In 1890, while studying the bacteriology of the tubercle bacillus, Robert Koch discovered that the gold ion had the property of inducing bacteriostasis in vitro. This observation was an incentive for further investigation of the chemotherapy of tuberculosis. A knowledge of synthetic chemistry enabled the investigators to prepare gold compounds which theoretically, when given intravenously, would inhibit the growth of the tubercle bacillus. Of these compounds, gold sodium thiosulphate, as prepared by Møllgaard,1was used extensively in the treatment of pulmonary tuberculosis. The assumption that lupus erythematosus was of tuberculous origin led to the introduction of various gold preparations in the treatment of this dermatosis. Schamberg and Wright2were the first to use gold sodium thiosulphate for this disease. When dissolved in distilled water, the product dissociates according to the equation: Na3Au(S2O3)2⇄3Na + AuS2O3+ S2O3 Since