it should assume the appearance of a well curled wig, (we have no better phrase,) having broad flaky curls, it denotes unsoundness. The aroma should now be very perceptible.

3. The curly head should then rise to a light yeasty or rocky head, little more than, perhaps, from two to three feet high, of a fine brownish-white colour if sound. If unsound, it assumes in some parts, an ugly bluish-white appearance, which often extends over the tun. This almost invariably happens where there is any galvanic action from chains of pipes, or a mixture of metals; and cannot be cured or prevented, but by doing away with the cause: that is, by insulating the tuns.

4. After a time, the light yeasty head should drop a little, perhaps 3 or 4 inches. This we call the 4th change. The aroma should now be very vinous and pungent.

5. The light yeasty head which had dropped, should now rise to what we call a close yeasty head, having the appearance of yeast all over, with many little air bubbles on the top, not, however, larger than a nut or a walnut; these constantly breaking, and others supplying their place. If the fermentation has been healthy throughout, the close yeasty head will continue rising, and puffing out gas from the air bells, until the beer is thought ready for cleansing. This will take place earlier or later, according to the quality of the beer and the public

taste.

Should all these changes, as before stated, take place regularly, and be accompanied through the process by a sound healthy aroma, (generally termed "stomach,") we may rest assured that all is right, and that the beer, if afterwards properly treated in storing, will turn out sound and good.

Sometimes, however, instead of these five changes, not more than three are perceptible, all of them fretful and unhealthy. (These appearances will be more fully treated of, when we describe Irregular Fermentations.) In that case, we know that the worts must have been tainted somewhere ; the cause of which must be traced and corrected before any successful results can be expected. In most of the brewhouses which we have visited, we have invariably found, that the want of uniformity in fermentation did not arise from the uncertainty, as it is called, of the process, but from one or more of the causes before mentioned. We think, therefore, we are warranted in stating, that fermentations, when conducted on strictly chemical principles, may be carried on with nearly as great uniformity as any, other chemical process.

Of Irregular Fermentation.

After what has been said about sound regular fermentations, it may by some be thought unnecessary to describe those which are irregular. There are many brewers, however, as before asserted,

who, from causes already mentioned, have never had it in their power to see a thoroughly regular and good fermentation. Such are apt to think that all is right, although the contrary may be the case; we, therefore, think it better to describe some kinds which have come under our own observation, and shall commence with

Inert Fermentation.

This is perhaps the most dangerous, because it is the most deceitful. This fermentation, to inexperienced, and even to many experienced brewers, has every appearance of proceeding remarkably well, and they of course think that all is right. The beer, however, will always taste mawkish and heavy, and without vinosity, although the attenuation may have been carried to its proper extent. There can be no doubt of its proceeding from some of the causes of unsoundness already mentioned. It first makes its appearance in the second change, viz. the curling top, which, instead of assuming the fine cauliflower appearance, diverges into long flaky curls hanging downwards; as soon as the "stomach" or smell of the gas begins to rise, a mawkish want of pungency and vinosity is discoverable by those who are acquainted with the proper odour.

The light yeasty head, instead of rising with a rocky appearance, is smooth all over; it, however, often drops regularly, as in a healthy fermentation.

The proper close, yeasty head never rises, instead of which, if it does again rise, we have the same frothy appearance as before, smooth all over, with no appearance of air-bells as in a healthy process. The "stomach" also retains the same mawkish want of pungency and vinosity.

We have been thus minute in describing the progress of the above fermentation, because it is the most insidious and dangerous, as also the most common and least known or understood. How often do we hear of mawkishness in the taste which can

not be accounted for. We may rest assured that in nine instances out of ten, it proceeds from the inert fermentation, and not from want of boiling, to which it is generally ascribed.

Before the remedy can be known, the cause must be traced; every experienced brewer will then know how to proceed.

The Boiling Fermentation.

This, to look at, is the most formidable of the irregular forms of the process, and proceeds also from unsoundness in the worts, or occasionally from bad yeast; for which also there is no certain remedy but tracing and removing the cause. It commences, like others, with a creamy top, but the curl rises very light and faint, and in patches over the tun. The light yeasty head has an ugly, bluishwhite appearance in some parts of the tun, while in

others it has a fretful blistery appearance, and only just covering the beer: this is accompanied with little or no attenuation. The stomach, although sometimes pungent, is neither healthy nor vinous. When the light yeasty head disappears, no other head rises, and the fermentation very soon assumes the appearance of a boiling cauldron.

In the early part of our practice we have had occasion to see a good many boiling fermentations which we could not then account for. Since that time, however, we have been enabled to trace the causes, and invariably to remove them.

Of Close Fermentation.

Many think that fermentation goes on better when the gyle-tuns are accurately closed, so as to prevent contact with the atmosphere. In as far as regards the atmosphere, this opinion is correct; but when fermentation goes on vigorously, there can be no connection with the atmosphere,-the great production of carbonic acid gas excluding it. Carbonic acid gas is heavier than atmospheric air, in the proportion of 1527 to 1000, and while it floats on the surface of the beer, and at the same time is produced in such quantities as to be constantly making its escape, atmospheric air cannot possibly interfere.

About the year 1824, Mr. Gray, of Westham, on Madame Gervas's principle, attempted to intro

H