When this species of fish was first discovered, marvelous accounts respecting them were transmitted to the Royal Society: it was even said that in the river Surinam, in the western province of Guiana, some existed twenty feet long. The present specimen is forty inches in length; and measures eighteen inches round the body; and his physiognomy justifies the description given by one of the early narrators, who remarked, that the Gymnotus “resembles one of our common eels, except that its head is flat, and its mouth wide, like that of a cat-fish, without teeth.” It is certainly ugly enough. On its first arrival in England, the proprietors offered Professor Faraday (to whom this country may possibly discover, within the next five hundred years, that it owes something) the privilege of experimenting upon him for scientific purposes, and the result of a great number of experiments, ingeniously devised, and executed with great nicety, clearly proved the identity between the electricity of the fish and the common electricity. The shock, the circuit, the spark, were distinctly obtained: the galvanometer was sensibly affected; chemical decompositions were obtained; an annealed steel needle became magnetic, and the direction of its polarity indicated a current from the anterior to the posterior parts of the fish, through the conductors used. The force with which the electric discharge is made is also very considerable, for this philosopher tells us we may conclude that a single medium discharge of the fish is at least equal to the electricity of a Leyden Battery of fifteen jars, containing three thousand five hundred square inches of glass, coated upon both sides, charged to its highest degree. But great as is the force of a single discharge, the Gymnotus will sometimes give a double, and even a triple shock, with scarcely any interval. Nor is this all. The instinctive action it has recourse to in order to augment the force of the shock, is very remarkable.
The professor one day dropped a live fish, five inches long, into the tub; upon which the Gymnotus turned round in such a manner as to form a coil inclosing the fish, the latter representing a diameter across it, and the fish was struck motionless, as if lightning had passed through the water. The Gymnotus then made a turn to look for his prey, which having found, he bolted it, and then went about seeking for more. A second smaller fish was then given him, which being hurt, showed little signs of life; and this he swallowed apparently without “shocking it.” We are informed by Dr. Williamson, in a paper he communicated some years ago to the Royal Society, that a fish already struck motionless gave signs of returning animation, which the Gymnotus observing, he instantly discharged another shock, which killed it. Another curious circumstance was observed by Professor Faraday—the Gymnotus appeared conscious of the difference of giving a shock to an animate and an inanimate body, and would not be provoked to discharge its powers upon the latter. When tormented by a glass rod, the creature in the first instance threw out a shock, but as if he perceived his mistake, he could not be stimulated afterward to repeat it, although the moment the professor touched him with his hands, he discharged shock after shock. He refused, in like manner, to gratify the curiosity of the philosophers, when they touched him with metallic conductors, which he permitted them to do with indifference. It is worthy of observation, that this is the only specimen of the Gymnotus Electricus ever brought over alive into this country. The great secret of preserving his life would appear to consist in keeping the water at an even temperature—summer and winter—of seventy-five degrees of Fahrenheit. After having been subjected to a great variety of experiments, the creature is now permitted to enjoy the remainder of its days in honorable peace, and the only occasion upon which he is now disturbed, is when it is found necessary to take him out of his shallow reservoir to have it cleaned, when he discharges angrily enough shock after shock, which the attendants describe to be very smart, even though he be held in several thick and well wetted cloths, for they do not at all relish the job.
The Gymnotus Electricus is not the only animal endowed with this very singular power; there are other fish, especially the Torpedo and Silurus, which are equally remarkable, and equally well known. The peculiar structure which enters into the formation of their electrical organs, was first examined by the eminent anatomist John Hunter, in the Torpedo; and, very recently, Rudolphi has described their structure with great exactness in the Gymnotus Electricus.
Without entering into minute details, the peculiarity of the organic apparatus of the Electrical Eel seems to consist in this, that it is composed of numerous laminæ or thin tendinous partitions, between which exists an infinite number of small cells filled with a thickish gelatinous fluid. These strata and cells are supplied with nerves of unusual size, and the intensity of the electrical power is presumed to [pg 600] depend on the amount of nervous energy accumulated in these cells, whence it can be voluntarily discharged, just as a muscle may be voluntarily contracted. Furthermore, there are, it would appear, good reasons to believe that nervous power (in whatever it may consist) and electricity are identical. The progress of science has already shown the identity between heat, electricity, and magnetism; that heat may be concentrated into electricity, and this electricity reconverted into heat; that electric force may be converted into magnetic force, and Professor Faraday himself discovered how, by reacting back again, the magnetic force can be reconverted into the electric force, and vice versâ; and should the identity between electricity and nervous power be as clearly established, one of the most important and interesting problems in physiology will be solved.
Every new discovery in science, and all improvements in industrial art, the principles of which are capable of being rendered in the least degree interesting, are in this Exhibition forthwith popularized, and become, as it were, public property. Every individual of the great public can at the very small cost of one shilling, claim his or her share in the property thus attractively collected, and a small amount of previous knowledge or natural intelligence will put the visitor in actual possession of treasures which previously “he wot not of,” in so amusing a manner that they will be beguiled rather than bored into his mind.
A Tuscan Vintage.
All Tuscany had been busy with the vintage. The vintage! Is there a word more rich to the untraveled Englishman in picturesque significance and poetical associations? All that the bright south has of glowing coloring, harmonious forms, teeming abundance, and Saturnian facility, mixed up in the imagination with certain vague visions of bright black eyes and bewitching ankles—all this, and more, goes to the making up of the Englishman's notion of the vintage. Alas! that it should be needful to dissipate such charming illusions. And yet it is well to warn those who cherish these couleur-de-rose imaginings, and who would fain shun a disagreeable désenchantement, that they will do wisely in continuing to receive their impressions of Italian ruralities from the presentations of our theatres, and the description of Mrs. Radcliffe. To those inquirers, however, of sterner mould, who would find truth, be it ever so disagreeable when found, it must be told that a Devonshire harvesting is twice as pretty, and a Kentish hop-picking thrice as pretty a scene as any “vindemia” that the vineyards of Italy can show. The vine, indeed, as grown in Italy—especially when the fruit is ripe, and the leaves begin to be tinted with crimson and yellow—is an exceedingly pretty object, rich in coloring, and elegant in its forms. Nothing but the most obsolete and backward agriculture, however, preserves these beauties. If good wine and not pretty crops be the object in view, the vine should be grown as in France—a low dwarf plant closely pruned, and raised only two or three feet from the ground; and than such a vineyard nothing can be more ugly. Classic Italy, however, still cultivates her vines as she did when the Georgics were written; “marries” them most becomingly and picturesquely to elms or mulberries, &c, and makes of them lovely festoons and very acrid wine. Again, it must be admitted that a yoke of huge dove-colored oxen, with their heavy unwieldy tumbril, is a more picturesque object than an English wagon and a team of horses. Occasionally, too, may be seen bearing not ungracefully a blushing burden of huge bunches, a figure, male or female, who might have sat for a model to Leopold Robert. But despite all this, the process of gathering the vintage is any thing but a pleasing sight. In one of the heavy tumbrils I have mentioned, are placed some twelve or fifteen large pails, some three feet deep, and a foot or so in diameter. Into these are thrown pell-mell the bunches of fruit, ripe and unripe, clean and dirty, stalks and all, white and red indiscriminately. The cart thus laden, the fifteen pails of unsightly, dirty-looking slush, are driven to the “fattoria,” there to be emptied into vats, which appear, both to nose and eye, never to have been cleansed since they were made. In performing this operation much is of course spilt over the men employed, over the cart, over the ground; and nothing can look less agreeable than the effect thus produced. Sometimes one large tub occupies the whole tumbril, the contents of which, on reaching the “fattoria,” have to be ladled out with buckets. Often the contents of the vat, trodden in one place—a most unsightly process—have to be transported in huge barrels, like water-carts, to another place to undergo fermentation. And then the thick muddy stream, laden with filth and impurities of all sorts, which is seen when these barrels discharge their cargo, is as little calculated to give one a pleasing idea of the “ruby wine” which is to be the result of all this filthy squash, as can well be imagined. Add to this an exceedingly unpleasant smell in and about all the buildings in which any part of the wine-making process takes place, and the constant recurrence of rotting heaps of the refuse matter of the pressed grape under every wall and hedge in the neighborhood of each “fattoria”—and the notions connected with the so be-poetized vintage, will be easily understood to be none of the pleasantest in the minds of those acquainted with its sights and smells.—Trollope's Impressions of a Wanderer.