OWEN, Charles. An Essay towards a Natural History of Serpents, London: for the author, 1742, 2 parts in one, 4°, 7 engraved plates, woodcut head-and-tail pieces (title detatched and with perforation and library stamps, all but one of the plates just cropped in plate area, not affecting the image, three stamped on verso), library cloth [Nissen ZBI 3033] -- Silas Weir MITCHELL (1829-1919). Researches upon the Venom of the Rattlesnake, Philadelphia: Collins for the Smithsonian Institute, 1860, large 4°, 12 woodcut illustrations (title and one text leaf with perforation stamp), contemporary cloth (disbound). Provenance: I. & II. JCL (2)