SIR,--Although I have not the honor of a personal acquaintance with you, I have no hesitation in making the present appeal to your patriotism and wisdom, not doubting but that I shall find in the great and growing interest of the subject to the country at large, and particularly to that portion of the Union over which you preside with so much dignity and discretion, a sufficient apology for occupying so much of your valuable time, as will enable you to give the present communication an attentive perusal. I have recently returned from a _geological_ excursion to Virginia. I entered the state near the head waters of the Potomac, passed thence to Winchester, followed the course of that fine valley to the Natural bridge; retracing my steps, I turned westwardly at Staunton, crossed the mountain at Jennings's gap, and visited the justly celebrated medicinal springs in that region; returning, I went from Staunton through Charlottesville to Richmond, and down the James to its mouth. When this tour is taken in connection with a former visit to Wheeling, it will be conceded that I have seen enough of the state, to enable me to form a rough estimate of its geological and mineralogical importance; and I do assure you, sir, that although my anticipations were far from being meager, I was astonished at the vastness and variety of interesting objects in that department of natural history, that were constantly developing themselves, inviting the mind of man to reflection, and his hands to industry, and displaying at every step the wisdom and beneficence of the great Creator.