134 



THE POPULAR SCIENCE MONTHLY, 



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 sub- 

 dued, 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 land- 

 scape 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 ob- 

 served groups of stones, like cairns, "con- 

 sisting of squarish blocks arranged in an 

 artificial-looking manner," a similar forma- 

 tion to which, fifty miles farther west, 

 called Serra, constitutes a true though min- 

 iature mountain-range, and has been com- 

 pared by Dr. Burmeister to the " Teufels- 

 mauern " and " Felsenmeere " of Germany. 

 The district of San Jorge, judging from the 

 rocks of the dividing ridges, rests on a for- 

 mation of volcanic origin, and is remarkably 

 well watered by the Rio Negro and its tribu- 

 taries, the Carpinteria and Chileno, with nu- 

 merous streams flowing through it. The 

 mass of the country is covered with grass 

 but destitute of timber, while the rivers are 

 fringed with monies, dense belts of trees and 

 shrubs. The grass is coarse and bunchy, 

 endures the droughts of ordinary summers, 

 and is profusely adorned with compositce, 

 yellow and purple oxalis, white, red, and 

 scarlet verbenas, many liliaceous plants, and 

 a fine Oenothera. The only native tree on the 

 Campos is a thorny tala ( Ccltis tala). The 

 monies are of comparatively insignificant 

 area, and are composed chiefly of willows, 

 coronillos, laurels, the fruit-bearing gua- 



yavo, 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 dis- 

 appeared, 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 trot- 

 ting off. The most important insect is the 

 leaf-cutting ant, which has been often de- 

 scribed. 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 solu- 

 tions a difficult task, which has to be care- 

 fully done. Another insect plague is the 

 bicho moro, a blistering beetle, which at- 

 tacks 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 carrctero, 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 Iccithine, 



