পাতা:পদার্থবিদ্যাসার.djvu/১৩৭

126 dried. There are several ways of killing these insects. Some put them in a basket, and dip them in boiling water, and afterwards expose them to the sun to dry; others put them on heated plates of iron, &c. and so kill and prepare them for use at one operation. After they have been dried, ihey may be kept for a great length of time without injury. . Pup. What is the use uiade of ihe lac ? Tut. It is used in manufacturing a great variety of things. Of shell lac the natives of this country make ornamental rings to decorate the arms of females. They also form it into beads, necklaces, and other ornaments. It was formerly used in medicine, but it is now principally confined to the making of sealing wax, and to japanning, painting, and dyeing. Pup. Are spiders of any use Tut. Our aversion to spiders arises from their ejecting a poisonous matter, with which they kitl their enemies. But I believe the quantity they can eject, though fatal to insects, would not produce on us any great injury. Spiders, however disagreeable to us, are not without their use: they catch and destroy many flies: the webs which they spread over the trees in summer, in some degree preserve the fruit. And they may be more useful in our houses than we are aware of. They may inliale some noxious qualities of the air, which might otherwise become prejudicial io us. The webs which spiders forin, particularly in gardens, are exceedingly curious. Pop. How do the field spiders carry their first thread from tree to tree, and from house to house, as we often see in the summer ? - Tut. Some have thought that the spider must fly to do this; but she transports herself in this