when the mashing begins. This sometimes is performed by long oars, poles, or iron rakes, mingling the fluid with the farinaceous matter, until they are completely incorporated: but the scale on which the London breweries are conducted has long rendered obsolete all these manipular contrivances, and introduced regular mashing machines. A strong iron screw fixed in the centre of the mash tun is furnished with radii (two or more), also of iron, and armed with vertical iron spikes or teeth, a few inches asunder, in the inanner of a double comb. Horses, or a steam-engine, furnish the moving power. The iron radii, which at first rest on the false bottom, are made slowly to revolve upon the central screw, in consequence of which, in proportion as they revolve, they also ascend through the contents of the tun to the surface; then, inverting the circular method, they descend again in the course of a few revolutions to the bottom, mingling in their alternate motions, the grist and the water. After mashing, the tun is generally covered to prevent the escape of heat, and the whole remains untouched, until the insoluble parts separate from the liquor: the drawingoff-pipe is then opened, and the clear liquor runs away.

We need not occupy this part of our work with a repetition of the cautions given on the subject of mashing in the article already often adverted to, on ALE: but only remark here, that this liquor, or wort, as it is now called, of the first mashing, being always by far the richest in saccharine will require and reward the greatest care in obtaining it. To do justice to the malt, a second and even a third mashing is taken; and in some breweries the water employed for the last is simply made to penetrate through the grist by means of a broad shute, of a triangular form, narrow under the cock of the copper, and spreading from ten to fifteen feet wide over the mash tun edge, so as to throw the water over the mash lightly. Thus the mashed grist is very little disturbed, and the water applied drives before it the infusion of the second mash, contained in the grist, through the mash, until, by occupying its space, it extracts a greater strength from the malt, than the ordinary mode of mashing would. The gravity of the worts must regulate, of course, the quantity of liquor employed (for technically all water is liquor in the brewhouse). so as to retain the average density of the two or three worts taken together, according to the length or quantity of beer intended to be brewed. Mashing thus conducted by machinery, generally is completed in about from thirty to forty-five minutes. The temperature and gravities in respectable establishments are carefully noted at stated times in the brewing-book. Cloudy worts indicate a too high temperature. If the heat of the water is not above 185°, there is nothing to fear; in practice, however, it seldom exceeds 160° or 170°. At 198° most worts are cloudy. See ALE. In regard to porter brewing, it may be observed, that the higher the color of the malt, the less is its tendency to set, because high dried malt contains a less portion of undecomposed starch than pale or amoer malt; of course we may mash with water of a higher tem

perature. Though it has often been discussed, it seems practically of little consequence, whether rain, river, or spring water, be employed in the larger brewing operations. Mr. Accum analysed that used by Messrs. Truman and Co. and found it to possess all the characters of pump water; the reader, as he says, need not be reminded that the beer brewed at that establishment is inferior to none.

For heating the water and boiling the wort, large establishments use a copper crowned with a hemispherical dome; surrounded by a pan which will contain a succeeding wort, or the water for a succeeding mash. The liquor is generally boiled by steam in the following way :From the centre of the dome rises a perpendi cular pipe, and from the upper extremity of this pipe four inclined pipes descend, the lower extremities of which terminate near the bottom of the pan, and consequently in the water or wort contained therein. By this contrivance, the steam which rises from the copper must bubble up through the fluid in the pan, and speedily heat it. The advantages of this contrivance are, that, the instant the copper is emptied, a fresh supply of fluid can be let in to cover the bottom of it, in order to prevent the intense heat of the fire injuring the vessel; while the successive fluids are heated by one fire.

As to hopping, we need only here observe, that the quantity of hops is regulated by the strength of the wort, and the time the beer is intended to keep. Generally from 1 to 13 lb. or even 2lbs. of hops are boiled with every bushel of malt; but, for strong ale or porter, the quantity is sometimes higher. After the first boiling with hops, the liquor is let off, and the wort is conveyed into the jack or hop-back, furnished generally with a cast-iron floor full of holes, so as to drain the wort from the hops. Then those left in the jack-back are filled, by men, into tubs, which are drawn up by a tackle worked by the engine, and again boiled in the copper with the second and third worts. Sometimes an axis passes perpendicularly through the copper, furnished at the end with horizontal arms, from which chains are suspended in loops, and which stir up the hops at the bottom of the copper when the axis is made to revolve. This apparatus is called a rowser. The following table, extracted from Mr. Richardson's work on the use of the Saccharometer, exhibits the quantity of wort imbibed in boiling by different quantities of hops :

Cooling, of course, is a process of great impertance, and must be conducted on a scale proportionate to our other operations. Nothing yet has been found to supersede the use of large shallow wooden troughs or floors, edged with a wooden ledge, and water-tight; the most exposed situation that the premises will afford being chosen, so that a free current of air may at all seasons be brought over them. To perform it expeditiously, so that the taint of foxing may not ensue in this process, the wort should only be laid at such a depth in the coolers, as will allow it to cool in about seven or eight hours to sixty degrees, which, generally speaking, is about the average temperature for pitching or setting to work. To effect this, in summer, the wort should certainly not be laid at a greater depth than one, two, or three inches; in winter, it may be as deep as five inches. The evaporation that results, on the liquor being conveyed into the coolers, is a great object of the scientific brewer's attention.

On the still more important point of fermentation, we have little to add to our previous reinarks. In the brewing of porter, which is generally intended to be full bodied (hard), the fermentation must be suffered to proceed slowly, as far as it is consistent with the richness of the wort; if the beer is intended to be rather brisk, the fermentation is the sooner stopped. Ordinarily ale and porter, of which the specific gravity of the wort amounts to 17-25 lbs. per barrel, or 18 lbs. per barrel, requires the fermenting process to be stopped when the specific gravity is reduced to 7, 8, or 9 lbs. per barrel: but scarcely any general rules can here be given. The diminution of the specific gravity is, in some breweries, suffered to proceed to a much greater extent than in others: observation must be directed to the head of the yeast. When the fermentation is brisk, it soon begins to turn of a compact brown color, and becomes rapidly more colored and dense, so that it would fall back into the beer; at this period the fermentation is nearly finished.

'During the process of fermentation,' says an able chemist, a large quantity of carbonic acid gas is disengaged; the noxious effect of this gas has been long known, it produces suffocation when taken in the lungs. Being heavier than the air of the atmosphere, it floats on the surface of the fermenting fluid, and occupies, when it overflows the vessel, the lowest parts of the place in which fermentation is carried on. This gas appears to be the only product of fermentation to which we are indebted for all the remarkable changes by which the sweet or saccharine matter of the wort is converted into a vinous fluid. The superfluous carbon of the sweet substance, and a portion of the oxygen, combine to create it, while the balance of principles which remain, becomes capable of generating the ardent spirit, or alcohol. It is, therefore, a necessary consequence of the process of fermentation, but it is not equally necessary that it should be disengaged and separated from the beer, for a large portion of it remains combined with it. It holds a portion of alcohol, in a state either of mixture or combination, of which the true chemical nature has not been well ascertained. This is a question of some difficulty, as well as of importance in a

chemical point of view, but as yet no experiments have been suggested capable of setting it at rest.

Dr. Thomson complains of the difficulty of ascertaining with accuracy the strength of the worts in the London brewery. In some breweries, as in that of Messrs. Barclay and Perkins, there are three separate mash-tuns. In others, the custom is to mash one kind of malt the first day, another the second,and a third kind the third day. The first day's wort is put into the fermenting vessel, and mixed with yeast; and the other two worts are added to it as they are formed successively. Their strength, therefore, could only be ascertained by knowing the quantity of wort from each malt, and its specific gravity when let into the fermenting vesse! After, in this way, examining the porter wort in the principal breweries in London, he says the average specific gravity of brown-stout wort is 10624. The wort of the best common porter is of the specific gravity 1.0535; that of the worst or weakest is as low as 10374. The average specific gravity deduced from twenty brewings, was 1.0500. Such wort contains about 46.4 lbs. per barrel of saccharine matter. Judging from the taste of some of the worts, quassia, says Dr. T. seems to be employed in considerable quantity by some of the brewers, and much more sparingly, if at all, by others. The fermentation of porter is carried on with considerable rapidity, so that it is over in two or three days. The specific gravity of the porter is usually brought down to 1'013 or 1017. That of the best brown-stout, after standing some months in the bottle, is 1.0106.

We know of nothing that distinguishes the mode of cleansing porter from that of cleansing ale, except, perhaps, better mechanical contr vances, according to the size of the breweries. In some breweries, the method of cleansing beer by means of large barrels or rounds, is practised throughout the year. Sometimes it is stored in casks, which are bunged up and removed into the storehouse, but daily examined, and occasionally allowed a little vent, especially in warm weather; or the beer is pumped into a cistern, and from thence into the store-vats, which are from eightteen to forty feet in diameter, and from eightteen to twenty feet high; they will frequently hold from 5,000 to 6,000 barrels. Large arched vaults, built of stone, and lined with stucco, have been, at some establishments, adopted for storing the beer. These contribute greatly to the amelioration of the beer by age, in consequence of the uniform temperature which fluids in such masses preserve. These vats are always placed in the coolest part of the establishment; are made air-tight, and furnished with safety valves. excellent piping, cocks, &c.

For the use of the saccharometer in brewing. See SACCHAROMETER.

For finings in filling up the casks. See Air and FININGS.

By law, every barrel of beer or ale, brewed by the public brewers in Great Britain, whether within or without the bills of mortality, is to contain thirty-six gallons, according to the standard ale quart kept in the Exchequer; 43 Geo. III. c. 69.

But nothing herein is to extend to alter the quantity to be returned, as and for a barrel o beer or ale brewed by any victualler or retailer, or any person other than a common brewer, wno