 Hunter reconstructed surgical knowledge from scratch; refusing to rely on the testimonies of others he conducted his own surgical experiments to determine the truth of the matter.To aid comparative analysis, he built up a collection of over 13,000 specimens of separate organ systems, from the simplest plants and animals to humans.Hunter greatly advanced knowledge of venereal disease and introduced many new techniques of surgery, including new methods for repairing damage to the Achilles tendon and a more effective method for applying ligature of the arteries in case of an aneurysm.