The ancient mode of collecting ladanum, if the accounts which have been stated respecting it may be credited, was not a little curious. Goats, which delight in grazing upon the leaves and young branches of the shrubs that produce it, were turned loose into the plantation, and the resin that adhered to the long hair of their beards and thighs was afterwards detached by combing them. The present method is different, and is a laborious and troublesome employment. Tournefort informs us that he saw seven or eight country fellows, in their shirts and drawers, and in the hottest part of the day, drawing over the shrubs a kind of whip, or rake, with numerous long straps or thongs of leather. From these they collected the resin, by scraping it off with a kind of knife; after which it was made into cakes of different sizes for sale. As loose sand generally adheres, in considerable quantity, to the viscous leaves of the shrub, it is not unusual for dealers in this drug to adulterate it with sand. We import ladanum principally from the Levant and the Persian Gulf; and it comes to us in cakes or masses of different size, dark colour, and about the consistence of soft plaster; and also in rolls, lighter-coloured and much harder, which are twisted up so as somewhat to resemble the rolls of wax tapers. The smell of ladanum is strong, but not disagreeable; and its taste is warm, aromatic, and somewhat unpleasant. This drug was formerly much used as an internal medicine; but it is now employed only externally, as an ingredient in plasters. 177. _The TULIP-TREE_ (Liriodendron tulipifera) _is an American production which yields a very beautiful and valuable kind of wood._ _It sometimes grows to the height of sixty or seventy feet; and has lobed leaves, and tulip-shaped flowers._ While young, the _wood_ of the tulip-tree is white; but at an advanced age, it assumes a fine yellow colour, or a streaked appearance of different shades of red. This wood is equally useful in ornamental furniture, and as a timber for building. It is occasionally employed in the construction of light vessels; and the trunks of tulip-trees are frequently hollowed by the Indians into canoes. When they have been grown in a favourable soil and climate, one of them is sufficiently large to be made into a canoe capable of containing several people. On account of its quick growth and easy culture, this noble tree well deserves the attention of planters in our own country. ---- CLASS XIV.--DIDYNAMIA. ---- GYMNOSPERMIA. 178. _LAVENDER is a well-known perennial garden plant_ (Lavandula spica) _which grows wild in the south of Europe, and the flowers of which yield a grateful perfume._