Chapter V: Part I: Of the Distillation of Spirits (1)

By the Distillation of Spirits is to be understood the Art by which all inflammable Spirits, Brandies, Rums, Arracks, and the like, are procured from vegetable Substances, by the means of a previous Fermentation, and a subsequent Treatment of the fermented Liquor by the Alembic, or hot Still, with its proper Worm and Refrigeratory.

But as it is impossible to extract vinous Spirits from any vegetable Subject without Fermentation, and previous to this Brewing is often necessary, it will be requisite first to consider these Operations.

CHAP. I.

_Of Brewing, in order to the Production of inflammable Spirits._

By Brewing, we mean the extracting a Tincture from some vegetable Substance, or dissolving it in hot Water, by which means it becomes proper for a vinous Fermentation.

A Solution, or fermentable Tincture of this kind, may be procured, with proper Management, from any vegetable Substance, but the more readily and totally it dissolves in the Fluid, the better it is fitted for Fermentation, and the larger its Produce of Spirits. All inspissated vegetable Juices therefore, as Sugar, Honey, Treacle, Manna, _&c._ are very proper for this Use, as they totally dissolve in Water, forming a clear and uniform Solution; but Malt, for its Cheapness, is generally preferred in _England_, though it but imperfectly dissolves in hot Water. The worst sort is commonly chosen for this Purpose; and the Tincture, without the Addition of Hops, or Trouble of boiling it, is directly cooled and fermented.

But in order to brew with Malt to the greatest Advantage, the three following Particulars should be carefully attended to: 1. the Subject should be well prepared; that is, it should be justly malted, and well ground: For if it be too little malted, it will prove hard and flinty; and consequently, only a small Part of it dissolve in the Water: And, on the other hand, if too much malted, a great Part of the finer Particles, or fermentable Matter, will be lost in the Operation. With regard to grinding, the Malt should be reduced to a kind of coarse Meal; for Experience has shewn, that by this means, the whole Substance of the Malt may, through the whole Process, continue mixed with the Tincture, and be distilled with it; whereby a larger Quantity of Spirit will be obtained, and also great Part of the Trouble, Time and Expence in Brewing saved. This Secret depends upon thoroughly mixing, or briskly agitating the Meal, first in cold Water, and then in hot; and repeating this Agitation after the Fermentation is finished: When the thick turbid Wash must be immediately committed to the Still. And thus the two Operations of Brewing and Fermenting may very commodiously be reduced to one, to the no small Profit and Advantage of the Distiller.

The second Particular to be attended to, is, that the Water be good, and properly applied. Rain Water is the best adapted to Brewing; for it not only extracts the Tincture of the Malt better than any other; but also abounds in fermentable Parts, whereby the Operation is quickened, and the Yield of the Spirit increased. The next to that of Rain, is the Water of Rivers and Lakes, particularly such as wash any large Tract of a fertile Country, or receive the Sullage of populous Towns. But whatever Water is used, it must stand in a hot State upon the prepared Malt, especially if a clear Tincture be desired; but the greatest Care must be taken to prevent the Malt from running into Lumps or Clods; and, indeed, the best Way to prevent this, is to put a small Quantity of cold Water to the Malt first, and mix them well together, after which the remaining Quantity of Water may be added in a State of boiling, without the least Danger of coagulating the Malt, or what the Distillers call, making a Pudding.

It has been found by Experience, that a certain Degree of Heat is necessary to extract the whole Virtue of the Malt: This Degree may, by the above Method, be determined to the greatest Exactness, as the Heat of boiling Water may at once be lessened to any assigned Degree of Warmth, by a proper Addition of cold Water; due Regard being had to the Season of the Year, and the Temperature of the Air. This Improvement, with that mentioned above, of reducing the two Operations of Brewing and Fermentation to one, will be attended with considerable Advantage.

With regard to the proper Quantity of Water, it must be observed, that if too little be used, a viscid clammy Mixture will be produced, little disposed to ferment, nor capable of extracting all the soluble Parts of the Malt. On the other hand, too much Water renders the Tincture thin and aqueous, and by that means increases the Trouble and Expence in all Parts of the Operation. A due Medium, therefore, should be chosen; and Experience has shewn, that a Wash about the Goodness of that designed by the _London_ Brewers for Ten Shilling Beer, will best answer the Distiller’s Purpose. When a proper Quantity of Water is mixed with the Malt, the whole Mass must be well agitated, that all the soluble Parts of the Malt may often come in contact with the aqueous Fluid, which being well saturated after standing a proper time, must be drawn off, fresh Water poured on, and the Agitations repeated, till at last the whole Virtue, or saccharine Sweetness of the Malt is extracted, and only a fixed husky Matter remains, incapable of being dissolved by either hot or cold Water.

The third requisite Particular is, that some certain Additions be used, or Alterations made according to the Season of the Year, or the Intention of the Operator. The Season of the Year is very necessary to be considered. In the Summer, the Water applied to the Malt must be colder than in the Winter; and in hot sultry Weather, the Tincture must be suddenly cooled, otherwise it will turn eager; and, in order to check the too great Tendency it has to Fermentation, when the Air is hot, it will be necessary to add a proper Quantity of unmalted Meal, which being much less disposed to Fermentation than Malt, will greatly moderate its Impetuosity, and render the Operation suitable to the Production of Spirits, which, by a too violent Fermentation, would, in a great Measure, be dissipated and lost.

CHAP. II.

_Of Fermentation._

The tincture, or, as the Distillers call it, the Wash, being prepared, as in the foregoing Chapter, it is next to be fermented; for, without this Operation, no vinous Spirit can be produced.

By Fermentation is meant that intestine Motion performed by the instrumental Efficacy of Water, whereby the Salt, Oil and Earth of a fermentable Subject, are separated, attenuated, transposed, and again collected, and recomposed in a particular Manner.

The Doctrine of Fermentation, is of the greatest Use, and should be well understood by every Distiller, as it is the very Basis of the Art; and, perhaps, if more attended to, a much purer Spirit, as well as a greater Quantity of it, might be procured from the same Materials than at present. We shall therefore lay down a concise Theory of Fermentation, before we proceed to deliver the Practice.

Every fermentable Subject is composed of Salt, Oil, and a subtile Earth; but these Particles are so small, that, when asunder, they are imperceptable to the Senses; and, therefore, when mixed with an aqueous Fluid, they leave it transparent; neither have fermentable Bodies any Taste, except that of Sweetness.

These Particles are each composed of Salt, Oil and Earth, intimately mixed in an actual Cohesion, Connexion, and Union; and, therefore, when any one of those Principles too much abounds in any Subject, so that an intimate Union is prevented, the whole Efficacy of the Fermentation is either stopped or impaired, or at least limited to one certain Species.

This equal Connexion of Salt, Oil and Earth into a single compound Particle, forms a Corpuscle soluble in Water; or, to speak more philosophically, this compound Corpuscle is, by means of its saline Particles, connected with the aqueous Corpuscles, and moved up and down with them. But where these Corpuscles are not thus connected with the Water, a Number of them join together, and form either a gross, or a loose, chaffy, and spungy Matter.

When these compound Particles are diluted with a small Quantity of an aqueous Fluid, they feel slippery, clammy, and unctuous to the Touch, and affect the Taste with a kind of ropy Sweetness. And when a proper Quantity of the Fluid is added, a Commotion is presently excited, and afterwards a subtile Separation.

This Commotion and Separation first begins in the whole Substance; for before the Addition of Water, the Subject may remain in dry, solid, and large Pieces, as in Malt, Sugar, _&c._ which being reduced to Powder, each Grain thereof is an Aggregate of many smaller compound Corpuscles; these being put into Water, dissolve, and separately float therein, till at length, they become so small as to be invisible, and only thicken the Consistence of the Liquor.

These Corpuscles being thus separated from one another, there next ensues a Separation of their component Particles; that is, the Salt, the Oil, and the Earth, are divided by the Interposition of the aqueous Particles.

The first Commotion is no more than a bare Solution; for the saline Particles being easily dissolvable in Water, they are immediately laid hold of by the aqueous Particles, and carried about with them. But the succeeding Separation, or fermentative Motion, is a very different thing; for by this the saline Particles are divided from those of Oil and Earth, partly by the Impulse of the others in their Motion, and partly by the Force of the aqueous Particles, which are now continually meeting and dashing against them.

This Motion is performed by the Water, as a Fluid, or Aggregate of an infinite Number of Particles, in actual and perpetual Motion; their Smallness being proportionable to that of the fermenting Corpuscles, and their Motion, or constant Susceptibility of Motion, by Warmth, and the Motion of the Air, disposing them to move other subtile moveable Corpuscles also. The certain Agreement of Figure, or Size between the aqueous Particles, and those of the Salt in the fermentable Subject, tends greatly to increase this Commotion; for, by this means, they are readily and very closely connected together; and therefore move almost like one and the same compound Corpuscle; whilst the Water is not at all disposed to cohere immediately with either the Oil or Earth. And thus an unequal Concussion is excited in the compound Corpuscles of the fermentable Subject; which Concussion at length strikes out the saline Particle, loosens the others, and finally produces a Separation of the original Connexion of the Subject.

An aqueous Fluid, therefore, is the true, and indeed the only, Instrument for procuring a fermentable Motion in these compound Corpuscles of the Subject: For were an oily Fluid poured upon any fermentable Subject, no vinous Fermentation would ensue; as the Oil could neither give a sufficient Impulse on the compound Corpuscles, which are grosser than its own constituent Particles, nor divide the oily or saline Particles of the Subject from their Connexion with the others, which detain, and, as it were, envelope, or defend them from its Action.

The compound Corpuscles of the fermentable Subject being affected by the perpetual Motion of the Particles of the aqueous Fluid, a proper Degree of Motion is necessary, or that the Particles move with a proper Degree of Velocity, which principally depends on external Heat. A considerable Degree of Cold, indeed, will not absolutely prevent Fermentation, though it will greatly retard it; and a boiling Heat will prevent it still more. A tepid, or middle Degree of Heat between Freezing or Boiling, is therefore the most proper for promoting and quickening the Operation.

The Admission of Air, also, though not of absolute Necessity, yet greatly promotes and quickens the Action, as being a capital Instrument in putting in a proper Degree of Motion the oily Particles of the Subject. But whilst the Air thus contributes to hasten the Effect, it causes at the same time by its Activity some remarkable Alterations in the oily Particles; for it not only moves, but absolutely dissolves and displaces them from their original Connexions; and thus carries them off with itself from the whole Mass. And, therefore, though the Consideration of the Air does not so properly belong to Fermentation in the general, yet it does in particular; as having an accidental Power to alter every Species of this Operation: Consequently its Agency ought to be well understood, either to procure Alterations at pleasure in the fermenting Mass, or to prevent and correct impending Dangers.

The oily Particles thus separated and dissolved by the Air, are also elastic, though they probably derive that Property from their Intercourse with the Air itself, and their being rendered extremely minute.

When, therefore, an aqueous Fluid is added to a fermentable Subject exposed to a temperate Heat, a fermentative Struggle immediately arises, the saline Part of the compound Particles being dissolved by the continual intestine Motion of the Water, and carried up and down with it in all Directions, amidst an infinite Number of other Particles, as well fermentable, as aqueous ones; whence, by this Collision and Attrition, the saline Particles are dissolved, and separated from their Connexion with the oily and earthy. And as the oily Particles are the most subtle and elastic, they would, by this means, be thrown up to the Surface of the Liquor, and carried off by the Air, were they not closely connected with the earthy ones, whose Gravity prevents their Evaporation, and, by coming in contact with others of the same kind, form Aggregations, and sink down, with the oily Particles, to the Bottom. But before these can form a Bulk too large to be supported by the Water, many of the oily Particles are, by their frequent Collisions with the aqueous Fluid, separated from the earthy ones; and, by Degrees, more strongly connected again with the saline ones; whilst, on the other hand, the same saline Particles imbibe some of the earthy ones, which being left single, upon their Separation from the oily Particles, floated about separately in the Fluid.

And hence proceed the several different Consequences of Fermentation; _viz._ 1. From the Separation of the saline Particles of the fermentable Subject proceeds the tart, saline, or acid Taste of the Liquor; which is more sensible at first, before the Liquor is duly composed and settled, or the due Arrangement and Connection of the saline Particles with those of the oily and earthy Kinds, completed: After which the Liquor proves milder, softer, or less pungent. 2. From the oily Particles being set at liberty, proceeds the strong Smell of the Liquor, and the Head or shining Skin upon the Surface. 3. The earthy Particles collecting together in Clusters, cause the Fluid to appear turbid, and afterwards a visible earthy, or clay-like Matter to be precipitated: And some of the earthy Parts, in their Motion, arriving at the Head, or oily Skin on the Surface, cause it to thicken; and afterwards taking it down along with it, thus constitute the Lees which abound in Oil. 4. From this new Struggle or Collision, which is productive both of Solution, and a new Connection in the saline and earthy Corpuscles, proceeds the Ebullition in Fermentation. And, lastly, by the same repeated Coalition of the oily with the aqueous and saline Particles, the inflammable Spirit is produced.

Having thus laid down a concise Theory of Fermentation, we shall now proceed to the Practice.

The Wash being brought to a tepid, or lukewarm State in the Backs, a proper Quantity of a good-conditioned Ferment is added; but if the Ferment be solid, it should be previously broke into small Pieces, and gently thinned either with the Hand, Whisp, _&c._ in a little of the tepid Liquor. A complete and uniform Solution, however, should not be attempted, because that would greatly weaken the Power of the Ferment, or destroy its future Efficacy. The whole intended Quantity, therefore, being thus loosely mixed with a moderate Parcel of the Liquor, and kept in a tepid State, either by setting it near the Fire, or otherwise, and free from the too rude Commerce of the external Air; more of the insensibly warm Liquor ought to be added, at proper Intervals, till, at length, the whole Quantity is properly set to working together. And, thus, by dividing the Business into Parts, it may much more speedily and effectually be performed, than by attempting it all at once.

The whole Quantity of Liquor being thus set to work, secured in a proper Degree of Warmth, and defended from a too free Intercourse of the external Air, Nature itself, as it were, finishes the Process, and renders the Liquor fit for the Still.

By Ferments, we mean any Substance, which, being added to any rightly disposed fermentable Liquor, will cause it to ferment much sooner and faster than it would of itself; and, consequently, render the Operation shorter; in contradiction to those abusively called so, which only correct some Fault in the Liquor, or give it some Flavour. Hence we see, that the principal Use of Ferments is to save Time, and make Dispatch in Business; whilst they only occasionally, and, as it were, by Accident, give a Flavour, and increase the Quantity of Spirit. And, accordingly, any fermentable Liquor, may, without the Addition of any Ferment, by a proper Management of Heat alone, be brought to ferment, and even more perfectly, though much slower, than with their Assistance.

These Ferments are, in general, the Flowers and Fæces of all fermentable Liquors, generated and thrown to the Surface, or deposited at the Bottom, either during the Act of Fermentation, or after the Operation is finished.

Two of these are procurable in large Quantities, and at a small Expence; we mean, Beer-Yeast and Wine-Lees; a prudent and artificial Management, or Use of which, might render the Business of Distillation much more facile, certain and advantageous.

It has been esteemed very difficult, and a great Discouragement, in the Business of Distillation, to procure a sufficient Stock of these Materials, and preserve them at all times ready for use. The whole Secret consists in dexterously freeing the Matter from its superfluous Moisture; because in its fluid State, it is subject to a farther Fermentation, which is productive of Corruption; in which State it becomes intolerably fœtid and cadaverous.

The Method of exposing it to the Air till it has required a proper Consistence, is subject to great Inconveniencies; and so peculiar and careful a Management necessary, that it rarely succeeds.

The best Way, therefore, is to press it very slowly and gradually, in a thick, close, and strong Canvas Bag, after the manner of Wine Lees, by the Tail-press, till it becomes a kind of Cake; which, though soft, will easily snap, or break dry and brittle between the Fingers. Being reduced to that Consistence, and closely packed up in a tight Cask, it will remain a long Time uncorrupted, preserve its Fragrancy, and consequently, fit to be used for fermenting the finest Liquor.

The same Method is also practicable, and to the same Advantage, in the Flowers or Yeast of Wine; which may be thus commodiously imported from abroad: Or, if these cannot be procured, others of equal Efficacy may be procured from fresh Wine Lees, by barely mixing and stirring them into a proper warm Liquor; whence the lighter, or more volatile and active Parts of the Lees, will be thrown to the Surface, and may easily be taken off, and preserved, by the above-mentioned Method, in any desired Quantity. And hence, by a very easy Process, an inexhaustible Supply of the most useful Ferments may be readily and successively procured, so as to prevent for the future all Occasion of Complaint for want of them, in the Distiller’s Business.

Experience has demonstrated, that all Ferments abound much more in essential Oil, than the Liquor which produced them; and consequently they retain, in a very high Degree, the Smell and Flavour of the Subject. It is therefore requisite, before the Ferment is applied, to consider what Flavour is intended to be introduced, or what Species of Ferment is most proper for the Liquor.

The Alteration thus caused by Ferments is so considerable, as to render any neutral fermentable Liquor, of the same Flavour with that which yielded the Ferment. This Observation is of much greater Moment than will presently be conceived; for a new Scene is hereby opened, both in the Business of Distillation, and others depending upon Fermentation. It must, however, be observed, that its Benefit does not extend to Malt, treated in the common Method; nor to any other Subject but what affords a Spirit tolerably pure and tasteless: For, otherwise, instead of producing a simple, pure, and uniform Flavour, it causes a compound, mixed, and unnatural one. How far the fine Stiller may profit by it, well deserves his Attention; and whether our native Cyder Spirit, Crab Spirit, _&c._ which have very little Flavour of their own, may not, by this Artifice, be brought nearly, if not intirely, into the State of some foreign Brandies, so highly esteemed, is recommended to Experience.

It is common with Distillers, in order to increase the Quantity of Spirit, give it a particular Flavour, or improve its Vinosity, to add several things to the Liquor, during the Time it is in a State of Fermentation; and these Additions may properly be reduced to Salts, Acids, Aromatics, and Oils.

All rich vegetable Juices, as Treacle, Honey, _&c._ which either want a natural Acid, have been deprived of it, or contain it in too small a Quantity, will be greatly improved by adding, at the Beginning of the Operation, a small Quantity of the vegetable or fine mineral Acids; as Oil of Sulphur, Glauber’s Spirit of Salt, Juice of Lemons, or an aqueous Solution of Tartar. These Additions will either give, or greatly improve the vinous Acidity of the Subject, but not increase the Quantity of the Spirit, that Intention being performed by Aromatics and Oils.

All pungent Aromatics have a surprising Quality of increasing the Quantity of the Spirit, as well as in altering, or improving the Flavour; but their Use requires that the Fermentation should be performed in close Vessels. And if a large Quantity be intended to be added, Care must be taken not to do it all at once, lest the Oiliness of the Ingredients should check the Operation. But if the Flavour be the principal Intention, they should not be added till the Operation is nearly finished. After the same Manner a very considerable Quantity of any essential vegetable Oil may be converted into a surprisingly large Quantity of inflammable Spirit; but great Caution is here also necessary not to drop it too fast, or add too large a Quantity at a time, which would damp the Fermentation; it being the surest Method of checking, or totally stopping this Operation, at any Point of Time required. The best Method, therefore, of adding the Oil, so as to avoid all Inconveniencies, is to rub the Oil in a Mortar with Sugar, which the Chemists call making an _Olæosaccharum_, by which Means the Tenacity of the Oil will be destroyed, and the whole readily mix with the Liquor, and immediately ferment with it. The Distiller would do well to consider these Observations attentively, as he may thence form an advantageous Method of increasing the Quantity of Spirits, and at the same Time greatly improve their Quality and Flavour.

But in order to put these Observations in practice, particular Regard must be had to the containing Vessel in which the Fermentation is performed, the Exclusion of the Air, and the Degree of the external Heat or Cold.

With regard to the containing Vessel; its Purity, and the Provision for rendering it occasionally close, are chiefly to be considered. In cleansing it, no Soap, or other unctuous Body should be used, for fear of checking the Fermentation; and, for the same Reason, all strong alkaline Lixiviums should be avoided. Lime-water, or a turbid Solution of quick Lime may be employed for this Purpose, without producing any ill Effect; it will also be of great Service in destroying a prevailing acetous Salt, which is apt to generate in the Vessels when the warm Air has free Access to them; and tends to pervert the Order of Fermentation, and, instead of a Wine or Wash, produce a Vinegar. Special Care must also be had, that no Remains of Yeast, or cadaverous Remains of former fermented Matters, hang about the Vessels, which would infect whatever should be afterwards put into them; and cannot, without the utmost Difficulty, be perfectly cured and sweetened.

The occasional Closeness of the Vessels may in the large way, be provided for by Covers properly adapted; and, in the small way, by Valves, placed in light Casks. These Valves will occasionally give the necessary Vent to preserve the Vessel, during the Height of the Fermentation; the Vessel otherwise remaining perfectly close, and impervious to the Air.

It is a Mistake of a very prejudicial Nature, in the Business of Fermentation, to suppose, that there is an absolute Necessity for a free Admission of the external Air. The express contrary is the Truth, and very great Advantages will be found by practising according to this Supposition. A constant Influx of the external Air, if it does not carry off some Part of the Spirit already generated, yet certainly catches up and dissipates the fine, subtile, or oleaginous and saline Particles, whereof the Spirit is made, and thus considerably lessens the Quantity. By a close Fermentation this Inconveniency is avoided; all Air, except that included in the Vessel, being excluded. The whole Secret consists in leaving a moderate Space for the Air at the Top of the Vessel, unpossessed by the Liquor. When the Liquor is once fairly at work to bung it down close, and thus suffer it to finish the Fermentation, without opening or giving it any more Vent than that afforded it by a proper Valve placed in the Cask; which, however is not of absolute Necessity, when the empty Space, or rather that possessed by the Air, is about one tenth of the Gage; the artificial Air, generated in the Operation being then seldom sufficient to open a strong Valve, or at most not to endanger the Cask.

This Method may be practised to good Advantage by those whose Business is not very large; but it requires too much Time to be used by the large Dealers, who are in a manner forced to admit the free Air, and thus sustain a considerable Loss in their Quantity of Spirit, that the Fermentation may be finished in the small Time allowed for that Purpose. It may, however, be said, that the silent, slow, and almost imperceptible vinous Fermentation, is universally the most perfect and advantageous.

During the whole Course of this Operation, the Vessel should be kept from all external Cold, or considerable Heat, in an equal, uniform, and moderate Temperature. In the Winter, a Stove-Room, such as is common in _Germany_, would be very convenient for this Purpose; the Vessel being placed at a proper Distance from the Stove: But at other Seasons no particular Apparatus is necessary with us in _England_, if the Place allotted for the Business be but well defended from the Summer’s Heat, and the ill Effects of cold bleak northern Winds.

The Operation is known to be perfected when the hissing, or small bubbling Noise can be no longer heard, upon applying the Ear to the Vessel; and also by the Liquor itself appearing clear to Eye, and having a pungent Sharpness on the Tongue. And that it may fully obtain these Properties, and be well fitted to yield a pure and perfectly vinous Spirit by Distillation, it should be suffered to stand at rest in a somewhat cooler Place, if practicable, than that in which it was fermented; till it has thoroughly deposited and cleansed itself of the gross Lee, and become perfectly transparent, vinous and fragrant; in which State it should be committed to the Still, and the Spirit obtained will not only exceed that obtained in the common Way in Quantity, but also in Fragrance, Pungency, and Vinosity.

CHAP. III.

_Of Distillation in general._

Having in the two preceding Chapters laid down the best Methods of Brewing and Fermentation, we shall now proceed to the Method of Distillation.

And in order to lead our Readers methodically through the Path which lies before them, we shall begin with explaining the Principles of Distillation; or, the Method of extracting the spirituous Parts of Bodies.

To extract the Spirits is to cause such an Action by Heat, as to cause them to ascend in Vapour from the Bodies which detain them.

If this Heat be natural to Bodies, so that the Separation be made without any adventitious Means, it is called Fermentation, which we have already explained.

If it be produced by Fire, or other heating Power, in which the Alembic is placed, it is called Digestion, or Distillation: Digestion, if the Heat only prepares the Materials for the Distillation of their Spirits; and Distillation, where the Action is of sufficient Efficacy to cause them to ascend in Vapour, and distil.

This Heat is that which puts the insensible Parts of a Body, whatever it be, into Motion, divides them, and causes a Passage for the Spirits inclosed herein, by disengaging them from the Phlegm and the earthy Particles by which they are inclosed.

Distillation considered in this Light, is not unworthy the Attention and Countenance of the Learned. This Art is of infinite Extent; whatever the whole Earth produces, Flowers, Fruits, Seeds, Spices, aromatic and vulnerary Plants, odoriferous Drugs, _&c._ are its Objects, and come under its Cognizance; but we generally confine it to Liquids of Taste and Smell; and to the simple and spirituous Waters of aromatic and vulnerary Plants. With regard to its Utility, we shall omit saying any thing here, as we shall give sufficient Proofs of it in the Sequel.

CHAP. IV.

_Of particular Distillation._

Distillation is generally divided into three Kinds; the first is called Distillation _per ascensum_, which is when the Fire, or other Heat, applied to the Alembic, containing the Materials, causes the Spirits to ascend. This is the most common, and indeed almost the only kind used by Distillers.

The second is called Distillation _per descensum_; which is, when the Fire being placed upon the Vessel precipitates, or causes the Spirit to descend. This Kind is hardly ever used by Distillers, but to obtain the Essence or Oil of Cloves.

The third is termed Distillation _per latus_, or oblique Distillation; but this being used only by the Chemists we shall say nothing farther of it here.

With regard to the different Methods of Distillation, occasioned by the different Vessels, or Materials made use of to excite Heat, improperly called Distillation; they are of various Kinds, and shall be explained as they occur in the Work.

There are various Kinds of Distillation, some of which arise from the different Constructions of Alembics; such are the Distillation by the common Alembic, with a Refrigeratory, the Glass Alembic, the serpentine Alembic, and the Retort: Others are produced from the Heat surrounding the Alembic; such as the Distillation in _Balneum Mariæ_, the Vapor, the Sand, the Dung, and the Lime Baths.

These different Methods of Distilling, we shall explain in enumerating the Operations in which they are most proper; and proceed to treat of the different Forms of Alembics and their Constructions.

CHAP. V.

_Of_ ALEMBICS, _and their different Constructions._

The Alembic is a Vessel usually of Copper tined, which serves for, and is essential to all Operations in the Distillery.

There are several Sorts of Alembics, all different, either with regard to Matter or Form. As, the common Alembic with a Refrigeratory, the earthen and the glass Alembic, the _Balneum Mariæ_, and the Vapour-Bath Alembic.

Every one of these being of a different Construction, are also used in different Operations.

The common Alembic consists principally of two Parts, the lower Part called the Body, and the upper termed the Head.

The Body consists of two Pieces, the lower called the Cucurbit, and the upper the Crown. The Cucurbit or lower Part of the Body, is a kind of Receptacle proportioned to the Size of the Alembic, in which the Bodies to be distilled are placed.

The Crown, or upper Part of the Body, is also another Part of the Alembic; and is that Part of the Body to which the Head is immediately luted. But an Idea of these several Alembics will be much better attained from the following Figures, which represent them much stronger to the Imagination than is possible to be done by Words.

_Fig. 1._ Is a common Alembic, as it appears before it is placed in a Furnace, where _a_ is the Bottom, _b_ the Crown, _c_ the Head.

_Fig. 2._ Is the Body without the Head; _a_ the Rim or Top of the Crown where the Head is luted.

_Fig. 3._ The Head; _a_ the Rim where it is to be luted to the Body; _b_ the Nose, or End which is luted into the Worm.

_Fig. 4._ The Worm, as it appears when out of the Tub in which it is fixed when in use; _a_ the End into which the Still Head is inserted, _b_ that which conveys the Liquor into the Receiver.

_Fig. 5._ Two Stills at work in one Refrigeratory; _a_, _b_ the two Still Heads, _c_, _d_ the Bodies inclosed in the Brick-Work; _e_, _e_ the two Fire-Places; _f_, _f_ the two Ash-Holes; _g_ a Common Receiver; _h_ a Spout Receiver, called by Chemists a Separating-Glass, used in the Distillation of Herbs, in order to extract their essential Oil; _i_ a Crane for drawing the Water out of the Refrigeratory.

_Fig. 6._ A small Still with a Refrigeratory; _a_ the Body, _b_ the Head, _c_ the Refrigeratory filled with Water, _d_ the Receiver, luted to the Bec of the Alembic.

_Fig. 7._ A Glass Alembic to be used as a _Balneum Mariæ_; _a_ the Body, _b_ the Head, _c_ the Bec, which is to be luted to the Receiver, _d_ a Trivet on which it is standing in the Water.

_Fig. 8._ A proper Receiver for the Glass Alembic, called by Chemists a Bolt-Head, or Matrass.

_Fig. 9._ The Glass Alembic placed in a Copper Vessel; _a_ the Copper Vessel filled with Water, _b_ the Body of the Glass Alembic, _c_ the Head, _d_ the Receiver luted at _c_ to the Bec of the Alembic.

_Fig. 10._ A cold Still for distilling simple Waters; _a_ the Head, _b_ the Bec, or Nose, _c_ the Receiver, _d_ the Plate on which Herbs are laid.

_Fig. 11._ A Vessel for Digestion, called by Chemists a Pelican or circulatory Vessel; _a_ the Body, _b_ the Head, _c_, _c_ two Tubes, luted at _d_, _d_, by which the Liquor returns from the Head into the Body; _e_ a Furnace on which it is placed, _f_ the Fire-place, _g_ the Ash-hole.

_Fig. 12._ Another Receiver, used when it is necessary to lute it to the End of the Worm, in order to prevent the most volatile Parts from being evaporated, and lost.

CHAP. VI.

_Of the_ ACCIDENTS _that too often happen in performing the Processes
of_ DISTILLATION.

Among the Accidents which frequently happen in Distilling, the least of all is for the Operation to miscarry and the Ingredients to be lost.

And this being a Subject of the greatest Importance we shall treat it with all possible Accuracy.

All Accidents are occasioned by Fire, their primary Cause; by want of Attention they get too much Head, and Fear often suffers them to become irremediable.

The first Accident which may happen by the Fire, is when a Distiller, by too great a Heat, causes the Ingredients to be burnt at the Bottom of the Still; by this Means his Liquor is spoiled by an empereumatic Taste, and the Tin is melted off from the Alembic. An Empereuma resembles the Smell of burnt Tobacco, and is produced in Liquors by too great a Degree of Heat. To illustrate this, distil any Fruit, Flowers, or any Aromatic whatever; but especially something whose Smell is very volatile, draw off only the best, unlute the Alembic, and what remains in the Still, will be found to have a very disagreeable Smell; whence it follows, that if a little more had been drawn off, it would have spoiled what was before obtained.

If the Fire be too violent, the extraordinary Ebullition of the Contents causes them to ascend into the Head; and, if a Glass Alembic, they fall ignited into the Recipient; the Heat breaks it, the Spirits are dissipated, and often take Fire from the Heat of the Furnace.

If the Fire be too strong, the Bottom of the Still becomes red hot, the Materials inflamed, and consequently the Fire reaches the Recipient.

When an earthen Alembic is used, the closest Attention is requisite to keep the Fire from burning the Materials at the Bottom. The Head, which is always of Glass, bursts, and the Spirits are spilt, and often catch fire. And the Remedy becomes the more difficult, as Earth retains the Fire much longer than a common Alembic.

If the Alembic be not firmly fixed, it is soon put out of Order, falls down and unlutes itself; thus the Liquor is spilt, and the Vapour sets the Spirits on fire.

If all the Joints be not carefully luted, the Spirits at their first Effort issue through the least Aperture, run into the Fire, which is propagated into the Alembic by the Vapour.

In Distillations where the Phlegm ascends first, its Humidity penetrates the Lute, and loosens it, so that when the spirituous Vapours ascend, they are exposed to the same Accident.

Lastly, when the Recipient is unluted, especially if near full, without the greatest Circumspection the Spirits will be spilt, and so catch Fire.

Hitherto I have only given a simple Account of what daily happens to Distillers; but the Consequences of these Accidents are infinitely more terrible than the Accidents themselves; for an Artist to lose his Time, his Labour and Goods, is no small Matter; but it follows from what we have premised, that both his Life and Fortune are in danger from these Conflagrations. Instances of the former are too common, as well as those of the latter, relating to the Danger to which the Operator is exposed. They are evident, and we have seen very lately three Instances sufficient to intimidate the most sanguine. The Spirits catch, the Alembic and Recipient fly, and the inflamed Vapour becomes present Death to all who breathe it.

The Rectifiers, who perform the most dangerous Operations of Distillery, are particularly exposed to these terrible Accidents; the Fineness of the Spirit at the same time that it renders it more inflammable, also causes the Fire to spread with the greater Rapidity. And when their Store-houses are once on Fire, they are seldom or never saved.

Possibly I may be censured for my Conciseness on this Head; indeed the Importance of it requires the most particular Discussion; but intending to speak of the Methods proper to prevent these Accidents, I shall close this Chapter, with recommending the Subject of it to the serious Reflection of all concerned in Distillation. And it being hitherto omitted, though of all others it requires the Attention of the Distiller, I shall further observe, that these Operations should never be left to Servants. What can be expected from ignorant Persons? Fear will seize them, when the greatest Presence of Mind is requisite.————Let us now proceed to the Methods of preventing, or at least lessening their Effects.

CHAP. VII.

_Of the Methods of preventing Accidents._

To have informed the Reader of the Accidents which happen in Distilling, would have been of little Consequence, without shewing, at the same Time, the Methods of preventing them. In order therefore to fortify him against the Terror, which the foregoing Chapter may have excited, we will here point out the Remedies for all the Cases before specified.

To prevent Accidents, two Things especially must be known, and adverted to.

1. The Knowledge of the Fire, which depends on the Fuel, whether Wood or Coal.

2. The Manner of luting so as to prevent the Vapours from escaping through it, and by that Means of setting the whole on fire.

The hardest Wood generally makes the quickest Fire, such as Beech, Oak, Holm, Elm, _&c._ The white Woods, as the Ash, the Poplar, the Willow, and the Birch, make a milder Fire. This holds good also of the Coal made of these two kinds of Wood; and, consequently, the Nature of the Wood or Coals must determine the Fire, and the Action of this must be proportioned to the Effect intended to be produced by it. That is, the Capacity of the Alembic, the Matters to be distilled, and their Quantity. The same may also be said of Pit Coal, which is generally used in _England_.

It is evident, that the larger the Alembic, the more Fire is necessary. What has not been digested, also, requires more Fire than that which has been prepared by that Operation. Spices require a stronger Fire than Flowers; a Distillation of Simple Waters more than that of spirituous Liquors.

The surest Way of ascertaining the necessary Degree of Fire, is to regulate it by the Materials, as they are more or less disposed to yield them Spirits, _&c._ and this is done as follows. The Operator must not leave the Alembic, but attentively listen to what passes within, when the Fire begins to heat it. When the Ebulition becomes too vehement, the Fire must be lessened, either by taking out some of the Fuel, or covering it with Ashes or Sand.

It requires a long Experience in the several Cases, before a Distiller can acquire a competent Knowledge in this important Point. Nor is it possible to determine the Degree of Fire from the Quantity of Fuel; Judgment, assisted by Experience, must supply this Defect.

Every thing being determined with regard to the Degree of Fire, we shall now proceed to explain the Method of luting Alembics.

By the Term luting an Alembic, we mean, the closing the Joints through which the Spirits might transpire.

Lute is a Composition of common Ashes, well sifted, and soaked in Water; Clay, and a kind of Paste made of Meal or Starch are also used for this Purpose; which, as I before observed, is to close all the Joints, _&c._ in order to confine the Spirits from transpiring.

Good Luting is one of the surest Methods of preventing Accidents. An Alembic, where all Transpiration is prevented, having nothing to fear but the too great Fierceness of the Fire; and that may be regulated by the Rules already laid down.

The refrigerating Alembic is mostly used. The Body and the Head are joined to each other; but notwithstanding the greatest Care be taken in luting the Juncture, there will still be some imperceptable Interstice for Transpiration; and the least being of the greatest Consequence, a Piece of strong Paper, should be pasted over the Joint, and the Alembic never left, till the Spirits begin to flow into the Receiver, in order to apply fresh Paper, if the former should contract any Moisture. The Master himself should carefully attend to this, and whatever Precaution may have been previously used, the Eye must be constantly upon it.

The Alembic, when vinous Spirits are distilled, should be luted with Clay, carefully spread round the Junctures, in order to prevent all Transpiration; because the Consequences here are terrible; for when the Fire catches a large Quantity, it is often irremediable. Besides, as this Earth cracks in drying, it must be often moistened, and fresh applied, on the first Appearance of any Occasion for it.

The Retort is also luted with Clay; but as glass Retorts are also used, they are often coated with the same Clay, to prevent their melting by the Intenseness of the Fire.

Lastly, the earthen and glass Alembics are luted with Paper and Paste as above.——Having thus explained the great Consequence of Circumspection with regard to Luting, and the Degree of Fire, we shall now proceed to a third Method of preventing them, and close this Chapter with a short Observation on portable Furnaces; which is, That Alembics being never thoroughly secure on this kind of Furnaces, a Hook should be fastened to the Refrigerant for fixing it to the Wall.

CHAP. VIII.

_Of the Remedies for Accidents, when they happen._

Notwithstanding the best of Rules, and the strictest Observation, it is impossible entirely to prevent Accidents, and therefore it is of no less Importance to point out the Remedies on those Occasions.

The most essential, are Courage and Presence of Mind; Fear only increasing the Misfortune.

1. If the Fire be too violent it must be covered, but not so as totally to prevent its Action, as by that Means the Process of the Distillation would be interrupted, and render it more difficult and less perfect.

2. When the Ingredients burn, which you will soon discover by the Smell, the Fire must be immediately put out, in order to prevent the whole Charge of the Still being entirely spoiled, which would otherwise inevitably be the Consequence.

3. If the Spirits should catch fire, the first care is to unlute immediately the Receiver, and stop both the End of the Beak and Mouth of the Receiver with wet Clothes.

The Fire must then be put out, and if the Flame issued through the Luting, the Joints must be closed with a wet Cloth, which, together with Water, should never be wanting in a Distil-house.

4. If the Alembic be of Earth, and the Contents burn at the Bottom, the Fire must immediately be put out, the Alembic removed, and Water thrown upon it, till the Danger is over; and, for farther Security, covered with a wet Cloth.

5. If after all your Care in closing the Junctures to prevent Transpiration, you perceive any thing amiss, while the Spirits are ascending, apply Clay, or any other Composition, in order to stop the Aperture, and have always a wet Cloth ready to stifle the Flame, if the Spirits should take fire.

6. If the Heat detaches the Lute, or it becomes moist, immediately apply another, having always ready what is necessary for performing it. Should the Transpiration be so violent, that you cannot immediately apply a fresh Lute, clap a wet Cloth round the Joint, and keep it on firm and tight, till the Spirits have taken their Course. But if notwithstanding all your Efforts the Transpiration should increase, so that you fear a Conflagration, remove the Receiver as soon as possible from the Fire, and afterwards your Alembic, if portable; but if otherwise, put out the Fire immediately.

7. The Charge being worked off, be cautious in luting the Receiver, that nothing be spilt on the Furnace, and carry it to some Distance from it, that the Spirits exhaling may not take fire.

8. Lastly observe, that wherever a Remedy is required, there must be no Candle used; for the spirituous Vapours easily take fire, and propagate the Flame to the Vessels from whence they issue.

All that has been hitherto said concerns only the Management of the Alembic; but what remains is still more interesting, and relates to those who work it, that they may not, by conquering the Accident, destroy themselves.

On discovering any of the above Accidents, when the Flame has not yet reached the Spirits, let the Remedies already mentioned be applied, either with regard to the Lute, or the Violence of the Fire.

But if the Flame has reached the Alembic, the following Precautions are to be used.

The Operator must not approach the Alembic without a wet Cloth over his Mouth and Nostrils, it being immediate Death to inhale the inflamed Vapour.

In hastening to stop any Accident, be careful to approach the Side opposite to that whither the Air impels the Flame; for, without this Precaution you would be involved in it, and could not, without the utmost Difficulty, extricate yourself from it.

If notwithstanding this Precaution, the Eddy of the Air should force the Flame to your Side, quit the Place immediately, and do not return till its Direction be changed, always taking care to have a wet linen Cloth before your Nose and Mouth, and keep yourself on the Side opposite to the Direction of the Flame: And also to have another such Cloth, in order to smother the Flame, and close the Crevise through which the Spirits issue.

Should it be your Misfortune to be covered with inflamed Spirits, wrap yourself in a wet Sheet, which should be always ready for that Purpose. Self-Preservation is of too great Importance that any of these Precautions should be omitted in such Variety of Dangers.

If the Fire has acquired such a Head that it cannot be stopt, the Receiver must be broke, and the Alembic, if portable, thrown down; but no Person must be suffered to go near them, especially those who are Strangers to the Business.

In a desperate Case, like that of a large Quantity of rectified Spirit taking Fire, if Time permit, the Communication of the Beak of the Alembic with the Recipient, which is usually a Cask, must be cut off, by closely stopping the Bung; and be sure no Candle come near the Receiver, leaving the rest, as the Danger would be too great to expose ones self to the Flames of a large Charge, and the Distiller’s Safety should be principally considered.

I thought it my Duty to give my Reader these Informations, and hope that in the Practice of Distillation, he will find them of great Advantage.

CHAP. IX.

_On the Necessity of often cooling the Alembic, as another Means of
preventing Accidents._

The Refrigerant is so essential a Part of the Alembic, that for want of it several other Expedients are made use of to perform its Office, for cooling those whose Capacity, Brittleness, or lastly the Construction, will not admit of their having any.

The Refrigerant is usually in proportion to the Capacity of the Alembic, for which the following may serve as a Rule, that the Capacity of the Refrigerant should be to that of the Alembic, as 14 to 8.

The Necessity of cooling the Head of the Alembic is self-evident to all who have the least Knowledge of Distillation, as it condenses the Spirits, cools them, and causes them to flow into the Receiver, which, if of Glass, would otherwise be broken by the Heat; and consequently serves to prevent Conflagrations.

The Alembics of the _Balneum Mariæ_, and the Vapour Bath, ought also to have Refrigerants, like the common Alembic, unless they are of Glass.

Those of Earth and Glass are cooled, as we have already observed, with a wet Cloth, which is also used to cool the Head of other kinds of Alembics. But it is not difficult to contrive one which may be placed in a Refrigerant; such as the following.

To a common small Still apply and lute a Worm, or long tin or pewter Tube, forming several Circumvolutions, of the same Circumference with the Body, in order to give it some Elevation, place this Worm in a Refrigerant, proportioned to the Alembic. If the Capacity of this Alembic should make it bear too much on the Neck of the Matrass, it may be supported by a Trevit of the same Circumference as the Body itself: The Extremity of the Worm may have a Beak projecting beyond the Side of the Refrigerant, for conveying the Spirits into the Receiver.

This Apparatus will be attended with little Expence, will save the Distiller the Trouble of being perpetually cooling the Head of the Alembic, and is such a Safe-guard against Accidents, that if the Worm be well luted, nothing need be apprehended but from the Violence of the Fire.

This Method of Practice, therefore, is productive of three valuable Particulars: The first is, that by cooling the Spirits it preserves the Receiver, and obviates the Accidents arising from their Heat. The second is, that the Spirits being kept in a moderate Heat, the Transpiration is less, and consequently the Spirits procured by the Operation have more Taste, Smell and Fragrancy than they would otherwise have had.

Experience demonstrates, that when the Spirits flow hot into the Receiver, however attentive the Distiller may be to lute the Junctures of the Alembic, there will be a very sensible Evaporation, which even in simple Waters greatly depreciates the Goodness of the Liquor.

Lastly, the third is, that the Cooling of Alembics is what principally contributes to the Perfection of the Operation; because the Coolness of the Head precipitates the Phlegm, and in the Case of too great a Degree of Fire, and where the Ebullition is too vehement, if after taking away Part of the Fire, or covering it, the Ebullition should continue, the Head may be cooled with a wet Cloth, till the Ebullition is reduced.