Group of (4) 18th and 19th century Medical books

Group of (4) 18th and 19th century Medical books, to include: ''Lectures on the Duties and Qualifications of a Physician,'' by John Gregory, 1772, London: Printed for W. Strahan and T. Cadell, new edition, title page stamped ''Geo. R. Brush, M.D., US Navy, Sayville Long Island, New York'', 238 pages, (minor cracked front board, foxing, tanning); ''Observations on the Changes of the Air and the Concomitant Epidemical Diseases,'' by William Hillary, 1811, Philadelphia: B.& T. Kite, 260 pages, (foxing, tanning, staining); ''A Treatise, on the supposed, Hereditary Properties of Diseases,'' by Joseph Adams, 1814, London: Printed for J. Callow, with ''College of Physicians and Surgeons of the University of the State of New-York'' label to interior front cover and inscribed ''George R. Brush, Sayville, L.I., July 15th, 1859'', 125 pages, (foxing, tanning); ''Medical, Geographical, and Agricultural Report of a Committee appointed by the Madras Government,'' 1816, London: Printed for Black, Parbury, and Allen, with folding map of ''Districts where the Epidemic Fever prevailed..'', 170 pages, (image bleeding, foxing, tanning). Each book approximately 8-1/2''l, 5-1/2''w. Provenance: Acquired by descent from Dr. George R. Brush, of the settling Brush family of Southold, Long Island, New York.