382. The botanic garden of Heidelberg is small, having formerly been the burial-ground of a convent; this building being metamorphosed into a museum. The garden is fully stocked with plants, arranged according to the system of Linnï¾µus. There is a greenhouse and a hothouse, with sloping glass roofs somewhat in the English manner. These are covered at night, and during severe weather, by wooden shutters, hinged at the top, and raised and lowered by cords and pulleys communicating with weights in the buck sheds. In the greenhouse wo found Vallisneria spiralis; in the open ground, rhododendrons have survived three winters, with only a slight covering at their roots. In the summer-time the greenhouse plants are taken out, and plunged in borders of sand, where they grow vigorously, and flowor beautifully.