Haygarth’s January 1799 fictitious-tractor experiment at Bath General Hospital is the founding placebo-controlled trial in the modern Anglophone medical literature. Five chronic patients (including the locked-elbow case Wootton emphasizes at p.167: pain relief was reported in the soft tissues while the anatomically locked joint remained immobile, establishing both the reach and the limit of the placebo response) were treated with the wooden imitations and reported the same relief as had been documented with the original metallic tractors. The experimental design (carved wooden imitations matched visually to the patented metallic original, blinded patients, matched clinical conditions, comparison of reported outcome) is the methodological prototype of every subsequent placebo-controlled clinical trial. The result was independently replicated by Richard Smith at Bristol Royal Infirmary in 1799 and has been re-reproduced under modern controlled conditions in 20th-century placebo-effect studies. The intervention claim (the Perkins Tractor cures-by-metallic-action) is refuted; the methodological claim (that an elite-targeted commercial intervention can be disconfirmed by a simple imitation experiment) is the founding methodological priority case for this archive’s analytical tradition. Endpoint type is encoded hard rather than surrogate because the experiment measures the same clinical outcome (reported relief) that the disconfirmed intervention claimed to deliver, not a biomarker proxy. The word ‘placebo’ was already in medical circulation by 1799 (it appears in George Motherby’s New Medical Dictionary, 1785), but not yet in the systematic operational sense of a control in a comparison; Robert Hooper’s Lexicon Medicum (1811) later gave a classic definition, and the 1832 Russian homeopathy trials Wootton describes at p.170 used the concept operationally. Haygarth’s own vocabulary is ‘imagination’.”