Sir : We frequently see the Mulatos mine, of Sonora, mentioned in Southern Arizona, and occasionally in New York papers. It is always located wrong. A late Arizona paper speaks of it as the " Sahleneripa or Mulatos mine." Its name is the Mina Blanco y Colorado, or the White and Red Mine. It is so called on account of its colors. It is located on an immense ledge of ore running along the south side of the town of Mulatos, and is traceable to the river of that name nearly four miles distant. The town of Sahuaripa is sixty miles distant, and is the headquarters for the mining Parita of the canton in which the Blanco y Colorado occurs. While it is not a rich mine, in the usual acceptation of that term, it is really so in the immense quantity of ore it contains. It is simply a huge quarry of gold ore. The body-rock, so to speak, carries about $5 per ton of free gold, and through the ore run little streaks of exceptionally rich metal in which the gold is plainly visible to the naked eye. The low-grade ore is crushed in the mills, of which there are two—one of thirty, and one of twenty stamps. The rich ore is worked in arrastras, to seven of which mules furnish the power, the other three being supplied with water-power. The latter are located near the river. It is estimated that each stamp will crush five tons of ore per day. The gold is caught in the riffles, in sluice-boxes. The lowest opening on the mine is about forty feet above the level of the arroyo ; and when I saw it, there was no working below that level, except a 16-foot sump or well. The mine is about to be sold, I understand, for $2,000,000. General Rosecrans, about three years ago, could have bought it for $300,000. A year later, Mr. J. Flournoy, acting for outside capital, was charged $1,000,000, and even then the owner weakened. Now, it has reached $2,000,000. Situated so far back in the mountains, approachable only by trail, transportation high, labor unreliable and irregular, so far from the Guaymas & Hermosillo Railroad that it can not count among the conveniences, it seems a fabulous price; but from my knowledge of it, and I know it well, I should say that it was worth it. The owners are two brothers, one of whom lives at Guaymas, and the other at the mine. The latter is known as Don Socario Aguayo. I am drawing upon my memory for the foregoing ; but I am satisfied of its correctness. I have full notes, but they are not available.

Donald Robb, Arizona Silver Belt.