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as all the other bodies of dissenters in that country taken together. (Report of Commissioners of Religious Instruction in Ireland, 1835.) [DODDRIDGE.]

It is an art equally applicable to both divisions of the organic kingdom, and indispensable alike to the discovery of the structure of plants and animals. The grounds on which, for the well-being of the community, every facility DISSEPIMENTS, the partitions in the inside of a fruit should be afforded to the cultivation of this art, as far as which are formed by the union of the sides of its constituent regards human dissection, have been already fully stated. carpels. Dissepiments are therefore necessarily alternate [ANATOMY.] It is satisfactory to observe that the preju- with the stigma. When partitions which do not bear this dices which formerly obstructed this practice are rapidly relation to the stigma occur in the inside of a fruit they are disappearing, and that even the most uneducated are begin-called phragmata or spurious dissepiments, as in the catharning to appreciate its great importance and its signal utility. DISSEISIN. [SEISIN.]

DISSENTERS, the general name for the various Protestant religious sects in this country that disagree in doctrine, discipline, or mode of worship with the established church. The Jews and Roman Catholics are not commonly called dissenters. The origin of Protestant dissent from the church of England is usually traced back to the year 1548, in the reign of Edward VI., when a controversy arose among the adherents of the new Reformation in consequence of the excellent Hooper (afterwards the martyr) scrupling to be consecrated as bishop of Gloucester in the customary canonical habit, which he deemed objectionable as a relic of Romanism. Hooper eventually received consecration without being attired in canonicals. At this time the two parties received the names of Conformists and Nonconformists. Very soon after that of Puritans came into use as the general appellation of the dissenters; and it continued to be that by which they were commonly distinguished down to the close of the civil wars in the next century. The toleration of the dissenters, even in the most limited extent, dates only from the Revolution; during the century and a half that elapsed between the Reformation and that event, with the exception only of the short period of the Commonwealth, during which first the Presbyterians and afterwards the Independents had the ascendency, they continued to be persecuted by a succession of restrictive and penal laws of almost constantly increasing severity. It has taken almost the century and a half more, that has passed since the revolution, to raise the dissenters from being a merely tolerated body to a free participation in the rights of their fellow subjects by the abolition of the Test and Corporation Acts, in 1828. If the relaxation of the marriage law, that has since taken place, shall be followed by the abolition of church rates, the dissenters will be placed as nearly on an equality in all respects with the adherents of the established church as it is possible that they should be, without the established church itself being abolished. In the early times of dissent the great classes of dissenters were the Presbyterians, the Independents, the Baptists, and the Quakers, and they still continue to be the most numerous sects, unless we are to include the Methodists, or followers of Wesley and Whitfield, some of whom are avowedly dissenters, and others not, and are also subdivided into Wesleyan Methodists, Primitive, &c. The minor sects of dissenters now make a long list; but many of them may be considered as only subdivisions of or included in the four leading denominations. From an examination of the best materials (which are however very imperfect) that exist for the statistics of dissent, Mr. Macculloch is inclined to think that the entire number of Protestant dissenters in England and Wales does not exceed 2,200,000, or, at most, 2,500,000, even including the Methodists, who may amount to about 1,200,000. (Statistical Account of the British Empire, ii., 413, 416.) But this estimate, we are inclined to think, is too low. The most numerous classes of dissenters in Scotland originated in a separation from the established church in 1740. They are called generally Seceders, and are divided into Burghers, Anti-Burghers, Original Burghers, and Original Seceders. There are also the body of dissenters called the Relief Church, who separated from the establishment in 1758. The only considerable body of Scottish dissenters of older standing, with the exception of the Episcopalians, are the Cameronians, or Reformed Presbyterian Synod, who are the representatives of the Covenanters of the seventeenth century. Mr. Macculloch calculates the whole number of dissenters in Scotland (exclusive of about 140,000 Roman Catholics) at about 360,000 or 380,000 per

sons.

In Ireland, exclusive of the Roman Catholics, who alone outnumber the adherents of the established church in the proportion of 74 to one, the principal dissenters are the Presbyterians, who are mostly confined to the province of Ulster. The Irish Presbyterians amount to between 600,000 nd 700,000, and are more than twenty times as numerous

tocarpus fistula where they are horizontal, and in verbena where they are vertical.

DISSONANCE, in music, a term synonymous with discord. [DISCORD.]

DISTANCE. The only remark which we need make upon this common word is that it is very frequently applied to angular distance, meaning the angle of separation which the directions of two bodies include. Thus the spectator's eye being at O, the angle AOB is the angular distance (frequently simply called the distance) of the two points A and B. In the apparent sphere of the heavens, distance always means angular distance. The term apparent distance is frequently applied in the same case.

DISTEMPER, an inferior kind of colouring used for both internal and external walls, but principally for the former, instead of oil colour, being a cheap substitute. It is composed of whitening mixed with size of a coarse quality, in the proportions of twelve pounds of whitening to one of size. The size is boiled and reduced to a proper working consistency by the addition of water, after which the colour is added to form the necessary tint. Coarser colours are used for distemper than are employed in oil painting and colouring. Scene painting is executed in distemper, and paper stainers employ distemper colour in printing and staining papers for walls. The colours used in these cases are however of a better quality, and the size employed is made from the hide of the buffalo, or parchment cuttings. The proportions of size and whitening in paper staining depend on the strength of the size. In five quarts of distemper, if the size is strong, one-fourth part will be sufficient; if weak, about one-half. In mixing the size and whitening much depends on the judgment of the workman. The distemper is used in a chilled state. Five quarts will stain about eighty-four yards of paper. DISTHENE, a variety of KYANITE.

DI'STICHOUS, a term in botany, signifies arranged in two rows, as the grains in an ear of barley, and the florets in a spikelet of quaking-grass.

DISTILLATION is a chemical process for applying a regulated heat to fluid substances in covered vessels of a peculiar form called ALEMBICS, in order to separate their more volatile constituents in vapour: and for condensing them immediately by cold into the liquid state, in a distinct vessel, styled a refrigerator.

The Arabians seem to have practised, in the remotest ages, the art of extracting the aromatic essences of plants and their flowers, in the form of distilled waters, to supply the luxuries of oriental baths. They are also supposed to have been the first to extract from wine a colourless intoxicating liquor by distillation. The term alcohol, now applied to such distilled spirit, and which is supposed to be Arabic*, appears at first sight to favour that idea, but as it was antiently employed to designate merely the extremity, tenuity, or impalpable state of pulverulent substances, it affords no just ground for the above conclusion. From certain passages in Pliny and Galen there can be no doubt that the Greeks and Romans were well acquainted with the distillation of aromatic waters. Indeed Nicander, a Greek poet and physician who lived 140 years before the Christian æra, employs the terms außig ambix and distillation in describing the preparation of rose-water. From ambix, which signifies a pot, the Arabic name alambic or alembic is derived. The words pot and poteen are used in the same way by the modern Irish to designate a still and its spirituous product. It is obvious that distillation must have been a familiar process to the countrymen of Avicenna, since, in his treatise of catarrh, he compares the human body to an alembic; he regards the belly as the cucurbit or body, and the head as its capital, through which the humours distil, passing off by the nostrils as its beak.

Arnoldus de Villa Nova, a chemical physician of the thir

the article al prefixed, signifies autimony reduced to a fine powder, and used The true etymology of alcohol is uncertain. The Arabic word kohl, with as a collyrium for the eyes,'

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teenth century, is the first author who speaks explicitly of an | sugar, and one-fifth into gum. A similar change is more
intoxicating spirit obtained by the distillation of wine, and rapidly effected upon starch by boiling its pasty solution
he describes it as a recent discovery. He considers it to be with one-hundredth part of its weight of sulphuric acid. The
the universal panacea so long sought after in vain. His recent discovery of diastase by Persoz and Payen has en-
disciple Raymond Lully, of Majorca, declares this adinirable abled us to effect this curious conversion with much greater
essence of wine to be an emanation of the Divinity, an certainty, and to a greater extent than was possible by the
element newly revealed to man, but hid from antiquity gluten or the acid. If 8 or 10 parts of ground malt be niixed
because the human race were then too young to need this with 100 parts by weight of starch previously diffused through
beverage, destined to revive the energies of modern decre- 400 parts of water, at 140° Fahr., and if this mixture be
pitude. He further imagined that the discovery of this kept at a temperature of from 158° to 166° for three or four
aqua vita, as it was called, indicated the approaching con- hours, the nearly insipid pasty liquor will become a limpid
summation of all things-the end of the world. However syrup, which may be evaporated by a gentle heat into an
much he erred as to the value of this remarkable essence, uncrystallizable sugar, capable of being used as a substitute
he truly foresaw its vast influence upon the condition of for ordinary sugar, not only in the vinous fermentation, but
man, since to both civilized and uncivilized nations it has in many operations of the confectioner. The same change
realized infinitely greater evils than were threatened in the which takes place upon pure starch in the above experi
fabled box of Pandora.
ment is effected in the process of mashing as carried on in
breweries and distilleries. A larger or sinaller proportion
of the fecula of the corn is thereby converted into sugar,
and thus brought into a state fit for producing alcohol by
fermentation.

In his 'Chemical Theatre,' written towards the conclusion of the thirteenth century, Raymond Lully describes the distillation of ardent spirits thus:

'Limpid and well-flavoured red or white wine,' says he, 'is to be digested during 20 days in a close vessel by the heat of fermenting horse-dung, and to be then distilled in a sand bath with a very gentle fire. The true water of life will come over in precious drops, which, being rectified by three or four successive distillations, will afford the wonderful quintessence of wine.'

To prove its purity,' adds he, if a rag be dipped in it, and kindled, it will not become moist, but consume away.' All the older writers imagined that aqua vitæ imbibed from the fire its inflammable, heating, and exhilarating qualities; so in order to increase these qualities to the utmost, they prescribed tedious and repeated warm digestions of the wine before it was put into the alembic, and an exceedingly slow distillation that each drop might come over instinct with fire.

In the present article we shall consider distillation solely in reference to the production of alcohol. The process, when applied to distilled waters, æthers, and oils, belongs to pharmacy, chemistry, perfumery, &c.

The subject naturally divides itself into two branches: 1, the formation of the alcohol; 2, its elimination from the ingredients with which it is mixed.

The only substances employed in this country in the manufacture of ardent spirits upon the great scale are different kinds of corn, such as barley, rye, wheat, oats, buckwheat, and maize. Peas and beans also have been occasionally used in small quantity. The principles in these grains from which the spirits are indirectly produced are starch and a little sweet mucilage, which, by a peculiar process called mashing, are converted into a species of sugar. It is the sugar so formed which is the immediate generator of alcohol, by the process of fermentation. Hermstädt estimated that two pounds of starch properly treated would yield one quart of whiskey, of specific gravity 0.9427. The following kinds of corn afford of spirits of the said strength the quantities annexed to them in the scale: 100 pounds of wheat 40 to 45 pounds of whiskey.

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We may therefore conclude, says Hermstädt, that 100 pounds of corn will yield, upon an average, 40 pounds of spirits of the above specific gravity. We shall presently see that 100 pounds or two bushels of corn produce much more alcohol in the British distilleries.

In mashing one or more kinds of corn, a greater or smaller proportion of malt is always mixed with the raw grain, and sometimes malt alone is used, as in the production of malt whiskey.

The process of malting is that incipient growth called germination, in which, by the disengagement of a portion of the carbon of the starch, in the form of carbonic acid, the ultimate vegetable elements become combined in such a proportion as to constitute a species of sugar. Malting is the most effectual method of converting starch into sugar. But it is known from the researches of Saussure, that if starch in solution be digested for some time at summer temperatures with gluten, it will undergo a remarkable change, nearly one-half being converted into a species of

The manufacture of whiskey or ardent spirits consists of three distinct operations: first, mashing; second, fermentation; third, distillation.

1. Mashing.-Either malt alone, or malt mixed with other grains, and coarsely ground, is put into the mash-tun, along with a proper proportion of hot water, and the mixture is subjected to agitation by a mechanical revolving apparatus, exactly similar to that employed in the breweries for the manufacture of beer. When malt alone is used, the water first run into the mash-tun among the meal has usually a temperature of 160° or 165° Fahrenheit, but when a considerable proportion of raw grain is mixed with the malt, the water is let on at a lower temperature, as from 145° to 155°, for fear of making such a pasty magma as would not allow the infusion or worts to drain readily off.

The following are the quantities of malt and raw grain mixed which have been found to afford a good product of whiskey in a well-conducted Scotch distillery:

252 bushels of malt, at 40 pounds per bushel.
948 do.
do.
barley, 533
oats, 47 do.
rye,
533 do.

150

do.

150

do.

1500

do.

do.

From each bushel of the above mixed meal 2 gallons of proof whiskey (specific gravity 0.921) may be obtained, or 183 gallons per quarter. A few distillers are skilful enough to extract 20 gallons from a quarter of that mixture. Ten imperial gallons may be considered a fair proportion of water to be introduced into the mash-tun for every bushel of meal at the first infusion. After two or three hours' agitation, the whole is left to repose for an hour and a half, and then the worts are drawn off to about one-third the volume of water employed, the rest being entangled in a pasty state among the farina. About two-thirds of the first quantity of water is now let into the tun, but at a temperature somewhat higher, and the mashing motion is renewed for nearly half an hour. A second period of infusion or repose_ensues, after which these second worts are drawn off. infusions must be cooled as quickly as possible down to the temperature of 80° or 70° Fahr., otherwise they are apt to run into the acetous fermentation by the rapid absorption of atmospheric oxygen. This refrigeration is usually effected by exposing the wort for some time in large shallow cisterns, called coolers, placed near the top of the building, where it may be freely exposed to the aerial currents. But it is sometimes cooled by being passed through serpentine tubes surrounded with cold water, or by the agency of ventilators blowing over its surface in extensive cisterns only three or four inches deep.

Both

After the second wort is drawn off, a third quantity of water, fully as great as the first, but nearly boiling hot, is run into the mash-tun, and well incorporated with the magma by agitation; after repose, this third wort is also drawn off, cooled, and either directly mixed with the preceding worts, or after it has been concentrated by boiling down; in most cases however it is reserved, and used in stead of water for the first infusion of a fresh quantity of meal.

As a revenue of five and a half millions sterling is derived from the whiskey distilleries, their operations are sub

!

jected to a very strict code of regulations, which are ad-
ministered and enforced by the excise. One of these pre-
scribes the range of specific gravity at which the worts may
be lawfully let down into the fermenting tuns. The dis-
tiller must give notice to the excise officer in attendance,
before commencing a round, whether he intends to distil
from malt alone, or from a mixture of it with raw grain,
and of the density he intends his worts to be when intro-heit's scale. From the appearance of the froth or scum the
duced into the fermenting backs. He may change this no-
tice at the end of a month or six weeks, when, upon another
notice of six days, he may change his specific gravities. In
England the law restricts the distiller to the densities be-
tween 1.050 and 1.090; in Scotland, between 1.030 and
1.075, which, for brevity's sake, are called 50, 90, 30, and |
75, omitting the 1.000 common to them all. At these den-
sities the quantities of solid saccharum contained in one
barrel of 36 imperial gallons, are 47.25 lbs., 85 lbs., 28 lbs.,
and 70.3 lbs. respectively.

The mashing and fermentation are jointly called brewing, and the period in which they are carried on is by law kept quite distinct from the distilling period, the one occupying usually one week, and the other another in rotation. About 150 gallons of wort or wash are obtained from each quarter of corn employed.

stirrer. When by the attenuation the density is diminishea to 1.035 one half gallon more is added, and another half gallon at the density of 1.025, after which the worts usually receive no further addition of yeast. The temperature of the fermenting mass rises soon after the introduction of the yeast 8 or 10 degrees, and sometimes more; so that it reaches in some cases the 85th or 90th degree of Fahrenexperienced distiller can form a tolerably correct judgment as to the progress and quality of the fermentation. The greatest elevation usually takes place within thirty-six hours after the commencement of the process. The object of the manufacturer of spirits is to push the attenuation as far as possible, which so far differs from that of the beer-brewer, who wishes always to preserve a portion of the saccharine matter undecomposed to give flavour and body to his beverage. The first appearance of fermentation shows itself by a ring of froth round the edge of the vat usually within an hour after the addition of the yeast; and in the course of five hours the extrication of carbonic acid from the particles throughout the whole body of the liquor causes frothy bubbles to cover its entire surface. The temperature meanwhile rises from 10 to 15 degrees according to circumstances. The greater the mass of liquid, the lower the temperature at which it was let down into the tun, and the colder the surrounding atmosphere, the more slowly will the phenomena of fermentation be developed under a like proportion of yeast and density of the worts. In general large vats afford a better result than small ones, on account of the equality of the process. It is reckoned good work when the specific gravity comes down to 1.000, or that of water; and superior work when it falls 4 or 5 below it, or to 0.995.

The first of the above worts will have generally the density of 1.078 when the grain is good and the mashing is well managed, and the second a density of 1.054, so that the mixture will have a specific gravity somewhat above 1.060, and will contain about 60 pounds of extract per barrel. Now, by the excise rules, 100 gallons of such wort ought to yield one gallon of proof spirit for every five degrees of attenuation which its specific gravity undergoes in the fermenting fun, so that if it falls from 1.060 to 1.000, 12 gallons of proof spirit are supposed to be generated, and must be accounted for by the distiller. If he understand his business well, he will be able to produce from 5 to 10 per cent. more than the law requires. Mr. Smith, in his examination before the Molasses Committee of the House of Commons in 1831, states that in one year, reckoning by computation from the above data, he showed produce for 60,000 or 70,000 gallons more than the presumed quantity, and paid duty accordingly; and that in 1830 he was charged for 80,000 gallons of spirits actually produced beyond the presumptive charge, according to the attenuated gravity of the worts. In consequence of an alteration in the excise laws about twelve years ago, the distillers were allowed to ferment worts of less density than they previously could, and have been able to effect a more productive fermentation. They have been also enabled thereby to reduce the proportion of malt in the mixed meal. Formerly they were accustomed to use three parts of malt to four parts of barley, or two to three, but they soon diminished the malt to one-fifth, and Mr. Octavius Smith, the eminent distiller of Thames latterly to one-eighth, or one-tenth, of the whole grain. Bank, states in his examination before the Molasses ComOne principal use of malt, besides its furnishing the sac-mittee, that the acetous fermentation is always proceeding charine ferment called diastase, is to keep the mash magma porous, and facilitate the drainage of the worts.

The cost at which whiskey may be made in England is thus stated by Mr. Smith:-When barley is 388. per quarter, he reckons that one gallon of proof spirits costs 28. for corn or meal, 1s. 2d. for the charge of manufacturing, 2d. as the duty on malt employed, and 78. 6d. as the duty on spirit, amounting altogether to 10s. 10d. If we consider that from 18 to 20 gallons of proof spirits may be made from eight bushels or one quarter of mixed grain, we must think this statement of Mr. Smith's somewhat overcharged. Indeed good proof spirits may be bought from some distillers at a considerably less price, which proves either that they can manufacture the article more economically, or that they make a profit at the expense of the revenue.

II. Fermentation.

This is undoubtedly the most intricate, as it is the most important process in distillation, but unfortunately one hitherto studied with too little regard to scientific precision by the distiller. Experiments have proved that the quantity of saccharine matter converted into alcohol is dependent upon the proportion of ferment or yeast introduced into the worts; if too little be used a portion of the sugar will remain undecomposed, and if too much, the spirits will contract a disagreeable taste. In general, the worts are let down at the specific gravity of 1.050 or 1.060, and at a temperature varying from 60° to 70° Fahr., and for every 100 gallons one gallon of good porter yeast is immediately poured in and thoroughly incorporated by agitation with a

After thirty-six hours upon the moderate scale the yeasty froth begins to subside, and when the attenuation gets more advanced, the greater part of it falls to the bottom on account of its density relatively to the subjacent fluid. In from forty-eight to sixty hours the liquor begins to grow clear, and becomes comparatively tranquil. It has been deemed advantageous towards the perfection of the fermentation to rouse up the wash occasionally with a proper stirrer, and in some cases to increase its temperature a few degrees by the transmission of steam through a serpentine pipe coiled round the sides of the vat. Some have imagined that a considerable portion of spirit is carried off by the great volume of carbonic acid evolved, and have proposed to save it by covering the vats air tight, and conducting the gas through a pipe in the lids into a vessel containing water. The economy of this apparatus is not worth the expense and trouble which it occasions. The distillers content themselves with enclosing their vats after the first violence of the action under tolerably tight covers.

simultaneously with the vinous fermentation; for judging by the usual tests there is always a slight degree of acidity in fermenting wash; that vinegar is in fact forming along with alcohol, or that while the attenuation is increasing, acetic acid is being formed. This important fact, which agrees with our own experience, serves to show how very fallacious a test the attenuation or diminution of density is of the amount of alcohol generated and existing in a fermented wash. The acetic acid along with the undecomposed mucilaginous starch may, in fact, so far counteract the attenuating effect of the spirits as to produce a specific gravity which shall indicate 10 or 15 per cent. less spirit than is actually present in the wash. Hence the excise officers should be instructed to use test-stills in order to verify upon a small aliquot part the real quantity of distillable alcohol contained in each back of wash. After due agitation of the wash three samples should be taken by the dipping cylinder, or sinking-jar, one from the bottom, one from the middle, and one from the top; which being mixed and distilled would denote exactly the whole quantity of spirit that could possibly be extracted.

This test-still was clearly described and forcibly pressed upon the attention of the exchequer by Dr. Ure in his several examinations before the said Molasses Committee. The distillers in general, as might have been expected, scouted the idea of the possibility of ascertaining the quantity of spirits in a large back, from the distillation of a quart or a gallon of the wash; but Mr. Steel showed that by the distillation of 1000 grains in a glass retort

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(about one-tenth of a pint), he had obtained a produce | grain distillers. The main defect lies undoubtedly in the of spirit corresponding very nearly with the result of very imperfect saccharification of the fecula of the corn the distillation of ten gallons of the same wash in a in the mashing process, which, in our opinion, would reproper still. And Mr. O. Smith, when closely questioned, quire to be entirely remodelled, and conducted upon sounder admitted that means might be devised to enable an and more scientific principles. excise officer to perform the above analytical distillation with as great precision as the scientific man who had contrived the apparatus for him. The prevent've check, or attenuation, as it is called, which the excise apply to the fermented wash, is good for very little against a fraudulent distiller, because he can so easily introduce immediately before the visit of the officer, towards the end of the fermentation, such a quantity of salt as will so alter the density as completely to disguise and conceal seven or eight per cent. of the spirit, without in the least injuring its quality in the act of distillation. In fact, Mr. O. Smith acknowledges to its full extent the futility, or rather nullity, of that check, for he says, 'I conceive that any check which does not approximate any nearer to the fact than that just alluded to (the attenuated gravity), is almost useless, inasmuch as a distiller willing to evade the duty, could do so, as the difference between the charge of the saccharometer and the actual spirit produced, allows ample room for the most exorbitant smuggler.' * Mr. William Baker, surveying general examiner of excise, describes a mode of smuggling the spirits which would enable the distiller to make the quantity run off coincide with the quantity shown by the above fraudulent density. There was a pipe fastened before it came to the end of the worm, and it was carried through the wall into another part of the building. Any person may perceive how easy it is, with the actual distillatory apparatus, to lead a small branch tube from any point of the worm through the side or bottom of the worm-tub into a concealed subterraneous receiver.

In the huge fermenting vats used by the corn distillers of this country, the fermentation goes on far more slowly than when conducted upon the moderate scale referred to in the account of this process given above. About 1 gallon of yeast is added at first for every 100 gallons of wort, and a half gallon additional upon each of the succeeding four days, making in the whole 3 per cent.; when less can be made to suffice, the spirits will be better flavoured. The fermentation goes on during from six to twelve days, according to the modifying influence of the circumstances above enumerated. After the fifth or sixth day, the tuns are covered in, so as to obstruct, in a certain degree, the discharge of the carbonic acid, as it is supposed that this gas in excess favours fermentation. The temperature is usually greatest on the fourth or fifth day, when it sometimes rises to 85° Fahr., from the starting pitch of 60° or 56°. Whenever the attenuation has reached the lowest point by the hydrometer, the wash ought to be distilled, since immediately afterwards the alcohol begins to be converted in o acetic acid. This acidification may be partially repressed by the exclusion of atmospheric oxygen.

III. Distillation.

In 15

There is no chemical apparatus which has undergone so many metamorphoses as the still and condenser. simplest form it has been already represented and described. [ALEMBIC.] It may be considered to have reached its highest point of perfection, as to power and rapidity of work, in Scotland, when the distillers paid a stipulated sum per annum to the revenue for the privilege of a still of a certain size, and when therefore they derived a profit proportionable to the quantity of spirits they could run off in a given time. In the year 1799, from a report presented to the House of Commons, it appears that the Scotch distillers at that time were able to work off 80 gallons of wash in eight minutes, and the duty was levied accordingly; but very soon afterwards they contrived means of doing the same thing in about three minutes. The stills made for such rapid operation were shallow, and exposed a great surface to the fire. One of them is figured and described in Ure's Dictionary of Chemistry.' Since the year 1815, the whiskey duties have been levied on the quantity distilled, independent of the capacity of the still. This change has introduced a modification in the distilling apparatus, with the view of combining purity of product with economy of time. The body of the still is still comparatively flat, so as to expose a large surface to the fire; but the tapering upper part, corresponding to the capital of an alembic, is made very long, rising sometimes 15 or 20 feet before it terminates in the worm pipe or refrigeratory for condensation.

It is curious to contrast the actual insecurity of the re-
venue from the distillation of whiskey with the multiplicity
of precautions taken to prevent frauds; self-interest on the
one hand being so much stronger and sharper than duty on
the other. 'Examinations with us are constantly making; for
example, we are surveyed this morning at six o'clock, the
officers take their accounts and gauges, make calculations,
and do a great deal of work, occupying several hours: at ten
o'clock they again survey, going over the whole ground,
where they continue a considerable time, frequently until
the succeeding officer comes on duty: at evening too another
survey takes place, similar to the former, but not by the
same people; then at evening, six, the survey is repeated:
at evening, ten, there comes another survey, by an officer
who had not been engaged in any of the previous surveys
of that day. He is not relieved until morning, six, of the
day following; in addition to which, we are subject to
frequent and uncertain visits of the surveyor and general
surveyor: we are never out of their hands.'

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It is computed that every 5 degrees of attenuation, as it is called, that is, every diminution of the number 5 upon the specific gravity in the third place of decimals, ought to produce 1 per cent. of proof spirit, or 1 gallon out of 100, as formerly stated; so that if the wort be set at 1.055, and come down to 1,000, 11 gallons of proof spirits are chargeable upon each 100 of such wash. In the fermentation of sugar worts, 1 gallon of proof spirits was calculated for every four similar degrees of attenuation. But distillation from sugar or molasses-wash is now illegal. With corn-wash, there is never more than four-fifths of the saccharine matter decomposed into alcohol and carbonic acid, in the best-managed fermentation, and frequently indeed much less. In fact, each pound of real sugar may be resolved by a successful process into half a pound of alcohol, or into about one pound of proof spirit, From these receivers the various qualities of spirit, low and hence as a solution of sugar at the density of 1060, con- wines, and faints, are, for the purpose of redistillation, tains 15 per cent. by weight, or 16 per cent. by measure, pumped up into charging backs, from which they are run which is nearly 1.7 pounds per gallon, it should yield in gauged quantities into the low-wine and spirit stills. nearly 170 pounds from 100 gallons, or 180 pound measures The pumps afford many facilities to the fraudulent distiller equal to 18 gallons of proof spirit; whereas 100 gallons for abstracting spirits without the cognizance of the excise, of corn-wash, fermented at the above density, are computed and thus injuring at once the fair dealer and the revenue. by the excise law to yield only 12 gallons, and seldom pro- It would be easy to arrange a distillery so that pumps duce more than 13 and a small fraction. There is thus would be quite superseded, with their numerous joints and therefore a wide difference between the produce of spirit screws, and to conduct the spirituous liquids from the ap from real saccharine matter as fermented by the man of propriate receivers to the chargers and stills, on successive science, and the produce obtained by our best malt and levels, through a series of pipes, without external orifice:

Great distilleries are usually mounted with two stills, a larger and a smaller. The former is the wash still, and serves to distil from the fermented worts a weak crude spirit called low wines; the latter is the low-wine still, and rectifies by a second process the product of the first distillation. In these successive distillations a quantity of fetid oil, derived from the corn, comes over along with the first and last portions received, and constitutes by its combination what is styled the strong and weak faints in the language of the distilleries. These milky faints are carefully separated from the limpid spirit by turning them as they begin to flow from the worm-end into distinct channels, which lead to separate receivers.

Report on the use of Molasses, &c., 1831, p. 185, Q. 2720.

+ Ibid., p. 179, Q. 2612.

Thomas Smith, Esq., of Whitechapel-road, distiller, in Molasses Committee Report, p. 148, Q. 2199. P. C., No. 534.

One of the greatest improvements in modern distillation is the accomplishment of this essential analysis of the impure spirit at one operation. Chemistry had been long

VOL. IX.-E

familiar with the pneumatic apparatus of Woulfe, without thinking of its adaptation to distillery apparatus, when Edouard Adam, an illiterate operative, after attending by accident a chemical lecture at Montpellier, where he saw that apparatus, immediately employed it for obtaining fine brandy, of any desired strength, at one and the same heat.' He obtained a patent for this invention in July, 1801, and soon afterwards was enabled by his success to set up in that city a magnificent distillery, which attracted the admiration of all the practical chemists of the day. In November, 1805, he obtained a certificate of improvements whereby he could extract from wine, at one process, the whole of its alcohol. Adam was so overjoyed after making his first experiments, that, like another Archimedes, he ran about the streets telling every body of the surprising results of his new invention. About the same time, Solimani, professor of chemistry at Montpellier, and Isaac Berard, distiller in the department of Gard, having contrived two distinct systems of apparatus, each most ingenious, and obtaining results little inferior to those of Adam, became in consequence formidable rivals of his fame and fortune.

Into the description of these stills, of those of Derosne, Baglioni, &c., on the continent, or of their many modifications in this country, the limits of this article do not allow us to enter. In the treatises of Lenormand and Dubrunfaut, the construction of stills is described with a minuteness of detail sufficient to satisfy the most curious inquirers. We shall content ourselves with investigating the scientific principles of a perfect spirit still, and with a delineation of its outlines.

The boiling point of alcohol varies with its strength, in conformity with the numbers in the following table.

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rectifier for intercepting the greater part of the watery particles, and the whole of the corn oil; and third, the refrigerator. Such a construction is represented in fig. 1, 2, and 3, in which the resources of the most refined French stills are combined with a simplicity and solidity of construction suited to the grain distilleries of the United Kingdom. Three principal objects are obtained by this arrangement: first, the extraction from fermented wort or wine, at one operation, of a spirit of any desired cleanness and strength; second, a great economy of time, labour, and fuel; thud, freedom from all danger of blowing up or boiling over by mismanaged firing. When a mixture of the alcohol, water, and essential oil, in the state of vapour, is passed upwards through a series of winding passages, maintained at a regulated degree of heat, from 170° to 180°, the alcohol alone, in notable proportion, retains the elastic form, and proceeds onward into the refrigeratory tube, in which these passages terminate, while the water and the oil are in a great measure condensed and retained in these passages, so as to drop back into the body of the still, and be discharged with the effete residuum.

The system of channels shown in fig. 2 is so contrived as to bring the compound vapours which rise from the alembic A into intimate and extensive contact with metallic surfaces, immersed in a water-bath, and maintained at any desired temperature by a self-regulating thermostat or heat-governor. The neck of the alembic tapers upwards as shown at B, fig. 1; and at C, fig. 2, it enters the bottom or ingress vestibule of the rectifier C F. F is its top or egress vestibule, which communicates with the under one by parallel cases, or rectangular channels D, D, D, whose width is small compared with their length and height. These cases are open at top and bottom, where they are soldered or riveted into a general frame within the cavity, inclosed by the two covers F, C, which are secured round their edges E, E, E, with bolts and packing. Each case is occupied with a numerous series of shelves or trays, placed at small distances over each other, in a horizontal or slightly inclined position, of which a side view is given in fig. 3, and cross sections at D, D, D, fig. 2. Each shelf is turned up a little at the two edges and the one end, but sloped down at the other end, so that the liquor admitted at the top may be made to flow backwards and forwards in its descent through the system of shelves, as indicated by the spouts in fig. 3. The shelves of each case are framed together by two or more vertical metallic rods, which pass down through them, and are fixed to each shelf. On removing the cover, the sets of shelves may be readily lifted out of the cases to be cleaned; and are hence called moveable.

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The intervals I, I, I, fig. 2, between the two cases, are | the bath-vessel G, G; these intervals being considerably left free for the circulation of the water con ained in narrower than the cases. Fig. 4 represents in plan

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