The atmosphere at Panama is particularly injurious to people from the northern climes, and great care must be taken by travellers during their stay at that place. It is best to avoid eating fruit altogether; but, if indulged in, it should be in very inconsiderable quantities. Exposure to the mid-day sun is a frequent cause of sickness among the travellers, and should be avoided, as well as exposure to the rain. During the rainy season, the _vomito_ is often prevalent among the inhabitants of Panama, and is generally a fatal disease; but there is a great deal less travel across the Isthmus during that season, on account of the sickliness of the climate and the difficulties of the route. A sort of bilious fever and dysentery are the most common forms of disease among travellers from the north; but both may be avoided by proper care. From Panama, steamships of superior size and accommodation, convey passengers to San Francisco. Starting from the front of the city, the beautiful bay, with its semi-circular shores skirted with green foliage and inclosed with high mountains, and the lofty islands of Flamingo, Perico, Taboga, and others, present themselves to the view. At the island of Taboga, all the vessels that come into the bay obtain their supplies, and the Pacific Mail Steamship Company have established their depot for coal, &c., on its shores. After obtaining all the necessary supplies the steamship moves out of the bay, rounding Point Mala. The voyage upon the Pacific, with all its variety of incident and scenery, then commences. The principal annoyance of travellers is the almost intolerable heat of the sun and furnaces of the steamship united. Water-spouts and different species of whale are frequent sights. North of the Gulf of Tehuantepec, the steamer nears the land, and the bold mountain coast of Mexico breaks upon the view, and, at night, the passengers enjoy a view of the glaring light produced by the burning volcano of Colima; though the volcano itself is but imperfectly seen being at the distance of ninety miles from the vessel. Soon after this fades from the view, the islands off the town of San Blas appear, and an immense white rock, isolated from the sea, serving as a lighthouse to ships steering for the port. At San Blas, the steamships remain some time, to obtain supplies of coal, fresh fruits, and provisions. These indispensables having been procured, the vessel proceeds upon her voyage. Cape Corientes next appears, and, soon afterwards, the entrance to the Gulf of California is approached; and then, Cape San Lucas, the extreme southern point of California, with its mountains and rocky shores, is hailed by the traveller as the first portion of the "promised land" that greets his sight. Passing along the western coast of the peninsula, the island and bay of Magdalena appear, with shores three or four thousand feet above the sea. Next, the towering ridges of Cerros Isles are passed, and the