We have the following record in evidence of the masses of silver extracted at Arazuma. Don Domingo Asmendi paid duties on a piece of virgin silver which weighed 275 lbs. The king's attorney (_fiscal_) brought suit for the duties on several other pieces, which together weighed 4033 lbs. Also for the recovery, as a curiosity, and therefore the property of the king, of a certain piece of silver of the weight of 2700 lbs. This is probably the largest piece of pure silver ever found in the world, and yet it was discovered only a few miles distant from the contemplated track of our Pacific Railroad. I might continue enumerating the instances of mineral wealth brought to light in these two states, Sonora and Chihuahua, if I supposed it would be interesting to my readers; but as they have heard enough of silver, I may add that rich deposits of gold were found at Molatto in 1806, and a still greater discovery of gold was made a few years ago. In this latter discovery, the poor diggers suffered so much from thirst that a dollar was readily paid for a single bucket of water, and at length, by reason of the drought, this rich _placer_ had to be abandoned. FUTURE OF SONORA. Such is Sonora, a region of country which combines the rare attractions of the richest silver mines in the world, lying in the midst of the finest agricultural districts, and where the climate is as attractive as its mineral riches. But its richest mineral district is near its northern frontier, and is almost inaccessible, and can never be advantageously worked without an abundant supply of mineral coal for smelting; nor can any of its mines or estates be successfully worked without greater security for life and property than at present exists. The capitalists of Mexico will not invest their means in developing the resources of Sonora, and in consequence, the finest country in the world is fast receding to a state of nature. I found in the Palace at Mexico a copy of the last report of the Governor of Sonora upon the state of his Department, in which he mentions, among many other causes of its decadence during the last few years, the extensive emigration of its laboring population to California. Extravagant as are these statements of the mineral riches of Sonora, they probably do not come up to the reality, as the largest of them are founded on the sums reported for taxation at the distant city of Mexico, when it was notorious, as already stated, that a large portion of the silver was fraudulently concealed in order to avoid the taxes. Such concealment could be successfully carried on in a region so distant and inaccessible as Sonora was in the time of Philip V., for it was in the reign of that idiot king, before the liberal mining-ordinances of Carlos III., that the Sonora mining-fever broke out.