Until the coming of Alfalfa, San Luis was chiefly interesting for its mineral possibilities. Even now, after Salta and Jujuy, it is the most sparsely populated of the Argentine Provinces. Nevertheless, it now has large areas under wheat; and sandy salty tracts which not long ago, in common with similar tracts in the West of the Province of Buenos Aires and in the Territory of the Pampa Central, were looked on as useless deserts, are covered with an extraordinarily luxuriant growth of lucerne. The salty nature of the soil is favourable to this valuable forage plant, and its tap roots find their way easily through the sandy surface to the closely adjacent damp subsoil and surface waters. Irrigation is destined to play an important rôle in other parts of San Luis. At present this Province runs Santa Fé very close in point of number of Live Stock; though the general average of quality is a good way behind that found in the “home” Provinces or Córdoba. San Luis cultivates an appreciable quantity of good table grapes, and, as is noticed in another chapter, also produces some wine. The Province is intersected in its North and Central parts by four lines of the Buenos Aires Pacific Railway and in the South by two of the Buenos Aires Western Railway. It is evident that the mineral deposits of San Luis were worked in the prehistoric days prior to the Spanish Conquest, but little has been done to exploit them in modern times except as regards the beautiful green marble, commonly called Brazilian Onyx, large quantities of which are exported. Gold mining has been attempted in modern times, but without as yet any very appreciable results. San Luis, however, produces a certain regular supply of Wolfram. The people of San Luis are frequently accused of indolence. Certainly the Province is not a wealthy one, nor do its inhabitants appear over alert to seize the opportunities which nature and modern methods combined now offer them. SANTIAGO DEL ESTERO This Province is bounded on the North by the Province of Salta and the National Territory of Formosa, on the West by the Province of Tucumán and Catamarca, on the East by the National Territory of the Chaco and the Province of Santa Fé and on the South by the Province of Córdoba. Irrigation has led to a considerable development of wheat-growing in this Province and to irrigation it must chiefly owe its future progress; for, in its almost tropical climate, rain only falls in the summer months and usually is absorbed almost as soon as it falls by a sandy and dusty soil. The average temperature of Santiago del Estero is highly favourable to maize, but, here again, the question of water supply arises, only to be met by artificial means. Already principal and subsidiary irrigation canals have been constructed in the areas through which pass the two rivers of the Province, the Dulce and the Saladillo, and further works of the kind are in active contemplation.