These pages from the 1867 BP are the first official formulae for five inhalation (vapour) medicines; hydrocyanic acid, chlorine, conia (Hemlock), creosote and iodine. Hydrocyanic acid - was used for the treatment of dry cough, however, in large doses it is lethal as it can paralyse respiration. Vapour of hemlock was also used as a treatment for cough. Vapour of creosote was used as a treatment for tuberculosis and bronchitis.