The lands on which cultivation has been attempted occupy a narrow space between the coast ranges and the sea; it seldom exceeds in width thirty miles, and is often reduced to ten by the obtrusion of some mountain spur. East of this range no plough has ever travelled; no furrow has ever been turned in the long valley of the San Joaquin; and if the other sections of this valley correspond to those over which I passed, there can be very little encouragement for the introduction of husbandry. The soil is light and gravelly; the grass meagre and sparse; even the wild horses and elk seek its margin, as if afraid to trust themselves to the Sahara of its bosom. Still, in some of its bays, the evidences of fertility exist, but as a district it will never add much to the agricultural wealth of California. The valley of the Sacramento has many localities of great fertility; but few of them, as yet, have been subjected to the plough and harrow; their adaptation to agriculture is inferred from their vigorous vegetation. The same evidences of productive force cover several tracts north of San Francisco, on the Russian river, and in the vicinity of Sonoma. But the most fertile lands in California, as yet developed, lie around the missions of Santa Clara and Santa Cruz, through the long narrow valleys of San José and San Juan, along the margin of the Salinas, through the dells of San Louis Obispo, and in the vicinity of los Angeles. These, and other insular spots, may be made perfect gardens; but take California as a whole, she is not the country which agriculturists would select. Her whole mining region is barren; nature rested there with what she put _beneath_ the soil. You can hardly travel through it in midsummer without loading your mule down with provender to keep him alive. The productive forces of such a state as New York, Ohio, or Pennsylvania, sweep immeasurably beyond the utmost capabilities of California. It is the _golden_ coronet that gives this land her pre-eminence, and puts into her hand a magic wand, that will shake for ages the exchanges of the civilized world. TUESDAY, JUNE 12. At the return of Gen. Kearny, the command of the military posts of the country, the suppression of popular disturbancies, the protection of property from the incursion of the Indians, and the collection of the custom-house revenues have devolved on Gen. Mason. To these complicated duties he has surrendered his energies with an unwearied fidelity and force. No one great interest confided to his indomitable activity has languished. He has derived indispensable aid from the intelligent services of Col. Stevenson, Maj. Folsom, Capt. Halleck, and Lieut. Sherman, of the army, and Lieut. Lanman, of the navy. These officers, and others that might be named, without any increased compensation, and subjected to heavy expenses, have cheerfully discharged the onerous duties devolved upon them by the condition of the country.