Death of thx oldest inhabitant of San Francisco.—A gloomJias been cast over a large portion of this community in consequence of the sudden death of Don Nathan Spear, probably the oldest inhabitant of San Francisco. He had been for some time past afflicted -with sickness in a I combined farm, and suffering intensely ftomdia-ease of the heart. He breathed his last at the residence of W. H. Davis, in tins city, on Sun-1 day, 21st inst. An obituary notice prepared for this number of the paper has been crowded out; but will appear next week.