It is not long, since a list of the peons who had escaped from the other side of the Rio Grande was published, and bitter complaints made by their masters to the Mexican Government, which was petitioned for redress! It is said that some proprietors own thousands, and they are a part of their estates. It is probable that neither slavery nor peonage can continue on the borders of the Rio Grande. During our military operations a large number of persons were freed by earning the means of paying the debts for which they were bound. ------------------------------------------------------------------------ APPENDIX. [_From the Republic._] MESSRS. EDITORS: Some time last Spring, I published in the “Commercial Journal,” of Pittsburgh, some views on the subject of the California gold region, which have been confirmed by observations on the spot, published in the “_Alta California_,” and by accounts still more recent from that country. In order to understand the views referred to, it is necessary, in the first place, to give a sketch of the geological features of the country. A valley of six hundred miles in length, and from fifty to a hundred in width, is formed by the Sierra Nevada, or Snowy range on the east, and by the coast range on the west. This valley is watered by two rivers, the Sacramento and the San Joachim; one rising due north, the other due south, and running towards each other; after uniting their waters they enter the bay of San Francisco, which partly bounds the western side of the valley. These rivers may be said to wash the base of the Sierra Nevada, their waters being supplied, almost exclusively, by streams which take their rise in that range of mountains. In this manner they form a continued line although coming from opposite directions, receiving the drainings and detritus brought down by the innumerable torrents which cut the sides of the Sierra. The alluvial and diluvial deposites are, therefore, almost exclusively on the eastern side; and this accounts, also, for the overflow of the river on that side. On looking at the map of Colonel Fremont, I was struck with the extraordinary number of these ravines. They look like so many streaks on the map, or, rather, lines drawn by artificial agency; but that agency is the sudden melting of the snows, and heavy rains of that climate. One cause of this great quantity of water discharged by the short mountain torrents, is the want of sufficient elevation of the mountain, in that latitude, to retain the snows until they can melt gradually, as is the case of the Andes of Peru and Chili; and yet sufficiently elevated to receive a great depth of snow. This, when melted by the rains, rushes down with great force, carrying detritus along with it,