For instance, no one will deny that swallows skim the surface of the earth on the approach of a storm. But it is simply because insects then swarm in the lower regions of the atmosphere. The swallows seek their prey where instinct teaches them that it is most abundant; not because a peculiar sympathy warns them of the coming storm. Swans, ducks, goslings, also, indicate hot weather by plunging oftener than usual, because the temperature being oppressive, they seek a fresher one under the water.
In the list of meteorological animals, leeches hold a prominent place. An English physician pretends that they are lively when the sky is clear and serene, and raise their heads above water to breathe the pure air. But if the sky be gloomy and clouded, they conceal themselves in the mud, and are evidently agitated at the approach of storms. The following are the observations of Dr. Vitet, in his “Treaty on Medical Leeches.”
“Close up a quantity of leeches in jars of equal size containing the same water, and expose them together to the open air. Never will you see identity of action. In one jar, they are at the surface, in another at the bottom, while in another they will be completely out of the water sticking to the cover. Again, you will see all the leeches of the same jar in all these different positions; some adhering by their tails from the borders of the jar, others balancing themselves with the most perfect regularity. It follows, therefore, that leeches are devoid of meteorological susceptibility.”
Had not Dr. Vitet made his experiments on so large a scale, a single leech, well-watched, would always have been said to announce changes of weather and temperature. In the case of the Rana Arboria, or tree-frog, which is sometimes confined in a glass jar to form a sort of living weather-glass, it may be noticed that, when two frogs of the same species are kept in the same glass, one is sure to be found at the top of the ladder and one at the bottom, proving how little such indications are to be depended upon.
To leeches is attributed another peculiarity, equally groundless; the faculty, namely, of ridding us of our corrupt blood, while they respect the pure; a fact disproved by daily experience.
According to a popular prejudice in many countries, snakes and vipers will creep down the throats of persons imprudent enough to sleep in the open fields with their mouths open; and strange things are related on this subject, especially in Germany.
About fifty years ago, the German newspapers announced that in Styria a young girl being asleep with her mouth open, a viper made its way into her throat. She was not aware of the fact; but a few days afterwards began to experience an insupportable irritation. On a subsequent day, the viper reappeared by the channel it had penetrated, hissing and raising itself on its tail as if overjoyed at its emancipation; and immediately afterwards, the girl vomited a quantity of viper’s eggs. This anecdote so charmed the French journalists, that they republished it in various directions, neither suspecting that they were renewing a fable of the Greeks, nor inquiring whether vipers were oviparous.
The adventures of the Styrian girl was nearly forgotten, when a French surgeon gave a fresh version of it in the following shape:
“In the month of June, 1806, a child of four years old having fallen asleep on the bank of the Canal de L’Ourcq with her mouth open, a snake crept in and passed into her stomach, where it remained for nineteen days; at the expiration of which, the child accidentally drank a glass of white wine, when forth came the snake in the presence of her whole family!” Witnesses were found to attest the fact; and the medical man who attended the child, asserted the reptile to have been eighteen inches long! Dr. Masson, surgeon to the civil Hospitals of Paris, made a report upon the subject to the Faculty of Medicine, attributing the attraction of the snake to the child having fed upon bread and milk, the predilection of those reptiles for that sustenance being well known.
Before we return to the above subject, we may as well inquire whether the predilection of snakes for milk be really true. The French peasants agree in this opinion with Pliny, Aldovrandus and Gesner. Yet all are wrong. Snakes are furnished with numerous little teeth at the extremity of their mouths, that their prey may not escape; so that if they sucked the cows as asserted by the peasants, their teeth must become inextricably entangled in the udder. The diminution of the milk in the dairies of the French provinces, is nevertheless often most conveniently ascribed to the interposition of snakes, innocent at least of this species of mischief.