which has never been harnessed or handled before, and it is only after a long struggle, requiring the utmost skill and strength of the mayoral and his assistants, that it is subdued, great roughness being used in lassoing and throwing it, while it is approached and handled gently in harnessing." The road, like all the main routes in Uruguay, is called the camino real, or royal road, but the roads are all mere tracks over the Campos, chosen so as to avoid the steepest hills and seek the easiest places to ford the rivers. As a rule, the country can be crossed by ordinary stage-coaches on the natural turf in either direction. The landscape is tame and monotonous, disposed for the most part in low, gently sloping downs or ridges, rising from sixty to two hundred feet above the valleys, "covered with grass and generally unbroken by tree, bush, or rock." The ridges are not furrowed by ravines, and show no traces of erosion. Signs of human habitation are rare. In a few instances the view was relieved by two or three ombie-trees (Phytolacca dioica), "large, handsome, shady trees, with soft, pith-like stems." Near Florida were observed groups of stones, like cairns, "consisting of squarish blocks arranged in an artificial-looking manner," a similar formation to which, fifty miles farther west, called Serra, constitutes a true though miniature mountain-range, and has been compared by Dr. Burmeister to the "Teufelsmauern" and "Felsenmeere" of Germany. The district of San Jorge, judging from the rocks of the dividing ridges, rests on a formation of volcanic origin, and is remarkably well watered by the Rio Negro and its tributaries, the Carpinteria and Chileno, with numerous streams flowing through it. The mass of the country is covered with grass but destitute of timber, while the rivers are fringed with montes, dense belts of trees and shrubs. The grass is coarse and bunchy, endures the droughts of ordinary summers, and is profusely adorned with compositæ, yellow and purple oxalis, white, red, and scarlet verbenas, many liliaceous plants, and a fine œnothera. The only native tree on the Campos is a thorny tala (Celtis tala). The montes are of comparatively insignificant area, and are composed chiefly of willows, coronillos, laurels, the fruit-bearing guayavo, prickly climbers, and brush-wood, comprising more than twenty species in all. The larger animals—the jaguar, puma, great ant-bear, and large deer—have nearly disappeared, but the smaller animals and the rodents are well represented. Birds are numerous and extraordinarily tame. Eagles would let the traveler throw clods at them and almost touch them, and the rhea ostrich would allow a man on foot to approach to within seventy yards before walking or trotting off. The most important insect is the leaf-cutting ant, which has been often described. It parcels out the Campos among its communities, the nests of which are generally about a hundred yards from each other, with five or six paths radiating from each till they approach the domains of their neighbors. Along these paths double streams of workers are constantly passing to and from the country, each ant of the returning stream holding aloft a piece of grass, a leaf, or a flower. Gardens must be protected against them by destroying the nests with boiling water or poisonous solutions—a difficult task, which has to be carefully done. Another insect plague is the bicho moro, a blistering beetle, which attacks the potato-fields and eats regularly forward with almost incredible rapidity.—The return-journey to Montevideo was made in a bullock-wagon, a solidly built vehicle with an arched roof of zinc, perched on high, broad wheels made of pieces of wood so skillfully wedged together that every shock made them firmer, and drawn by means of a shaft which is of one piece with the body. The three or four yoke of powerful oxen, which form the team, are driven by a picador, who rides alongside, and the whole train, of which a single one of the wagons is only a member, is under the command of a mounted carretero, or patron. The rate of traveling is estimated at from twenty to twenty-four miles a day, but is largely dependent on the weather.
Physiology of Arsenical Poisoning.—MM. H. Caillet de Poncy and C. Livron, of the Medical School at Marseilles, have found that, when poisoning by arsenic takes place, the phosphorus which exists as phosphoric acid in the brain is replaced by arsenic. The substitution takes place in the lecithine,
