“Some wines force out the corks from their bottles and are covered with foam on being poured into glasses. These are foamy wines, and to produce them the bottling must be done before fermentation is finished. The carbonic acid gas then continues to form, but as it finds no way of escape since the [[227]]bottle is tightly corked, it dissolves in the liquid and accumulates there, though all the while endeavoring to free itself; and that is what makes the cork pop with a sharp report when the string that holds it down is cut; that is what causes the wine to rush foaming out of the bottle; and, finally, that is what gives the bead to a glass of wine and makes a slight crackling sound as the bubbles burst on the surface.
“Foamy wine has a pungent but agreeable taste owing to the carbonic acid it contains. We drink, dispersed through the liquid, the same gas as would kill us if freely inhaled; but it has no terrors except when thus inhaled. Mixed with our drinks, it imparts to them a slightly tart flavor, harmless and even salubrious, since it aids digestion. There is carbonic acid gas in nearly all water that we drink, and it is in fact by reason of this gas that water is able to hold in solution the small proportion of stony matter that contributes toward the formation of our bones. It is to this gas, finally, that effervescent lemonade, cider, beer, and Seltzer water owe their pungency and their foam.” [[228]]
CHAPTER XLV
THE STAG-BEETLE
“One of the joys of your time of life, I am sure,” resumed Uncle Paul, as he and his hearers seated themselves in the shade of an old oak tree amid the humming and whirring of insect life all about them, “is the study of the little creatures of field and farm and forest, so interesting in their mode of life, so varied in their forms and colors. You chase the splendid butterfly from flower to flower, you take up the cockchafer and put it on a bed of fresh leaves, with a straw you drive the cricket from its hole. The insect that amuses you can also instruct you. In our modest studies let us now have a little talk on this subject.
“What is this tiny creature with the stout coat-of-mail of chestnut color? Its large head, showing parallel folds that might have been carved by a sculptor’s hand, is armed with two branching nippers which open like a pair of tongs and then close, mangling between their teeth the finger they have seized. Woe to the giddy-pate that lets himself be caught by them! The trap closes tighter and tighter and never lets go.
“But, vigorous as are its mandibles, the insect is not one to be afraid of, provided only you look [[229]]out for those nippers. For all its threatening aspect, it is at bottom a peaceful creature. Catch it by one leg and it will fly round and round like the June-bug. It is called the stag-beetle, a name that explains itself, for it has branching mandibles resembling a stag’s horns, and it belongs to the family of beetles. Put the two words together and you have ‘stag-beetle.’
“The singular creature has not always been as we see it to-day. In its youth, not later than last year, it had neither its present mandibles nor its six legs nor its chestnut-colored coat-of-mail. In fact, its form had nothing in common with what we now behold. Then it was a big, fat worm, with fine white skin, crawling on legs so small and feeble as hardly to deserve mention.
