Salt, as Amber doth,

in distillation, yet the Acids obtained from them are very strong,

and appear, as we said before, to have a mineral origin. Mr. Geoffroy

observed, that Amber, being pulverized and infused in hot water, parts

with its Salt in the same manner as Benjamin does; which gives room to

suspect that Amber is to Bitumens what Benjamin is to Resins.

PROCESS IV.

_The Analysis of Bees-Wax, and such Oily Compounds as are analogous to

it._

Melt the Wax you intend to analyze, and mix with it as much fine sand

as will make it into stiff paste. Put this paste in little bits into a

retort, and distil as usual, with a graduated fire, beginning with a

very gentle heat. An acid phlegm will come over, and be followed by a

liquor which at first will look like an Oil, but will soon congeal in

the receiver, and have the appearance of a butter or grease. Continue

the distillation, increasing the fire by insensible degrees, till

nothing more will come off. Then separate the butter from the acid

phlegm in the receiver, mix it with fresh sand, and distil it again

just as you did the Wax before. Some acid phlegm will still come off,

and an Oil will ascend, which will not fix in the receiver, though it

be still thick. Continue the distillation, with a fire so governed

that the drops may succeed each other at the distance of six or seven

seconds of time. Do not increase it, till you perceive the drops fall

more slowly; and then increase it no more than is necessary to make

the drops follow each other as above directed. When the distillation

is finished, you will find in the receiver the Oil come wholly over,

and a little acid phlegm. Separate the Oil from this liquor; and, if

you desire to have it more fluid, re-distil it a third time in the same

manner.

_OBSERVATIONS._

Bees-Wax, like all other oily matters in a concrete form, is an Oil

thickened by an Acid. Its decomposition furnishes us with a very

convincing proof of this truth; which, you see, is confirmed more and

more, by every new analysis we make of such substances.

Wax doth not part with all its Acid in the first distillation: and this

is the reason that it doth not then become a fluid Oil, but a butter,

which hath only a degree of softness proportioned to the quantity of

Acid separated from it. The same thing holds with regard to its butter;

which losing, by a second distillation, a great part of the remaining

Acid which caused its consistence, is by that means turned to an Oil.

Lastly, this Oil, from being thick, becomes very fluid by a third

distillation, and so follows the general rule of Oils; which always

become the more fluid the oftener they are distilled or rectified.

What is here said concerning Wax is applicable to Resins, also; which

it further resembles in its consistence, and its refusing to dissolve

in water: yet it differs from them essentially in several respects; and

for this reason we thought proper to treat of it in particular. The

properties in which it differs from Resins are these:

First, It hath no aromatic scent, nor acrid taste, as Resins have.

Secondly, It doth not yield a thin limpid Oil, in the first

distillation, as they do.

Thirdly, Its Oil, or its butter, doth not grow sensibly thicker with

age. Mr. Boerhaave kept some butter of Bees-Wax for twenty years, in a

vessel that was not stopt, but only covered with a bit of paper; yet it

did not grow hard. An Essential Oil, though kept much closer shut up,

would in much less time have acquired the consistence of a Balsam; and

a Balsam, in that time, would have become a Resin.

Fourthly, Bees-Wax is not soluble in Spirit of Wine; whereas it is the

very nature of Resins to dissolve in that menstruum.

Fifthly, I have observed that Spirit of Wine acts faintly on the butter

of Bees-Wax; dissolves that butter when distilled to an Oil; unites

more readily with that Oil when rectified by a third distillation;

and dissolves it still the more readily the oftener it is distilled.

Resins, on the contrary, are more soluble in Spirit of Wine than the

thin Oils drawn from them; and those Oils acquire the property of

resisting that menstruum more and more obstinately the oftener they are

rectified.

By these differences we may judge whether it be proper to confound

Bees-Wax with Resins, or whether it ought not rather to be considered

as an oily compound of a singular species, which deserves to be ranked

in a different class, or at least in some other division.

If we take the most cursory view of the properties of Essential Oils,

and compare them with those of Fat Oils, we cannot avoid being struck

with a resemblance between the properties of Essential Oils and

those of Resins, as well as with the apparent conformity between the

properties of Fat Oils and those of Bees-Wax: from all which we may

conclude with good reason, in my opinion, that the Oil of Bees-Wax

is not of the same nature with that of Resins. The Oil of Resins hath

all the properties of an Essential Oil, and is justly allowed to be

an Essential Oil rendered thick and ponderous by an Acid. The Oil of

Bees-Wax, on the contrary, hath all the properties of Fat Oils; and

there is great room to think, that this substance is really no other

than a Fat Oil hardened by an Acid.

Bees-Wax is not the only oily compound that appears to have a Fat

Oil for its basis. Certain shrubs in America yield, by decoction, a

substance that hath all the properties of Bees-Wax, differing therefrom

only in its colour, which is green. The Butter of Cacao is also a

substance analogous to Bees-Wax, and would be really Wax, if it were

but as hard; for it contains the same principles, but in different

proportions: in short, it is to Bees-Wax what Balsams are to Resins.

PROCESS V.

_The Saccharine Juices of Plants analyzed: instanced in Honey._

Put into a stone cucurbit the Honey you intend to distil; set it in a

moderate sand-heat, and evaporate the greatest part of its humidity,

till you perceive the phlegm begin to be acid. Then take out the matter

remaining in the cucurbit, put it into a retort, leaving a full third

thereof empty, and distil in a reverberatory with degrees of fire. An

acid, amber-coloured liquor will come over. As the operation advances,

this liquor will continually become deeper coloured and more acid, and

at the same time a little black Oil will ascend. When the distillation

is over, you will find in the retort a pretty large charred mass, which

being burnt in the open air, and lixiviated, affords a Fixed Alkali.

_OBSERVATIONS._

If we consider nothing but the nature of the principles obtained from

Honey, we may be induced to think that this substance is of the same

kind with Resins; for we get from each a Phlegm, an Acid, an Oil, and

a Coal. Yet there is a very great difference between these two sorts

of compounds. Oily matters of the resinous kind are very inflammable,

and by no means soluble in water: Honey, on the contrary, is not

inflammable in its natural state; will not flame till it be half

consumed, or turned almost to a coal, by the fire; and mixes readily

and perfectly with water. Now whence can this difference arise? Since

it is not owing to the nature of the principles that constitute these

mixts, it must necessarily be attributed to the proportions in which

those principles are united. And indeed if we attend to the quantities

obtained from each by analyzing them severally, we shall find that,

in this respect, there is a very great difference between them. Oily

compounds of the nature of Resins, which are not soluble in water,

yield in distillation a little phlegm, a quantity of Oil vastly

exceeding that of their Acid, and a very small matter of coal, which,

when burnt, scarce leaves any token of a Fixed Alkali. Honey, on the

contrary, and all other juices of the same nature, give out, when

analyzed, a great deal of phlegm, a quantity of Acid much superior to

that of their Oil, and a considerable mass of coal; from which, when

burnt in the open air and lixiviated, a very perceptible Alkali may be

obtained.

If the quantity of the principles procured by these two analyses be

compared together, it will be easy to deduce from thence the causes

of the different properties observed in the mixts that afforded them.

In the large quantity of Oil, of which resinous substances consist

almost entirely, we see the cause of their being so inflammable, and so

indissoluble in water. When such bodies are decomposed, there remains

but little coal, and very little Fixed Alkali; because their Oil

carries off with it almost all their Acid, leaving a scarce perceptible

portion thereof fixed in the coal. Now we know that this Acid is an

essential requisite to the formation of an Alkali. Honey, on the

contrary, and the analogous mixts, are so unapt to take fire, and mix

so readily with water, only because there is very little Oil in their

composition, in comparison of the Acid, which is their predominant

principle. For the same reason they leave, when decomposed, a greater

quantity of coal, which also yields much more Fixed Alkali than we find

in the coals of Resins. Perhaps these mixts may also contain a little

more earth. The cause of this greater quantity of Fixed Alkali will

be found in what we delivered above concerning the combination and

production of that Salt.

Sugar, Manna, and the Saccharine juices of fruits and plants, are of

the same nature as Honey, yield the same principles, and in the same

proportions. All these substances must be considered as native Soaps;

because they consist of an Oil rendered miscible with water, by means

of a saline substance. They differ from the common artificial Soaps in

several respects; but chiefly in this, that their saline part is an

Acid, whereas that of common Soap is an Alkali. The natural Soaps are

not for that reason the less perfect: on the contrary, they dissolve

in water without destroying its transparency, and without giving it a

milky colour: which proves that Acids are not less proper than Alkalis,

or rather that they are more proper additaments, for bringing Oils into

a saponaceous state.

But it must be owned, that we are not yet able to imitate by art the

Acid Soaps which are prepared and so perfectly combined by nature, and

that the detersive quality of these is not near so strong as that of

the Soaps which have an Alkali for their saline principles.

Though Honey, and the other vegetable substances analogous to it,

contain much Acid, yet they have no taste of sourness, nor any of the

other properties of Acids; but, on the contrary, their taste is soft

and saccharine: the cause of this is, that their Acid is intimately

mixed and perfectly combined with their Oil, which entirely sheathes

and blunts it.

PROCESS VI.

_Gummy Substances analyzed: instanced in Gum Arabic._

Distil Gum Arabic in a retort with degrees of fire. A limpid,

scentless, and tasteless phlegm will first come over; and then a

russet-coloured acid liquor, a little Volatile Alkali, and an Oil,

which will first be thin and afterwards come thick. In the retort will

be left a good deal of a charred substance, which being burnt and

lixiviated will give a Fixed Alkali.

_OBSERVATIONS._

Gums have at first sight some resemblance of Resins; which hath

occasioned many resinous matters to be called Gums, though very

improperly: for they are two distinct sorts of substances, of natures

absolutely different from each other. It hath been shewn, that Resins

have an aromatic odour; that they are indissoluble in water, and

soluble in Spirit of Wine; that they are only an Essential Oil grown

thick. Gums, on the contrary, have no odour, are soluble in water,

indissoluble in Spirit of Wine, and, by being analyzed as in the

process, are converted almost wholly into a phlegm and an Acid. The

small portion of Oil contained in them is so thoroughly united with

their Acid, that it dissolves perfectly in water, and the solution is

clear and limpid. In this respect Gums resemble Honey, and the other

vegetable juices analogous to it. They are all fluid originally; that

is, when they begin to ooze out of their trees. At that time they

perfectly resemble mucilages, or rather they are actual mucilages,

which grow thick and hard in time by the evaporation of a great part of

their moisture: just as Resins are true Oils, which, losing their most

fluid parts by evaporation, at last become solid. Infusions or slight

decoctions of mucilaginous plants, when evaporated to dryness, become

actual Gums.

Some trees abound both in Oil and in mucilage: these two substances

often mix and flow from the tree blended together. Thus they both grow

dry and hard together in one mass, which of course is at the same

time both gummy and resinous: and accordingly such mixts are named

Gum-resins.

But it must be observed, that these resinous and gummy parts suffer

no alteration by being thus mixed; but each preserves its properties,

as if it were alone. The reason is, that they are not truly united

together: Gums being indissoluble by Oils or by Resins, the parts of

each are only entangled among those of the other, by means of their

viscosity. Hence, if the Gum-resin be put into water, the water will

dissolve only the gummy part, without touching the resinous. On the

contrary, if the same Gum-resin be put into Spirit of Wine, this

menstruum will dissolve the Resin, and leave the Gum. We shall treat

more particularly of this dissolution under the head of Spirit of Wine.

If a Gum-resin, instead of being only infused in water, be triturated

with water, it will be thereby wholly diffused through it: but the

resinous part, which is only divided by the triture, and not dissolved

in the water, gives the liquor a milky colour, like that of an

emulsion. It is indeed an actual emulsion; that which is made with

kernels being, like this, no other than a divided oil, dispersed in

small particles by triture, and suspended in the water by means of a

mucilage.

SECTION II.

_Of Operations on Fermented Vegetable Substances._

CHAP. I.

_Of the_ PRODUCT _of_ SPIRITUOUS FERMENTATION.

PROCESS I.

_To make Wine of Vegetable Substances that are susceptible of

Spirituous Fermentation._

Let a liquor susceptible of, and prepared for, the Spirituous

Fermentation be put into a cask. Set this cask in a temperately warm

cellar, and cover the bung-hole with a bit of linen cloth only. In more

or less time, according to the nature of the liquor to be fermented,

and to the degree of heat in the air, the liquor will begin to swell,

and be rarefied. There will arise an intestine motion, attended with a

small hissing and effervescence, throwing up bubbles to the surface,

and discharging vapours: while the gross, viscous, and thick parts,

being driven up by the fermenting motion, and rendered lighter by

little bubbles of air adhering to them, will rise to the top, and there

form a kind of soft, spongy crust, which will cover the liquor all

over. The fermenting motion still continuing, this crust will, from

time to time, be lifted up and cracked by vapours making their escape

through it; but those fissures will presently close again, till, the

fermentation gradually going off, and at last entirely ceasing, the

crust will fall in pieces to the bottom of the liquor, which will

insensibly grow clear. Then stop the cask close with its bung, and set

it in a cooler place.

_OBSERVATIONS._

Matters that are susceptible of the Spirituous Fermentation are seldom

so perfectly prepared for it by nature as they require to be. If we

except the juices that flow naturally from certain trees, but oftener

from incisions made on purpose in them, all other substances require

some previous preparation.

Boerhaave, who hath handled this subject excellently well in his

Chymistry, divides the substances that are fit for Spirituous

Fermentation into five classes. In the first he places all the mealy

seeds, the legumens, and the kernels of almost all fruits. The

second class includes the juices of all fruits that do not tend to

putrefaction. In the third class stand the juices of all the parts

of plants which tend rather to acidity than to putrefaction; and

consequently those which yield much Volatile Alkali are to be excluded.

The fourth class comprehends the juices or saps that spontaneously

distil from several trees and plants, or flow from them when wounded.

He forms his fifth and last class of the saponaceous, saccharine,

and concrete or thick juices of vegetables. Resinous or purely gummy

matters are excluded, as not being fermentable.

These five classes may be reduced to two; one comprehending all the

Juices, and another all the Mealy parts, of vegetables that are

susceptible of fermentation. The juices want nothing to fit them for

fermentation, but to be expressed out of the substances containing

them, and to be diluted with a sufficient quantity of water. If they

be very thick, the best way is to add so much water as shall render

the mixed liquor just capable of bearing a new-laid egg. With respect

to farinaceous substances, as they are almost all either oily or

mucilaginous, they require a little more management. The method of

brewing malt-liquors will furnish us with examples of such management.

It is thus described by Mr. Boerhaave.

In warm weather the grain is put into large vats, and a considerable

quantity of rain-water, or very clean river-water, is poured thereon,

in which it lies till it be well soaked and swelled. This first

operation is called the _Steeping_.

When the grain is by this means grown very plump, it is taken out of

the steep, and laid on great heaps in an open place, yet not too much

exposed to the wind. In a very little time those heaps grow hot, the

grain begins to sprout, and shoot out little buds of leaves and roots.

The art of managing this operation properly consists in seizing the

exact point of time when the germination should be stopt: on this in a

great measure depends the success of the business. For, if the grain

be left too long in this hot bed, it may begin to rot, or else the

leaves and roots, by growing too much, may consume most of the mealy

substance, which, in this case, is the only subject of fermentation;

and, if the germination be checked too soon, the advantage expected

from it will be lost; that is, the mucid matters will not be

sufficiently attenuated.

As soon therefore as the germination is observed to have attained its

proper stage, it must be stopt with all possible expedition. For this

purpose the grain is carried into an open place exposed to the north

wind, where it is spread on a boarded floor and dried; by which means

it is hindered from sprouting any more. It is next made to run slowly

down through a long tunnel made very hot, which at once dries it

thoroughly to the very heart, and in some measure scorches it, though

very slightly. Grain thus prepared is called _Malt_.

By this germination, exsiccation, and slight torrefaction of the grain,

the farinaceous substance is considerably attenuated, and its natural

viscosity destroyed, which would otherwise hinder the meal, when boiled

in water, from mixing with it and dissolving in it, as it must in some

measure do to form a liquor fit for Spirituous Fermentation.

Mr. Boerhaave takes notice, that if grain, which hath not been thus

prepared, be chewed in the mouth, its meal makes a paste that is not

easily attenuated, or entirely dissolved, by the spittle; whereas the

meal of the same grain, after malting, mixes immediately and perfectly

with the spittle: it hath moreover a sweet agreeable taste, which

common grain hath not.

The grain being thus malted, is ground: then hot water is poured

thereon, in which it is left to infuse for three or four hours. In that

time the water takes up all the attenuated flour of the Malt; whereas

it would not dissolve the farina of grain that had not undergone the

above described preparations. The Wort is then drawn off the grains,

and boiled to a proper degree of inspissation; the decoction is

suffered to cool, and afterwards put into casks to be fermented as the

process directs.

As Malt-liquor is apt to grow sour, and will not keep so long as Wine,

some bitter plants are usually boiled in the decoction, to make it keep

the longer, and hinder it from turning sour so soon as it otherwise

would. For this purpose such plants are chosen as have an agreeable

bitter taste; and the preference is generally given to Hops.

Besides these preparations, relating chiefly to Malt-liquors,

there are many other things to be observed relating to Spirituous

Fermentation in general, and to all matters susceptible of that

fermentation. For example; all grains and fruits designed for that

fermentation must be perfectly ripe; for otherways they will not

ferment without difficulty, and will produce little or no inflammable

Spirit. Such matters as are too austere, too acrid, or astringent, are

for the same reason unfit for Spirituous Fermentation; as well as those

which abound too much in Oil.

In order to make the fermentation succeed perfectly, so as to produce

the best Wine that the fermented liquor is capable of affording, it is

necessary to let it stand quiet without stirring it, lest the crust

that forms on its surface should be broken to little fragments, and

mix with the liquor. This crust is a kind of cover, which hinders the

spirituous parts from exhaling as fast as they are formed. The free

access of the air is another condition necessary to fermentation: and

for this reason the vessel that contains the fermenting liquor must

not be close stopped; the bung-hole is only to be covered with a linen

cloth, to hinder dirt and insects from falling into it. Nor must the

bung-hole be too large, lest too much of the spirituous parts should

escape and be lost.

Lastly, a just degree of warmth is one of the conditions most necessary

for fermentation: for in very cold weather there is no fermentation at

all; and too much heat precipitates it in such a manner, that the whole

liquor becomes turbid, and many fermenting and fermented particles are

dissipated.

If, notwithstanding the exactest observance of every particular

requisite to excite a successful fermentation, the liquor cannot,

without difficulty, be brought to effervesce, which scarce ever

happens but to Malt-liquor, it may be accelerated by mixing therewith

some matter that is very susceptible of fermentation, or actually

fermenting. Such matters are called _Ferments_. The crust, or _Yest_,

that forms on the surface, of fermenting liquors is a most efficacious

ferment, and on that account very much used.

It sometimes happens, that there is occasion to check the fermentation

excited in the liquor, before it ceases of itself. To effect this, such

means must be used as are directly opposite to those mentioned above

for promoting fermentation. The end is obtained by mixing with the

liquor a quantity of Alkali, sufficient to absorb the Acid contained

therein: but this method is seldom made use of, because it spoils

the liquor: which, after being thus treated, is incapable of any

spirituous fermentation, but on the contrary will certainly putrefy.

Spirituous fermentation may also be stopped by mixing with the liquor

a great quantity of some mineral Acid. But this likewise alters its

nature; because these Acids, being fixed, always remain confounded

therewith, and never separate from it.

The best method yet found out for checking this fermentation, without

injury to the fermenting liquor, is to impregnate it with the fumes

of burning sulphur. These fumes are known to be acid, and it is that

quality in them which suspends the fermentation. But, at the same time,

this Acid is extremely volatile: so that it separates spontaneously

from the liquor, after some time, and leaves it in a condition to

continue its fermentation.

For this reason, when a Wine is desired that shall be but half

fermented, and shall partly retain the sweet taste it had in the state

of _Must_, (the proper name for the unfermented juice of the grape),

it is put into casks in which Sulphur hath been previously burnt, and

the vapours thereof confined by stopping the bung-hole. These are

called _Matched Wines_. If the same operation be performed on Must,

its fermentation will be absolutely prevented: it will retain all its

saccharine taste, and is then called _Stum_. As the sulphureous Acid

evaporates spontaneously, in no long space, it is necessary to fumigate

matched wines, or stums, from time to time, when they are intended to

be kept long without fermenting.

PROCESS II.

_To draw an Ardent Spirit from Substances that have undergone the

Spirituous Fermentation. The Analysis of Wine._

Fill a large copper cucurbit half full of Wine. Fit on its head and

refrigeratory. Lute on a receiver with wet bladder, and distil with

a gentle fire; yet so that the drops which fall from the nose of the

alembic may succeed one another pretty quick, and form a sort of small

continued stream. Go on thus till you perceive that the liquor which

comes over ceases to be inflammable; and then desist. You will find in

the receiver a clear liquor, somewhat inclining to an amber-colour, of

a pleasant quick smell, and which being thrown into the fire instantly

flames. The quantity thereof will be nearly a fourth part of the Wine

you put into the alembic; and this is what is called _Brandy_; that

is, the Ardent Spirit of Wine loaded with much phlegm.

In order to rectify it, and reduce it to Spirit of Wine, put it into

a long-necked matrass, capable of holding double the quantity. Fit a

head to the matrass, and lute on a receiver: place your matrass over

a pot half full of water; set this pot over a moderate fire; and with

this vapour-bath distil your Spirit, which will rise pure. Continue

this degree of heat till nothing more will come over. You will find in,

the receiver a very clear colourless Spirit of Wine, of a quick but

agreeable smell, which will catch fire at once by the bare contact of

any flaming substance.

_OBSERVATIONS._

It hath been shewn, that Honey, and the vegetable juices analogous to

it, such as Must, and the juices of all saccharine fruits and plants,

yield by distillation no other principles than Phlegm, an Acid, and

a small quantity of Oil. The analysis of Wine, and of all substances

that have undergone the spirituous fermentation, shews us that this

fermentation produces, and in some sense creates, in those mixts, a

principle that did not exist in them before; I mean the Ardent Spirit,

which is an inflammable liquor that is miscible with water. This liquor

results from a closer combination of the Acid and the Oil, which are

attenuated and united together by fermentation. To this Oil, which

is one of its constituent parts, its inflammability is owing; and

the Acid imparts to this Oil the property of mixing with water, more

perfectly and more intimately than when it makes a part of any other

compound. Nay, there is, in the very composition of an Ardent Spirit,

a certain quantity of water which is necessary to it, which is one of

its essential parts, and without which it would not have the properties

that characterise it. We shall presently have occasion to see, that,

when Spirit of Wine is dephlegmated to a certain pitch, we cannot

deprive it of any more of its aqueous parts, without decomposing a

quantity of the Spirit, proportioned to the quantity of water drawn

from it.

Ardent Spirits are more volatile than any of the principles of the

mixt from which they are produced, and consequently more volatile

than the phlegm, the Acid, or the Oil thereof, though they wholly

consist of these. This cannot be attributed to any thing but a peculiar

disposition of these principles, which are attenuated in a singular

manner by the fermenting motion, and thereby rendered more susceptible

of expansion and rarefaction.

The great volatility of the Ardent Spirit procures us an easy method of

separating it from the other principles of Wine, and of dephlegmating

it. For this purpose it need only be distilled with such a gentle heat

as is just capable of raising the Spirit, but too weak to produce the

same effect on the other matters from which you desire to free it. For

this reason the more slowly, and with the less heat, you distil your

Wine, the stronger and more spirituous will your Brandy be. The same is

to be said of the second distillation, by which Brandy is changed into

Spirit of Wine, or, in other words, dephlegmated. The Spirit of Wine

thus drawn from it will be so much the better, the more exactly you

observe the conditions here proposed.

If Spirit of Wine be treated in the same manner as Brandy, that is,

if it be rectified by distillation with the same precautions, it

will be thereby dephlegmated as much as possible; and then it is

called _Alkohol_. By this rectification it is not only freed from

its redundant phlegm, but also from some particles of Acid and of

Oil, which, though much less volatile than itself, yet ascend with it

in the first distillation: nor is it possible wholly to avoid this

inconvenience.

Mr. Boerhaave proposes to dephlegmate Spirit of Wine more easily, and

more accurately, by distilling it from decrepitated Sea-salt mixed,

while very hot, with the Spirit. This must certainly be a very good

method; because decrepitated Sea-salt powerfully attracts moisture,

and consequently is very apt to imbibe and retain that which is in

the Ardent Spirit: and Spirit of Wine doth not dissolve Sea-salt; so

that there is no reason to fear its being in the least contaminated

therewith.

All fermented liquors do not yield near an equal quantity of Ardent

Spirit; because they do not all, before fermentation, equally contain

the principles necessary to produce an Ardent Spirit, in the most

advantageous proportion or disposition.

There are several ways of proving whether or no Spirit of Wine be as

highly rectified as it possibly can be, that is, whether or no it

contain any more phlegm than is precisely necessary to constitute it

Spirit of Wine; and many Chymists have judged that worthy of the title

which burns away entirely, without leaving behind it the least token of

humidity; or that which, being burnt on gun-powder, fires it at last.

But Mr. Boerhaave justly observes, that neither of these is a

sufficient proof; because, though there should be a small quantity

of unnecessary phlegm in Spirit of Wine, yet it may very well be

evaporated and dissipated by the deflagration in either way. He

therefore proposes another proof, which is much more to be depended on;

that is, by mixing and shaking with the Spirit of Wine a small quantity

of a very dry pulverized Alkali. If this Salt, when thus agitated, and

even warmed, with Spirit of Wine, continue as dry as it was at first,

it is a sign that the Spirit is perfectly dephlegmated.

Mr. Boerhaave tried in this manner some Spirit of Wine that had fired

gun-powder, and found it to contain so much phlegm that it moistened

his Salt very perceptibly: nay, one single drop of water, being mixed

with a considerable quantity of Spirit of Wine, which before left the

Alkali perfectly dry, discovered itself in this way by the moisture it

communicated to the very same Salt.

Spirit of Wine may also be contaminated with some heterogeneous

substances; such as acid, alkaline, or oily matters. These are to be

discovered by very easy experiments proper to each: for an acid or

alkalious Spirit of Wine being mixed with syrop of violets will give it

a red or a green colour, according to the nature of the saline matter

contained in it; and, if it be combined with an Oil, that will shew

itself by the white milky colour which a drop of it will give to water.

Besides the Ardent Spirit, Wine contains an Acid united with a portion

of earth and of Oil, which give the Acid a concrete form. This

substance generally separates spontaneously from the Wine, and adheres,

in the form of a strong crust, to the sides of the cask. It is called

_Tartar_, and is, properly speaking, the Essential Salt of Wine. We

shall exhibit the analysis of Tartar, and treat of it more at length,

in a chapter apart.

Wine-lees consist of the grossest parts of the fermented liquor; which

being uncapable of remaining dissolved, sink to the bottom, and form a

sediment, which contains also some Tartar and a little Ardent Spirit.

The residue left in the cucurbit, after the Spirit is drawn off, is a

sort of Extract of Wine. This liquor hath an exceeding rough, or rather

acid taste. When distilled it yields an acid phlegm, which comes more

and more acid as the distillation advances, and a fetid empyreumatic

Oil. From the _caput mortuum_, when burnt, a considerable quantity of a

Fixed Alkali may be extracted.

From all this it follows, that Wine consists of an Ardent Spirit, and

a Tartarous Acid, diffused through a great quantity of water, together

with some oily and earthy parts.

Malt-liquor contains much less Tartar than Wine; but, instead thereof,

it is impregnated with a mucilaginous matter, which becomes very

perceptible when any body is smeared with it and dried; for then

it makes a kind of Varnish. This mucilaginous matter, which is not

sufficiently attenuated, especially when the Malt-liquor is new, makes

it very apt to swell up and rise over the helm with rapidity, in the

distillation of an Ardent Spirit from it: for which reason it is

necessary to proceed more cautiously, and more slowly, in distilling a

Spirit from this liquor than from Wine.

PROCESS III.

_To dephlegmate Spirit of Wine by the means of Fixed Alkalis. Spirit of

Wine analyzed._

Into a glass cucurbit pour the Spirit of Wine you intend to

dephlegmate, and add to it about a third part of its weight of Fixed

Alkali, newly calcined, perfectly dry, heated, and pulverized. Shake

the vessel, that the two matters may be mixed and blended together.

The Salt will gradually grow moist, and, if the Spirit of Wine be very

aqueous, melt into a liquor, that will always lie at the bottom of the

vessel, without uniting with the Spirit of Wine which will swim at top.

When you perceive that the Alkali attracts no new moisture, and that no

more of it melts, decant your Spirit of Wine from the liquor beneath

it, and add to your Spirit fresh Salt thoroughly dried as before. This

Salt will also imbibe a little moisture; but it will not grow liquid,

because the Alkali, with which it was mixed before, hath left too

little phlegm to melt this. Decant it from this Salt as at first, and

continue to mix and make it in the same manner with fresh Salt, till

you observe that the Salt remains as dry after as it was before mixing

it with the Spirit of Wine. Then distil your Spirit in a small alembic

with a gentle heat, and you will have it as much dephlegmated as it can

be.

_OBSERVATIONS._

Next to the Mineral Acids, Fixed Alkalis perfectly calcined are the

substances which have the greatest affinity with water, and therefore

it is no wonder they are so very fit to dephlegmate Spirit of Wine,

and to free it from all its redundant humidity. Indeed Spirit of Wine

cannot be perfectly dephlegmated without their assistance: for when

distillation alone is made use of for that purpose, it is impossible

to prevent some phlegm from rising with the Spirit of Wine, whatever

precautions we take to avoid it. Hence it comes to pass, that Spirit of

Wine, though ever so highly rectified by distillation, always imparts a

little moisture to an Alkali, when mixed with it in order to prove its

goodness.

But, while the Alkali attracts the super-abundant phlegm of the Spirit

of Wine, it produces in that liquor, and undergoes itself, remarkable

changes.

Spirit of wine, when so highly dephlegmated by an Alkali that, being

kept in digestion therewith, it leaves the Salt perfectly dry, hath a

red colour, an odour somewhat different from that which is peculiar

to it when perfectly pure, a taste in which that of the Fixed Alkali

may be distinguished; and it makes a slight effervescence with Acids:

which manifestly proves, that it is united with a portion of the Alkali

employed to rectify it.

Mr. Boerhaave thinks, with great probability, that this portion of the

Alkali unites with the Spirit of Wine, much in the same manner as with

Oils, _viz_. that it forms with the Spirit a kind of liquid Soap. He

observes, that this alkalizated Spirit cleans the fingers; and that

things wetted with it do not dry so speedily as those wetted with pure

Spirit of Wine. This alkalizated Spirit is also called _Tincture of

Salt of Tartar_.

In making this Alkaline Tincture, great care is to be taken that the

Spirit of Wine you use be as highly rectified as possible: for, as long

as it communicates any phlegm to the Alkali, it doth not acquire from

the Salt mixed with it either the red colour, or the other properties

which shew it to have dissolved part thereof. It is also a rule, to

throw the Alkali exceeding hot into the Spirit of Wine, which being

heated beforehand boils on the addition of the hot Salt. In order to

render the Tincture still stronger, they are left to digest together

for some time; after which, if part of the Spirit of Wine be drawn off

by distillation, the remainder will have a redder colour and a more

acrid taste.

The Spirit drawn off by distillation is clear, colourless, and doth

not give the same tokens of an alkaline quality as the Tincture; and

for that reason, as the design of the present process is only to

dephlegmate and rectify Spirit of Wine by means of a Fixed Alkali, we

have directed it to be distilled as soon as all its phlegm is absorbed

by the Salt.

However, Spirit of Wine rectified in this manner must not be considered

as absolutely pure; for a small degree of an alkaline quality is still

perceptible in it: but that doth not hinder its being employed with

success in several chymical operations, where the property chiefly

required in Spirit of Wine is that it be perfectly dephlegmated.

In order to free Spirit of Wine from the small portion of Alkali

remaining in it after distillation, Mr. Boerhaave proposes to mix with

it a few drops of the Vitriolic Acid, before the last distillation. But

there is great reason to apprehend an opposite inconvenience from this

practice: that is, instead of an alkaline character, we may give the

Spirit an acid taint. Indeed this cannot be avoided, but by mixing with

the Spirit of Wine exactly as much Acid, as suffices to saturate the

Alkali contained in it, and no more; which is a point very difficult to

hit.

Van Helmont tells us, that having distilled Spirit of Wine from Salt

of Tartar perfectly calcined, half of it came over pure water; and Mr.

Boerhaave, to whom this appeared very surprising, resolved to repeat

Van Helmont's experiment, in order to satisfy himself of the truth, and

see with his own eyes what would be the result. With this view he made

a tincture of Salt of Tartar in the manner above described, as strong

and as fully impregnated as he possibly could. He set it in digestion

with the Alkali for several months, and afterwards let it stand four

years without touching it. He then poured the whole into a cucurbit,

and drew off the Spirit of Wine from the Salt by distillation. The

Spirit of Wine, which was before very red, became clear on being

distilled, having left its colour in the Salt which remained at the

bottom of the cucurbit. This Spirit he returned upon the Salt, and

distilled as before. He observed, that, in this second distillation,

the Spirit of Wine rose with a little more difficulty, and that the

remaining Salt was of a more saturated colour, and become of a dark

red. In this manner he cohobated and distilled his Spirit twenty times,

with the same Salt. He then found that the Spirit of Wine had acquired

a caustic, fiery taste, and that the saline mass in the bottom of the

cucurbit was grown black. This saline residue he distilled with a

stronger fire, and obtained from it a liquor, which was water, and not

Spirit of Wine.

Though Mr. Boerhaave seems, by this tedious labour, to have made Van

Helmont's experiment succeed, at least in part, yet that famous and

accurate Philosopher did not flatter himself with the notion of having

solved the problem. He first observes, that he was far from getting the

quantity of water which Van Helmont says he obtained, _viz._ half the

weight of the Spirit of Wine. Secondly, he could scarce think that the

quantity he did obtain actually came from the Spirit of Wine. The thing

appeared to him so singular, and so hard to be accounted for, that he

inclined to believe the water was quite extraneous both to his Spirit

of Wine and to his Salt, and that it came from the air, which could not

but be admitted in the frequent cohobations of the Spirit of Wine with

the Alkali.

When Mr. Boerhaave undertook this long laborious course of operations,

he had it also in his view to try whether he could not, by the same

means, solve another problem famed among the Chymists, namely, the

Volatilization of the Salt of Tartar. He acquaints us, that in this

also he failed; which may easily be believed: but, in my opinion, he

was more successful with regard to the first point, than he himself

imagined; for I think the water he obtained came immediately from the

Spirit of Wine. We shall easily be convinced of this, if we carefully

consider all the circumstances attending his experiments.

It hath been shewn, that Spirit of Wine consists of an Oil, of an

Acid, and of water, with which the Oil is intimately mixed by means of

the Acid; that Spirit of Wine, which is not perfectly dephlegmated,

may be deprived of a pretty considerable quantity of Water, which is

superfluous and unnecessary to its composition; and that it suffers

no change thereby, except that it becomes lighter, stronger, more

inflammable, in short, more Spirit of Wine: but that, when it is once

freed of this super-abundant phlegm, it would be in vain to attempt

separating a greater quantity of water from it. All the water then left

in it is essential to its composition, and necessary to give it its

properties; for, without that, it would not be Spirit of Wine, but only

an Oil loaded with an Acid.

This being laid down, the water which cannot be separated from Spirit

of Wine while it continues Spirit of Wine, must become sensible when it

is decomposed. And this actually comes to pass: for if you rob Spirit

of Wine of one of its principles, its Oil, for instance, and for that

purpose burn it under a glass bell, as you do Sulphur, you will by this

means collect a great quantity of water, even though you make use of

the most highly rectified Spirit of Wine; which proves that this water

was one of the essential parts that constituted the Spirit.

If, instead of depriving this mixt of its oily principle, you separate

from it one of its other principles, such as its Acid, it is plain that

it will in like manner be decomposed, and that then the Oil and the

water, which were combined together only by means of that Acid, will

separate from one another, and appear each in its natural form. Now

this is exactly the case in Van Helmont's experiment, as repeated by

Boerhaave. The Fixed Alkali, on which the Spirit of Wine is cohobated,

hath a greater affinity with the Acid of this mixt than with its phlegm

or its Oil. It therefore unites with part of that Acid; by which means

a proportional quantity of its Oil and water must needs separate from

each other, and of course a portion of the Spirit of Wine will be

decomposed. Accordingly Boerhaave observed, that, in dephlegmating

Spirit of Wine by a Fixed Alkali, a portion of Oil is always separated

from it, and that the Alkali employed in this operation is impregnated

with an Acid, so that, when it hath been several times used for this

purpose, it is almost changed into a Neutral Salt, and hath acquired

the properties of the Foliated Salt of Tartar. That on which Spirit of

Wine hath been cohobated a great number of times must consequently be

impregnated with a great quantity of Acid; and, as the Acid carries

with it a great deal of water, it is not surprising that when the

Alkali, thus impregnated with Acid and phlegm, is exposed to a strong

fire, the phlegm should be separated from it: seeing the union between

them is but weak.

Thus it appears that the water obtained by Mr. Boerhaave, in his

experiment, came immediately from the Spirit of Wine, agreeably to

Van Helmont's notion; whose most intelligent followers have clearly

explained his sentiments on this subject, telling us, as their author's

positive assertion, that, "in his experiment, the purest Spirit of Wine

deposites one of its principles in the Salt of Tartar; that another

of them is turned into water, and so separated from that Spirit, and

from the principle attracted by the Salt of Tartar; that consequently

Spirit of Wine certainly consists of these two principles, which may be

separated from each other; and that the principle which unites with the

Alkali of the Tartar changes this Salt into a medicament, or Balsam, of

admirable virtue in curing wounds, known by the title of the _Samech_

of _Paracelsus_."

It may here be asked, why Boerhaave obtained but a small quantity of

water in this experiment, seeing Van Helmont pretends that it ought to

be equal to half the weight of the Spirit of Wine. The most natural

answer to this question is, that, as Van Helmont did not publish all

the circumstances of his experiment, there is reason to think Boerhaave

did not go about it in the same manner as Van Helmont did.

In my opinion he would have succeeded perfectly, and have obtained from

his Spirit of Wine the whole quantity of water he desired, if, instead

of cohobating it always on the same Alkali, he had taken fresh Alkali

every time; had drawn a tincture from it; had distilled his Spirit of

Wine from this Salt; and, after collecting all the parcels of Alkali

remaining after those distillations, he had exposed them to a strong

fire, in order to separate all the moisture contained in them. Perhaps

also such a great number of cohobations and distillations would not

have been necessary to decompose the Spirit of Wine totally by this

method; especially if he had employed a greater quantity of Alkali

in each operation. For it is evident, that a Fixed Alkali, by being

impregnated with a certain quantity of the Acid and water of the Spirit

of Wine, loses thereby a great deal of its strength and activity, and

at last becomes incapable of absorbing any more; so that, when it is

entirely saturated, it is no more able to act upon Spirit of Wine, so

as to decompose it, than so much Vitriolated Tartar, or common Sand.

Hence you see, that there are still many beautiful experiments to be

made on this subject, and that we may hope by a regular course of them

to obtain a perfect solution of Van Helmont's problem.

In the following processes we shall treat of another method of

decomposing Spirit of Wine, which consists in depriving it of its

essential water, or aqueous principle, by the means of highly

concentrated Acids.

CHAP. II.

SPIRIT OF WINE _combined with_ DIFFERENT SUBSTANCES.

PROCESS I.

_To combine Spirit of Wine with the Vitriolic Acid. This combination

decompounded. Rabel's Water. Æther. Sweet Oil of Vitriol. Hoffman's

Anodyne Mineral Liquor._

Into an English glass retort put two pounds of Spirit of Wine perfectly

dephlegmated, and pour on it at once two pounds of highly concentrated

Oil of Vitriol: shake the retort gently several times, in order to mix

the two liquors. This will produce an ebullition, and considerable

heat; vapours will ascend, with a pretty loud hissing noise, which will

diffuse a very aromatic smell, and the mixture will be of a deeper or

lighter red colour, according as the Spirit of Wine was more or less

oily. Set the retort on a sand-bath, made nearly as hot as the liquor;

lute on a tubulated ballon, and distil the mixture with a fire strong

enough to keep the liquor always boiling: a very aromatic Spirit of

Wine will first come over into the ballon, after which the Æther will

rise. When about five or six ounces of it are come off, you will see

in the upper concavity of the retort a vast number of little points in

a veined form, which will appear fixed, and which are nevertheless so

many little drops of Æther, rolling over one another, and trickling

down into the receiver. These little points continue to appear and

succeed each other to the end of the operation. Keep up the same

degree of fire, till upon opening the little hole in the ballon you

perceive that the vapours, which instantly fill the receiver, have the

suffocating smell of volatile Spirit of Sulphur[12].

[12] These white vapours do not appear when the vessels are perfectly

close. Mr. Hellot, to whom we owe the remark, having performed this

operation in a crystal retort procured from London, the neck of which

had been rubbed with emery in the mouth of its receiver, so that

these two vessels fitted each other exactly, saw the ætherial liquor

distil pretty fast, but without white vapours. He then loosened the

receiver, by turning it a little upon the neck of the retort, so that

the external air might get in; whereupon the white vapours appeared

immediately. When the receiver was close fitted on again, the vapours

disappeared. He repeated the same thing five times from half hour to

half hour, and these vapours as often appeared and disappeared.

Then unlute the ballon, pour the liquor it contains into a crystal

bottle, and stop it close: there will be about eighteen ounces of it.

Lute on your receiver again, and continue the distillation with a

greater degree of fire. There will come over an aqueous, acid liquor,

smelling strong of a sulphureous spirit, which is not inflammable. It

will be accompanied with undulating vapours; which being condensed will

form an oil, most commonly yellow, one part of which will float on the

surface of the liquor, and another will sink to the bottom.

Towards the end of the distillation of this acid liquor, and of the

yellow Oil of which it is the vehicle, that part of the mixture, which

is left in the retort and grown black, will begin to rise in froth.

Then suppress your fire at once: stop the distillation, and change your

receiver once more. When the vessels are grown pretty cool, finish your

distillation with a lamp-heat, kept up for twelve or fifteen days,

which in all that time will raise but a very little sulphureous spirit.

Then break your retort, in which you will find a black, solid mass,

like a Bitumen. It will have an acid taste, arising from a remainder of

the Acid imperfectly combined with Oil.

This artificial Bitumen may be freed from its redundant Acid, by

washing it in several waters. Then put it into a glass retort, and

distil it with a strong reverberated fire. You will obtain a reddish

Oil that will swim on water, much like the Oil obtained by distilling

the natural Bitumens. This Oil also will be accompanied with an aqueous

acid liquor. In the retort will be left a charred matter, which, being

put into an ignited crucible in the fire, burns for some time, and,

when well calcined, leaves a white earth.

The liquors that rise first in this distillation, and which we directed

to be kept by themselves, are a mixture consisting, 1. of a highly

dephlegmated Spirit of Wine, of a most fragrant smell; 2. of Æther,

which the Spirit of Wine wherewith it is united renders miscible

with water; 3. of a portion of Oil, which commonly rises with the

Æther, towards the end of the operation; 4. and sometimes of a little

sulphureous acid, if the receiver be not changed soon enough.

In order to separate the Æther from these other substances, put the

whole into an English retort, with a little Oil of Tartar _per

deliquium_ to absorb the Sulphureous Acid, and distil very slowly in

a sand-bath heated by a lamp, till near half the liquor be come over.

Then cease distilling; put the liquor in the receiver into a phial with

some water and shake it; you will see it rise with rapidity to the

upper part of the phial, and float on the surface of the water: this is

the Æther.

_OBSERVATIONS_.

This operation is only a decomposition of Spirit of Wine by means of

Oil of Vitriol. In the preceding process we saw that this Spirit, which

consists of three essential principles, _viz._ an Oil, an Acid, and

Water, cannot be deprived of one of them without being at the same time

decomposed; the two others that remain having, by such separation, lost

the bond of intimate union and connection that was between them. We saw

also that Spirit of Wine, when mixed and digested with a very caustic

Fixed Alkali, and several times distilled from it, deposites its Acid

in that Salt: and hence it comes that the Oil and the Water, being

deprived of the principle which was the bond of their union, separate

from each other, and appear in their natural forms.

In the present experiment, the Vitriolic Acid decomposes the Spirit

of Wine in a different manner. We know that this Acid acts powerfully

on Oils; and that, when it is highly concentrated, as the operation

requires it should be, it seizes and attracts with surprising force the

moisture of all bodies that touch it. So that, when it is mixed with

Spirit of Wine, it acts at the same time both on the aqueous and on

the oily principle of that mixt. The rapidity and activity, wherewith

it rushes into union with these substances, produce the heat, the

ebullition, and the hissing noise, which we observe during the first

moments after their mixture.

The red colour, which the two liquors confounded together acquire after

some time, is owing to the combination of the acid with the oily part;

for it is known that Oils, as colourless as Spirit of Wine, such as the

Essential Oil of Turpentine, become of a brownish red when dissolved

by a concentrated Acid: and Kunckel observed, that, the more Oil there

is in Spirit of Wine mixed with Oil of Vitriol, the deeper is the red

colour it acquires on being so mixed. He even gives this experiment as

the certain means of discovering whether Spirit of Wine be more or less

oily; and he adds, that Spirit of Wine, which hath lost part of its Oil

by being rectified with Lime, acquires less redness than any other by

being mixed with Oil of Vitriol.

When the mixture hath acquired this colour, and before it undergoes

distillation, it appears like a homogeneous liquor. There is yet no

decomposition; or at least none that is perceptible; and the Vitriolic

Acid is united at the same time with the Oil, the Acid, and the

Water of the Spirit of Wine; that is, with the whole Spirit of Wine

in substance. This mixture, when made with three parts of Spirit of

Wine to one of Oil of Vitriol, is an astringent remedy much used in

hemorrhages, and known by the name of _Rabel's Water_.

The actual decomposition of the Spirit of Wine is effected by the

distillation. The first liquor, or the first portion of the liquor

that rises before the rest, hath the smell and all the properties of

Spirit of Wine. It is indeed part of the Spirit of Wine employed as

an ingredient in the mixture; but, being abstracted from a highly

concentrated Oil of Vitriol, which, of all known substances, attracts

moisture with the greatest power, it is perfectly freed of all its

unnecessary phlegm, and retains no more than what is a constituent part

thereof, as one of its principles, without which it would not be Spirit

of Wine.

The liquor that succeeds this first Spirit of Wine is of a different

nature. It may be considered as an Æther: for, though it be not a pure

Æther, it contains the whole of it: from this liquor only can it be

obtained; it is no other than an Æther mixed with some of the Spirit of

Wine that comes over first, and a little of the acid liquor which comes

afterward. Now the production of Æther is the effect of a beginning

decomposition of the Spirit of Wine: it is Spirit of Wine degenerated,

half decomposed; Spirit of Wine too highly dephlegmated; that is,

Spirit of Wine which hath lost a part of its essential phlegm, of that

phlegm which as a necessary principle made it Spirit of Wine: it is a

liquor still composed of oily parts mixed with aqueous parts, and on

that account must retain a resemblance of Spirit of Wine; but such that

its oily parts, not being dissolved and diffused among a sufficient

number of aqueous particles, are brought nearer to each other than

they should be to constitute perfect Spirit of Wine; on which account

it is not now miscible with water, but is as much nearer to the nature

of Oil, as it is removed from the nature of Spirit of Wine: it is a

liquor, in short, which, being neither Spirit of Wine nor pure Oil, yet

possesses some properties in common with both, and is consequently to

be ranked in the middle between them.

This explanation of the nature of Æther, which I imagine was never

before given by any other, is the same that we proposed in our Elements

of the Theory of Chymistry, which may be consulted on this occasion.

An objection against this opinion may, perhaps, be drawn from an

experiment well known in Chymistry. It may be said, that, if Æther

were nothing but depraved Spirit of Wine, which ceases to be miscible

with water, because the loss it hath sustained of a portion of the

water necessary to its constitution hath disordered the proportion

which ought to subsist between its aqueous and oily parts, from which

proportion it derives that property, it would be very easy to change

Spirit of Wine into Æther by a method quite contrary to the usual

one; _viz._ by mixing Spirit of Wine with a sufficient quantity of

superfluous Oil: for it seems to be a matter of indifference whether

the proportion, between the aqueous and the oily parts of Spirit of

Wine, be changed by lessening the quantity of the former, as in the

common operation for Æther, or by increasing the quantity of the

latter, as is here proposed; and we can, by the last method, put these

two principles together in what proportion we please. Now it is certain

that, whatever quantity of Oil be dissolved in Spirit of Wine, it will

still remain miscible with water; and that, if Spirit of Wine thus

replete with Oil be mixed with water, it will unite therewith as usual,

and quit the Oil which it had dissolved.

This objection, though seemingly a very specious one, will be removed

with the utmost ease, if we reflect but ever so little on some of the

principles already laid down. We said, and we gave some instances

of it, that certain substances may be united together in sundry

different manners: so that from these combinations, though made in

the same proportions, there shall result compounds of very dissimilar

properties. The combination we are now considering is another evidence

of this truth. It is allowed that the proportion between the oily and

the aqueous parts may be exactly the same in Æther and in Spirit of

Wine replete with Oil; but it must also be owned that the manner in

which the Oil is combined in these two cases is very different.

That Oil, which at first is a constituting part of the Spirit of Wine,

and afterwards becomes a part of the Æther, is united with the other

principles of those mixts, that is, with their Acid and their Water,

by the means of fermentation, whereby it is much more attenuated, and

much more closely combined, than that with which Spirit of Wine is

impregnated by dissolution only. And accordingly this adventitious

Oil is so slightly connected with Spirit of Wine, that it is easily

separable from it by barely distilling it, or even mixing it with

water: whereas that which makes a part of the Spirit of Wine, as one of

its constituent principles, is united therewith in such a manner as not

to be separable from it by either of these methods, nor indeed without

employing the most vigorous and powerful agents for that purpose. So

that the chief differences between Æther and Oily Spirit of Wine must

be ascribed to the different manner in which the Oil is combined in

these two mixts: and, if a sufficient quantity of superfluous Oil could

be united with Spirit of Wine, in such a manner that, without being

soapy, it should not be separable therefrom by the affusion of water, I

make no doubt but such a Spirit of Wine would be perfectly like Æther,

so far as not to be miscible with water.

But let us return to our distillation, and trace the decomposition

of the Spirit of Wine by the Vitriolic Acid. We have shewn that the

Acid begins with attracting part of the Water which constitutes the

Spirit of Wine, by which means it changes the nature of this compound,

destroys its miscibility with water, and brings it as much nearer to

the nature of an Oil as it thereby removes it from the nature of Spirit

of Wine.

According to the theory laid down it is evident, that, if the Acid

continue to act in the same manner on Spirit of Wine thus depraved

and become Æther; that is, if it continue to draw from it the small

remaining quantity of the aqueous principle, to which it owes the

properties it still retains in common with Spirit of Wine, this must

produce a total decomposition thereof; so that the oily parts, being no

longer dissolved and divided by the aqueous parts, will be collected

together, unite, and appear under their natural form, with all their

properties. Now this is exactly the case. The Vitriolic Acid rises in

the distillation after the Æther; but considerably changed, because

it is loaded with the scattered remains of the decomposed Spirit of

Wine. It is in a manner suffocated by the Water it hath attracted from

the Spirit; which is the reason why it appears in the form of a very

aqueous acid liquor. It carries up along with it the Oil which it hath

separated from that Water: this is the Oil we took notice of in the

process, and it is consequently that very Oily principle which actually

constituted the Spirit of Wine. Lastly, by acting on this Oil also, it

takes up a portion of phlogiston, which renders it sulphureous.

What remains in the retort is also a portion of the Oil, that was

contained in the Spirit of Wine, now combined with some of the Acid;

which is the reason why it is black and thick. It is a compound much

resembling a Bitumen, and when analyzed yields the same principles we

obtain from native Bitumens, or from an Essential Oil thickened and

half burnt by its combination with concentrated Oil of Vitriol.

As to the Acid of the Spirit of Wine, some of it remains combined

with the Æther: but there is great reason to think, that, when the

Vitriolic Acid robs the Spirit of Wine of its aqueous part, it takes

up at the same time most of its Acid, which being itself very aqueous,

may be considered as pure water with respect to the concentrated Oil of

Vitriol, by which it is attracted, and with which it is confounded.

The properties which characterise Æther agree perfectly well with what

we have said of its nature, and of the manner in which it is produced.

It is one of the lightest liquors we know; it evaporates so suddenly,

that, if a little of it be dropt on the palm of your hand, you will

scarce perceive the part it touches to be wet by it; it is more

volatile than Spirit of Wine; which is not at all surprising, seeing it

differs therefrom only by containing less water, which is the heaviest

principle in Spirit of Wine.

Æther is more inflammable than Spirit of Wine; for, if any flame be

brought but near it, it immediately catches fire. The reason of this

is, that the oily parts of which it consists are not only as much

attenuated, and as subtile, as those of Spirit of Wine, but also in

a greater proportion with regard to its aqueous parts. To the same

cause must be attributed the facility with which it dissolves any oily

matters whatever.

Æther burns without smoke, as Spirit of Wine does, and without leaving

any coal or earthy matter behind; because the inflammable or oily parts

contained in it are, in this respect, disposed like those of Spirit of

Wine.

The properties of not being miscible with water, and of taking up

Gold dissolved in _aqua regis_, it possesses in common with Essential

Oils; but the latter property it possesses in a much more sensible

degree than any Oil: for Essential Oils sustain the Gold they thus

take up but a little while; whereas the Æther never lets it fall.

It seems the ancient Chymists were unacquainted with the Æther: or

at least, if they did know it, they made a mystery of it, according

to custom, and spoke of it only in enigmatical terms. Amongst the

moderns Frobenius, a German Chymist, seems to have been the first

who brought it to perfection. Godfrey Hankwitz, also a German, but

settled in England, made mention of it much about the same time in the

Philosophical Transactions. According to the latter, Mr. Boyle and Sir

Isaac Newton both knew the preparation of Æther, for which they had

each a different process. But none of these Chymists ever published an

exact and circumstantial account of a method by which this liquor might

be prepared: so that Messrs. Duhamel, Grosse, and Hellot, who have

since made several experiments for that purpose, and have discovered,

and communicated to the public, easy and certain methods of procuring

Æther, had no assistance in their labours but from their own skill and

sagacity; which gives them a just title to the honour of the invention.

Mr. Beaumé also, a very ingenious Artist in Paris, who hath bestowed a

great deal of pains on this subject, lately communicated to the Academy

a Memoir, which, among several very important observations, contains

the commodious and expeditious process above inserted. As there are

many experiments in Mr. Hellot's Memoir, agreeing perfectly well with

what hath been said concerning the decomposition of Spirit of Wine by

the Vitriolic Acid, we think it will be proper to take notice of them

here, and to examine them briefly at least.

The quantity, the colour, and the weight of the Oil, which rises in

the distillation at the same time with the aqueous acid liquor, are

various, according to the different proportions of Spirit of Wine and

Oil of Vitriol that are mixed together. Mr. Hellot observed that by

increasing the quantity of the Vitriolic Acid he obtained more of this

Oil, and less of the Ardent Spirit containing the Æther. The reason is

this: the more Oil of Vitriol you put in the mixture, the more Spirit

of Wine must be totally decomposed, and consequently the more of this

Oil will be obtained; which, as we have shewn, is one of the principles

resulting from the decomposition of Spirit of Wine.

"This Oil is also lighter or heavier, in proportion to the quantity of

Oil of Vitriol poured on the Spirit of Wine. That which arises from

mixing six, five, four, or even three parts of Spirit of Wine with one

part of concentrated Oil of Vitriol, always floats on the water, and

continues white. That which ascends from two parts of Spirit of Wine is

yellow, and most commonly sinks; and, lastly, that which is produced

from equal parts of these two liquors is greenish, and constantly falls

to the bottom."

Mr. Hellot remarks, on this occasion, that part of the Acid, by the

intervention of which this Oil is separated, unites therewith; and,

to the greater or smaller quantity of the Acid thus combined with the

Oil, he imputes its being more or less ponderous: which is the more

probable, as the heaviest Oil is always obtained from a mixture in

which the Acid bears the greatest proportion, and _vice versa_. Perhaps

the different specific gravity of Essential Oils is wholly owing to the

greater or smaller quantity of Acid they contain.

Mr. Hoffman hath made several observations on this Oil, which evidently

prove that it contains much Acid. He says, that, if it be kept for some

time in a bottle, it grows red, and loses its transparency; that its

agreeable aromatic taste becomes acid and corrosive; and that if you

hold it over the fire in a silver spoon, it corrodes it, and leaves

a black spot on it; and that it also corrodes Mercury, when heated

therewith in a matrass. To this Mr. Pott adds, that it makes a very

perceptible effervescence with Fixed Alkalis; and that being rectified

by those salts it loses all the acid properties observed by Mr. Hoffman.

Mr. Hellot obtained a still more considerable quantity of this Oil, by

adding three or four ounces of a Fat Oil to the mixture of Spirit of

Wine with the Vitriolic Acid. Now, as the Oil we are speaking of hath

the properties of Essential Oils, and is soluble in Spirit of Wine,

Mr. Hellot observes, that Oil of Vitriol by uniting with Fat Oils

converts them into Essential Oils: which agrees very well with our

opinion concerning the cause of the solubility of Oils in Spirit of

Wine; which, in the Memoir already referred to on other occasions, we

attribute to an Acid superficially and slightly united with Oils.

The Oil which thus rises, in distilling Spirit of Wine mixed with the

Vitriolic Acid, is known by the name of the _Sweet Spirit of Vitriol_.

This name is very improper, because it may suggest a notion that this

Oil derives its origin from the Vitriolic Acid, as some Chymists have

erroneously thought; whereas it comes entirely from the Spirit of Wine,

as we have shewn. If any reason can be assigned for keeping up the

name, it must be because of the considerable quantity of the Vitriolic

Acid that remains in the combination, and is dulcified by its union

with the Spirit of Wine.

This Oil is an ingredient in Hoffman's famous _Anodyne Mineral Liquor_.

That liquor is thought to be nothing but this very Oil dissolved, and

combined with the two liquors that rise first in the distillation, and

immediately before the sulphureous acid phlegm. It dissolves very

easily and quickly in those spirituous menstrua; so that, if you intend

to have it by itself, and to prevent its recombining with the liquors

that come off before, (which should be prevented, because it hinders

the separation of the Æther), you must take great care to change the

receiver as soon as the acid phlegm with which it rises begins to

appear.

We have seen that, by the methods which Mr. Hellot hath pointed

out, this Sweet Oil of Vitriol may be increased, both in weight and

quantity. In that ingenious Chymist's Memoir we also find some methods

of preventing it from rising in the distillation. They consist wholly

in the addition of some Absorbent bodies, which, he tells us, divert

the action of the Vitriolic Acid, at least in some measure, from the

inflammable part of the Spirit of Wine. One of these methods is as

follows.

"Put into Spirit of Wine as much soft Soap as it can dissolve: filter

it, and pour on it some of the heaviest and most concentrated Oil of

Vitriol: shake the mixture. The Soap will be instantly decompounded,

and its Oil will float on the surface; because the Vitriolic Acid robs

it of the Alkali, which renders it miscible with Spirit of Wine. Distil

it, and you will obtain but a very little of Rabel's water; which,

moreover, will have the disagreeable smell of a most rancid Oil. There

will afterwards ascend a great quantity of Spirit of Wine having the

same smell; then an aqueous, acid, and sulphureous liquor; but not a

drop of yellow Oil. Mean time there forms a bituminous fungus, of some

confidence, rising above the Oil of the Soap which floats on the rest

of the liquid."

Most of the Vitriolic Acid having been absorbed by the Alkali of the

Soap, in this experiment, as Mr. Hellot observes, it is not surprising

that it should not act upon the Spirit of Wine with so much efficacy as

to decompose it, and separate its Oil. For the same reason but a little

of Rabel's Water comes over, and almost all the Spirit of Wine rises

without undergoing any sensible alteration. The disagreeable smell of

those liquors comes from the Oil of the Soap, which, being naturally

heavy, remains behind in the retort, where it grows rancid and is

partly burnt.

The last experiment in Mr. Hellot's Memoir, of which we shall take

notice, is a peculiar process for preparing Æther; by means whereof,

with the help of an earthy medium, it is easy to distil the vinous acid

Spirit containing the Æther, without any sensible change of smell from

the beginning to the end of the operation; without its being succeeded

by an acid sulphureous liquor, oil, black scum, resin, or bitumen; and

without the necessity of taking any great care about the management of

the fire, as the liquor may always be kept boiling in the retort, and

distilled to dryness without any danger. This medium is common potter's

earth. Mr. Hellot puts six ounces thereof, well dried and pulverized,

into a large retort, with one pound of Spirit of Wine and eight ounces

of Oil of Vitriol. These he digests together three or four days. The

mixture acquires no sensible colour. He sets the retort in a sand-bath,

and continues the distillation to dryness with a moderate charcoal

fire. Excepting a few drops that rise first, and which are pure Spirit

of Wine, all the rest of the liquor that distils hath constantly the

smell of Æther: which is even somewhat more penetrating than that of

the vinous acid Spirit obtained without the intervention of this earthy

medium.

We have shewn, that the production of the æthereal liquor is owing to a

semi-decomposition of the Spirit of Wine effected by the Vitriolic Acid

during the distillation; that this Acid continuing to act, produces a

total decomposition, or perfect separation of the Oil and Phlegm of the

Spirit of Wine from each other; and that the Vitriolic Acid, uniting

with these two principles, forms the sulphureous phlegm, the fluid oil,

and the bituminous matter, all frequently mentioned above. Why then,

in this experiment of Mr. Hellot's, do we obtain only a Spirit of Wine

replete with Æther, while none of the other productions appear? The

reason is a very natural one, and very clear: it is this; the potter's

clay containing an earth of that kind which we called Absorbent,

because it possesses the property of uniting with Acids, that earth

joins with the Vitriolic Acid in the mixture, reduces it to a Neutral

Salt, and thereby prevents its continuing to act upon the Spirit of

Wine, as is necessary to the total decomposition thereof.

Mr. Hellot says on this occasion, "that part of the Vitriolic Acid

turning its action on this soluble earth or bole, which it finds in

the potter's clay, ceases to act on the inflammable principle of the

Spirit of Wine; that, consequently, as there is not an immediate and

continuous combination of these two substances, neither a resin nor a

bitumen can result therefrom. This is so true, that a great part of the

Oil of Vitriol may be afterwards recovered from the potter's clay as

colourless as when it was first used."

Mr. Hellot makes use of the following method for procuring the Æther

from the acid vinous Spirit obtained by this distillation. "You must,"

says he, "put all this liquor into a glass body, made of one piece

with its head; pour upon it, through the hole in the upper part of the

head, twice or thrice as much well-water, the hardest to the taste, and

the most impregnated with gypsum, that can be got. Very pure water, he

observes, produces much less Æther.

"If the vinous acid Spirit have such a sulphureous smell, as to

occasion a suspicion that it contains a little too much of a Volatile

Vitriolic Acid, you must add to the water two or three drams of Salt of

potash to absorb that Acid; and then distil with a lamp-heat.