223. The plants, esreially if weak or not healthy, are subject to the attack of a small species of coccus (C. hes peridum, Lin.) commonly called the pine-bug. The in sects adhere closely to the leaves, often near the base, and seem almost inanimate. Mr Miller recommends turning the plants out of the pots, and cleaning the roots ; then keeping them immersed for four-and-twenty hours in wa te• in which tobacco stalks have been infused : the bugs are then to be rubbed of with a sponge, and the plants, after being washed in clean water and dripped. are to be repotted. Mr Muirhead, a gardener in the north of Scot land, has described a similar mode, (Scottish Hort. Mem. vol. i. p. 2090 only in place of tobacco juice he directs flowers of sulphur to be mixed with the water. With a bit of bass-mat fixed on a small stick and dipt in water, he displaces as many of the insects as he can see. He then immerses the plants in a tub of water, containing about I lb. of flowers of sulphur to each garden-pot full. They remain covered with the water for twenty-four hours, as desired by Miller. They are then laid with their tops downwards, to dry, and are repotted in the usual manner. What share of the cure, in either of these ways, may be due to the sulphur or to the tobacco liquor, does not clearly appear ; the rubbing off or loosening the insects is evidently important ; and it is not unlikely that immersion, in simple water, so long continued, may alone be sufficient to destroy them. Indeed, the experience of one of the best practical gardeners in Scotland (Mr Hay) leads him to conclude, that even moderate moisture is destructive to these insects. During many years, he regularly water ed his pine-plants over head with the squirt, during the summer months : this was done only in the evening ; it never injured the plants; and the hug never appeared upon them.
The Orangery.
224. This is merely a green-house, and indeed is gene rally employed in part for protecting ornamental plants and shrubs. In a few places the orange trees are planted in the border soil, in the manner of shrubs in a conserva tory. The genus citrus includes not only the orange, but the shaddock, lemon, citron, and lime : it belongs to the class and order Polyadelphia Polyandria, and natui al order Aurantix of Jussicu. In writ m countries the trees rise to the height of perhaps fifty feet ; 'me they seldom exceed the size of shrubs. The species may readily be distin guished by the petiole or leaf-stalk : in the orange and the shaddoek, this is winged ; in the lemon, citron and lime, which are considered as vat ieties belonging to one species, it is naked. The orange and shaddock fruits are almost spherical, and of the yellowish- red colour known by the name of orange ; the lime is spherical, but of a pale yel low ; the lemon is oblong, with a nipple-like protuberance at the end ; the citron is oblong, and distinguished by hav ing a very thick rind.
225. Of the Orange (Cyrus aurantiuni, Lin.) there are two principal varieties ; 1. Time sweet orange, including the China orange, the Pm mgal orange, and similar kinds ; and, 2. The bitter orange, including the Seville orange, and other varieties called bigarades by the French. The
Seville orange-tree produces its fruit more readily in this country, and has larger and more beautiful leaves than the China orange the former is therefore more generally cultivated, but the latter also succeeds very well in some places. There are, besides, the willow-leaved or Turkey orange, the dwarf or nut-meg orange, the double-flower ing, and many other varieties, some with the leaves varie gated yellow and white.
Sir Francis Carew is said, by Mr Lyson, (Environs of London, vol. to have introduced orange-t•ees into this country, in the reign of Elizabeth ; but whether he brought plants, or raised them from the seeds of oranges hrought home by Sir Walter Raleigh, is not clear ; it may be re marked, however, that it has long been known from ex perience, that in this climate orange plants raised front seed spew no inclination to produce fruit ; whereas Sir Francis Carew's yielded plenty of fruit. What is further curious in the history of these early orange trees is, that they were planted in the open border, and protected dur ing winter merely by a moveable shed. They grew on the south side of a wall, not nailed against it, but at full liberty to spread ; they were 14 feet high, and extended about 12 feet wide. They were finally cut of by the great frost of 1740, after having stood a century and a half. Professor Martyn informs us, (Miller's Dict. in loco), that they had, the year before, been inclosed in a permanent building like a green-house ; and he very justly remarks, that the dampness of new walls, and the want of the usual quantity of free light and air to which they had been ac customed, might probably have killed them, even had the great frost never occurred.
226. The orangeries of this country are supplied in two ways; either by plants raised from the seed, arid budded, marched, or grafted by our nurserymen and gar deners ; or by small budded trees imported in chests from Italy.
The best stocks are common citrons, this tree making strong straight shoots, and receiving readily either orange or shaddock buds; they are procured by sowing ripe citron seeds. Next to these, Seville orange stocks are desira ble; the seeds may be taken ['loin rotten Seville oranges, which are generally the ripest. They are sown in pots sunk in a hark hot-bed, ;Inn, about two months afterwards, each plant is t•ansferr.c1 to a llo-at.r•pot, about five inches in diameter. They are gradually hardened, by ad mitting air, till the end of September, when they are trans ferred to the green-honse for the winter. Next spring they ate forwarded, by bring again plunged in a moderate hot-bed ; hut after midsummer they are hardened as much as possible, and in August they are ready for budding. The buds should be taken from trees in a bearing state, and which are known generally to afford a good crop, pre felling buds from round shoots to those from flat shoots. The plants are again preserved in the green-house through the winter ; and in the following spring, they are once more planted in a gentle hot-hcd, the stocks at the same time being cut off about three inches above the buds : By this means, the stem of the future tree generally grows up straight in one se:ison.