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come too near these delicate bodies, which can hard. Hy be touched without hurting them. All places are not equally fit for them; they fhuuld neither be tco dry, nor too moist, nor subject to be intested by such infects as they have an antipathy at, or which are restless and turbulent. · Of all exposures the least fa. vourable are those of the north and fouth. The winds from thefe two quarters are exceedingly perni. cious to them, the one by its coldness, the other by its humidity; for which reason, it is neceffary, that the place be so disposed, as that its temperature may be regulated, by shutting the windows on one side, and keeping them open on the other, according as the wind shall blow from the north or south. When the weather is moist, it is proper to keep the place quite close; but when it lighiens, that is not fufficient; the filk worms must be covered up, otherwise they contract a difease, which fome curious persons have thought proper to term jaundice. They do indeed acquire a yellow colour, lose their appetite, and die insensibly. Those that die, should be separated from the living, for fear of communicating infection to shem,
- C H A P. I.
How INSECTS HURT THE PRODUCE OF THE EARTH,
· Not only do insects pillage and ravage the fields,
but they attack man in his domestic econony, and do him infinite mischief. Nothing can be protected against their ordure; we fee, with regret, our most precious furniture tarnished and infe&ed by flies. These restless insects enter our libraries, nestle in our cabinets, pass from one apartment to another, and leave every where behind them, the most conspicuous marks of their having been present. There is not a man, from the king to the poorest of his subjects, who can defend himself against their attacks.
Husbandmen perhaps are the most to be pitied. How often do they not find themselves disappointed of a plentiful crop by the depredations of locusts! These voracious animals often leave diftant countries, Traverse oceans, pour in myriads upon sown fields, and deprive them in a few hours of every appearance
of of verdure. Are not caterpillars often as noxious to us? I know not a more cruel scourge for gardens than they are. They eat into flowers, they gnaw the roots, and so destroy the plants they touch, that we are obliged to throw them away. Some do not wait till a plant is able to furnish them food for weeks, they devour it the moment it appears. Others on the contrary wait till the feed is produced ; they then devour it so greedily, that nothing is left but the empty skin to the owner. Weevils are not behind hand with these ; they pierce the ripe grain, eat the pulp, and thus rob our granaries of that food which is of the greatest importance to the human race.
· But it is not on herbaceous plants alone, that infeets bring ruin; their attacks are not less disastrous to fruit trees. If they deposit their eggs in autumn, the young caterpillars are hatched in the Spring when the trees are only beginning to shoot forth, and they commit such ravages on the buds and foliage, that wherever they are found in numbers, the fruits of the year entirely fail. The small Curculios, some beetles and several sorts of caterpillars conspire in producing this devastation, and sometimes reduce the trees to the same state they were in during winter. This is not all, for there are some sorts of golden coloured beetles which produce two forts of larvæ, red and white. These larvæ penetrate the bark, and suck the juice till the tree becomes completely dried up. There are also some small beetles which, not content with eating the bark, attack the wood, and contrive to desolate whole forests. This accident has but too often happened with woods planted with pines. The wood of Schwartzenburg experienced this to such a degree in the year 1736, as cost its proprietor many thousand crowns. I ihall content myself with this one example; those, which I could adduce of many other forts
which destroy wood are too common not to be known by every one,
OF THE EVILS WHICH INSECTS CAUSE TO MAN.
We have spoken of the ravages which infects make both in the country and in towns ; let us now take a view of ihe mischiefs they occasion to man himself personally. Some disturb his fleep, others oblige him to pass whole nights without sleeping at all. In. deed, what does he not sometimes suffer from the restless flea, and the loathsome bug? How can he take rest when unhappy enough to be exposed to the fanguinary insults of such tormentors ? But were he free from these, the gnats do not cease to persecute him. Their inceslant buzzing disquiets him, and whether asleep or awake, while in darkness he is equally a prey to those stings which he dreads but which he cannot prevent. In the East Indies the inhabitants are exceedingly tormented by those insects which the Portuguese call Mosquitoes. These dangerous animals dart upon those whom they sura prize asleep, and in such prodigious numbers that it is no easy matter to refist them. When one is stung in the face, or in any other part of the body, there enfues a considerable tumour, accompanied with itch. ing and intolerable pain.
There is another kind of insects which are hurtful to man by mere touch. Such is the Scolopendra ma. rina, which causes a pricking in the skin, and a heac similar to that which one feels after having touched the common nettle. Among those which render themselves formidable by their prickles, some have the hair fo acute that they wound almost imperceptibly, occasioning an inflammation which quickly brings on fever ; others, as the hornet and bee, strike with their sting, and though the wounded part does not bleed, it does not suffer the less, and a fensible fwelling succeeds. Besides these different insects there are others which like the gad fly have stings so sharp and strong that they can pierce the skin through gloves and stockings; others are remarkable by their bite like spiders; and fome attach themfelves to our bodies and suck the blood. The East Indies swarm with leeches, to which the Dutch have given the name of Snygers. They lurk in general among the grass, when the dew has moistened the ground, and as the country, which is intersected by rivers, torrents and swamps, obliges travellers to walk for the most part with naked feet, it happens that these animals cling to the legs and gorge themselves fo with blood, that they fall off spontaneously. There are some fo greedy that they thrust their head into the skin as far as the neck, and the only method of making them quit their hold, is by surrounding them with mciitened gun powder, when they will come away of themselves in about a quarter of an hour or thereabouts. If a person ignorant of this expedient should think of employing force to detach these anj. mals suddenly, he would pay dearly for his impru. dence. Not only would he experience violent pain, but a part would remain in the skin, engender an abíceis, and corrode the flesh to a great depth. I appeal for the truth of this to the fad experience of many persons who for several years have been subject to
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