the discovery from experiments in his own family, availed himself of its advantages by purchasing a set of the Tractors for their use." Benjamin Perkins was a bookseller and introduced the tractors to London. There a Perkinsian Institution for the benefit of the poor was founded under the presidency of Lord Rivers. In 1798, Benjamin published The Influence of Metallic Tractors on the Human Body. In October 1799, an advertisement in The Times said that "The tractors, with every necessary direction for using them in Families, may be had for 5 guineas the set, of Mr. Perkins, of Leicester Square; or of Mr. Frederic Smith, Chemist & Druggist, in the Haymarket". Aylmer Bourke Lambert, a British botanist, is on record as having written in January 1800 to Richard Pulteney of Blandford (now Blandford Forum), in the English county of Dorset, as follows: "I breakfasted with Sir Joseph [Banks] on Monday morning who is recovered from the Gout and in high Spirits. We had a good deal of laughing about the Tractors. Perkins has published several Cases communicated by my Father, and presented me with a copy of his Book." Shortly before his death Elisha Perkins also invented purported antiseptic medicine and used it for dysentery and sore throat. Perkins also claimed to have discovered a cure for yellow fever. This consisted of vinegar with muriate of soda which he tested in New York City during an outbreak in 1799. The cure had no effect and Perkins contracted the fever and died. After Perkins' death, British physicians began to have doubts about his tractors. In 1799, Dr. John Haygarth conducted a test in which he treated five rheumatic patients with wooden tractors that were made to resemble the metallic ones. Four of them reported that the pain was relieved. The next day the patients were treated with metallic tractors with the same results. Dr. Haygarth reported on his findings in a publication entitled On the Imagination as a Cause & as a Cure of Disorders of the Body. Attempts to use the tractors to cure animals proved futile. By this time, Perkins had numerous influential supporters and the sale of the tractors continued. In 1803, Thomas Green Fessenden published his poem "Terrible Tractoration" in favor of Perkins and as a satire on other physicians. Perkins' son died in 1810. After that the popularity of the tractors began to wane. In 1932,