From the _skins_ of perch a kind of isinglass is made which surpasses that made from any other fish. The Laplanders use it to stiffen their bows and make them durable. As this substance might be rendered of use for various purposes of domestic economy, it may not be altogether unimportant to detail the mode of its preparation. The skins are first dried, and afterwards softened in cold water to rid them of the scales. The Laplanders generally take four or five of the skins at a time, put them into a rein-deer's bladder, or wrap them in pieces of the bark of the birch-tree, so that they may not come in contact with the water. They place these in a pot of boiling water, putting on them a stone to keep them at the bottom of the pot; and in this situation they are boiled for an hour. When they have become soft and glutinous, they are taken out, and are then in a state fit for use. Perch may be bred and fattened in ponds; but care should be taken not to put them with other fish, as their voracity renders them extremely destructive to any that are weaker than themselves; or they should be accompanied by such only as are intended to furnish them with food. A pond may be stocked with perch by putting only the eggs or spawn into it; and if the situation and circumstances be favourable, the increase in a few years will be extremely great. These fish are so tenacious of life that instances have occurred of their being packed in wet straw and carried alive to a distance of fifty miles and upwards. 224. _The BASSE is a sea-fish somewhat resembling a perch, with a short and sharp spine on the posterior plate of the gill-cover, fourteen rays to the second dorsal fin, the back dusky tinged with blue, and the belly white._ _This fish sometimes attains the weight of twenty and even thirty pounds._ _It is found in the Mediterranean, the British Channel, the Northern Ocean, and the Baltic._ These voracious fish are caught during nearly all the year; but the months of August, September, and October, are considered most favourable for taking them. They not only approach the shores, but even ascend the rivers to great distances. Though their flesh is in general woolly and insipid, the Romans preferred them to many other kinds of fish, and sometimes paid high prices for them. Those which they chiefly esteemed were caught in the Tiber, betwixt the bridges of Rome. The eggs or _roes_ of the basse have sometimes been used in France and Italy to make what is called _Boutargue_ or _Botargo_. 225. _The COMMON MACKREL_ (Scomber scomber) _is known from other fish by having five small and distinct fins betwixt the dorsal fin and the tail._ _Its usual length is from a foot to eighteen inches, and its weight seldom exceeds two or three pounds._