537. Sometimes the characters of the green-house and the conservatory are to a certain extent combined in one house. In particular, some ornamental climbers are plant ed in the borders, trained against the rafters and pillars, and often led in festoons from place to place. Several species of Passiflota, such as ccerulea, au•antia, and in carnata, and of Glycine, become in this way very elegant, and the large bell flowers of Cobbea' scandens make a fine appearance ; with different species of Convolvulus, and the Maurandia semperflorens. The Caper-bush, al ready noticed, § 405. is at once showy and in some mea sure useful.
538. In a few fine gardens, where the cultivation of curious plants is much attended to, a separate heath-house is erected, and appropriated to the numerous Eric from the neighbourhood of the Cape of Good Hope. This tribe of plants, it is justly remarked by Professor Martyn, has within these few years " risen from neglect to splendour.' Miller, in the edition of his Dictionary published in 1766, mentions only five sorts, four of which are indigenous to this country, and the fifth a native of the south of Europe. The stores of the Cape were then nearly unknown. In 1775, Mr Francis Masson, travelling botanist to the king, sent home many new species from Southern Africa ; and the same botanist revisited that country in 1787, and was equally successful in his researches. More lately, Mr Niven of Edinburgh, by extending his travels, made a rich harvest among the same tribe of plants. The Cape erica are now about two hundred in number, and many of them both beautiful and fragrant. In construction, the heath-house differs in no respect from a small green-house with a low roof. The plants thrive best in a light rather poor soil ; such as a mixture of bog-earth, light loam and sand. They are propagated chiefly by cuttings ; the cut tings preferred arc very small, inserted closely together in fine soil, sifted over with very pure and fine sand, and covered with small crystal glasses, so as to prevent eva poration ; the pots are kept in a moderate heat, but shaded. Cuttings of E. retorta, articularis, and several others, do not grow without great difficulty : such species are there fore often layered. Several kinds ripen their seeds in this country ; and by sowing these, great numbers of plants are frequently raised.
Hot-houses.
539. The hot•liouscs for exotic plants have already been mentioned, under the title of Dry Stove and Bark Stove, (§ 199, 200). It was there observed, that in the latter some of the more delicate kinds of grape vines are often trained along the rafters, and that pots with kidney-beans and strawberries are sometimes placed on the side shelves.
In first rate gardens, where the stove is entirely appro priated to ornamental plants from tropical climates, the house is sometimes formed of glass on all sides, those plants which naturally grow in shady woods in their own country being placed on the north side of the house. It may here be mentioned, that a book, in folio, on the Con struction of Hot-houses, Green-houses, ttc. has been published by Mr George Tod, including plans and eleva tions of some of the fine stoves for exotics at Kew gardens, which were executed by Mr Tod, under the direction of the late distinguished Mr Aiton.
Many curious and beautiful plants might be mentioned as deserving a place in the bark stove, but only a very few can here be named. Among the curious may be noticed, the Date-palm tree (Phcenix dactylifera); the Sago-palm (Cycas revoluta) ; the Cyperus Papyrus of Egypt, which afforded the scrolls of bark on which the ancients wrote with the stylum ; the Coccolobo pubesccns, remarkable for producing the largest round-shaped leaves in the world; Hernandia sonora, or the whistling tree of the West Indies ; Musa paradisiaca, the plantain tree, and M. sapientum, the banana ; several of the larger species of .Acacia, which yield gum arabic; with others which, in our Eastern or Western possessions, afford well known commodities, such as the sugar-cane,the coffee-tree, the pimento and the clove-tree, the indigo plants, and the Ficus elasticus, from which the substance called Indian rubber is procured.
The Papaw-tree (Carica papaya) deserves a place in every large hot-house, on account of its possessing a re markable property, which has been long known to those who have resided in the West Indies, but which has only of late been particularly 'described in this country by Dr Holder,—that of intenerating butchers-meat or poultry. This singular property is not even hinted at in the last edition of ,Miller's Dictionary. The juice rubbed on beef or mutton has the effect of rendering the meat as tender as veal or lamb, without injuring its other qualities. In deed it is affirmed, that if a fowl be hung against the trunk of a papaw-tree, it becomes intencrated in a short space of time by mere proximity ; and that the oldest poultry may thus be rendered as tender as chickens. In stoves in England, the papaw-tree has been known to attain the height of twenty feet in three years, and to produce its flowers and fruit : it is not however a durable plant.