History of the state of California : from the period of the conquest by Spain, to her occupation by the United States of America : containing an account of the discovery of the immense gold mines and placers, the enormous population of gold-seekers, the quantity of gold already obtained, a description of her mineral and agricultural resources, with thrilling accounts of adventures among the miners : also, advice to emigrants on the best routes, and the preparations necessary to get there : to which is added a brief account of the formation of the government and constitutions of the said state