« ПредыдущаяПродолжить »
discipline; "the virtuous thoughts of the day lay up good treasures for the night." But we are now touching on the land of Dream, and must pause ere we venture to explore its mysteries. We shall return to it anon; and then, as we draw aside the curtain, it will be made manifest that “Our life is twofold-Sleep hath its own World."
The Chemistry of a Pint of Beer.
Ta late meeting of a very useful little Metropolitan Mechanics' Institution, which it is not necessary to our present purpose to name, a discourse on the subject above mentioned was delivered by Mr. James Saunders, practical plumber and glazier, amateur chemist and natural philosopher.
Mr. Saunders commenced his lecture by observing, that much ado was being made just now about the Papal Aggression. This remark might appear foreign to his subject, but, in fact, led up to it; for the Pope of Rome had occasioned a fermentation in this country; and without fermentation there could be no such thing as that which he was about to have the pleasure of discussing-a pint of beer. He should say no more on the fermentation caused by the Pope, except that he hoped it would be followed by the usual results of that process as observed in brewing—a sinking of the dregs; a going off of flighty volatile gas; and strength communicated to the good stuff in the barrel.
"For many of the observations I'm about to make, Ladies and Gentlemen," continued Mr. Saunders, "I shall have to apply to my notes; for which I'm beholden to our worthy Doctor, who is now amongst us; and I hope he'll
excuse me for any mistakes I may make in pronouncing some of his words.
"In the first place, what is a pint of beer? 'Twopence,' says some of you,' and a deal too much! That's not the question. There's a great many beers. There's porter, there's heavy, or brown stout, and there's strong beer, and ales of ever so many sorts, and, then, there's swipes. Which is it to be? Well; please to take beer as meaning malt liquor in general—a fermented drink made out of malt and hops. In a chemical sense, it don't much matter what tap it is. Here I may be asked, perhaps, what chemistry has to do with beer? Every thing. Brewing's a regular chemical operation. Of course, I haven't time to go into the whole art and mystery of brewing. I sha'nt attempt more than to give you some sort of notion of the science of that beautiful process. Well; now then we'll begin by inquiring what beer is made of?
"The answer most of you would make to this question, I take it, would be, Malt, hops, and water.' Some would add, perhaps, and a little isinglass, for finings.' That's what it ought to be made of, to be sure. But there's more
things in ale and beer, ladies and gentlemen, than is dreamt of in your society-However, let us take beer as brewed simply of water, malt, and hops-what you may call Utopian Entire; though, mind, 'tis in the power of all of us to realize this salubrious and agreeable beverage, if so be as we've got the means, and will take the trouble ourselves, for to brew the same.
"We'll say, then, that beer is made of malt, hops, and water. Very good. But now comes another query. What is water, and hops, and malt made of?
66 'First, what is water made of? Ah!-there was a time when heads, with big wigs on 'em, would have been
shook at me for asking that question. I should have been thought mad-perhaps worse. But we live in better times, thanks be. You've been told afore, most of you, no doubt, that water, when quite neat, which you can't get, except by distilling of it, is made of oxygen and hydrogen, which are two sorts of gas; that is, when separated one from the other, as can be done by galvanism and other ways and means, and collected apart. Rain-water, fresh from the clouds, contains a little fixed air besides; the same air that comes out of soda-water and ginger beer: what they call carbonic acid; namely, carbon, the same thing as charcoal, turned into gas by being combined, as the word is, with oxygen. What river-water contains depends a good deal on what goes into the river; the idea whereof may be left to imagination, with the hope it won't disorder the stomach. Same with well-water drawn from nigh sewers and churchyards. Besides these things, which have no business in water, both river and well-water contain various salts, more or less. There's carbonate of lime in 'em, carbonate of magnesia, carbonate of potash, now and then sulphate of iron, and so on, according to the soil they run through, or spring out of. Sulphate and carbonate of lime (in other words, plaster of Paris and chalk) cause water to be, what is called, hard; which is bad and wasteful for making tea; but whether it is the worse or no for brewing beer is a dispute among brewers; and who's to decide when brewers disagree? It stands to reason that the quality of the water must have more or less effect upon the quality of beer; so, no doubt, the difference between the beers of different places depends, for one thing, on the kind of water they are brewed from.
"Next, as to the hops. The hop-flower, belonging to the vegetable creation, is made of carbon, oxygen, and hy
drogen. Besides, there's a bitter extract in it, and likewise a drowsifying sort of principle, something like what there is in opium, called Humulin.
"Now for the malt. What is malt? Not many of you, I suppose, are such cockneys as not to know that malt is barley, steeped in water, laid out on a floor, let be there till it is just about to sprout, and then dried on a kiln, at a heat high or low, according to the color you want it to be; pale or amber, or brown. Here begin the chemical manoeuvres required to produce a pint of beer. Malting is a process of chemistry that goes on in each grain of barley inside of the husk. What are the chemical ingredients of barley? Carbon, oxygen, hydrogen, and a little nitrogen. Malt has the same. But the difference between barley and malt is, that the carbon, oxygen, and hydrogen in the barley are in the shape of starch; whereas, in the malt they are in the state of sugar. In going to sprout the barley gets sweet, and the starch in it changes into sugar. Both sugar and starch have the same proportions of carbon, oxygen, and hydrogen; twelve of carbon, ten of oxygen, and ten of hydrogen in each —that is to say, water and charcoal. The difference between starch and sugar is thought to depend on the carbon, oxygen, and hydrogen in the one, being ranged together in a different way from what they are in the other. The ultimate particles' of carbon, oxygen and hydrogen, being 'ground together,' as the phrase is, in one way, form starch, and in another, sugar. So with gum, and several other things, that have the same elements-as chemists say— and in the same proportions as sugar, but differ from it in look, and taste, and feel, and some other properties. It seems as though, whilst they are the same in point of chemical ingredients, they differ as to chemical texture. they are the same things in different forms. All these