Glass bottle with a glass stopper that is covered with a piece of leather with string wrapped round. White powder inside. Handwritten label reads "James Powder". Second label has printed company name "Twinberrow, Dispensing Chemist." James’s Powder, or more properly Dr. James’s Fever Powder, was one of the most ubiquitous patented medicines from the mid-eighteenth century to the early twentieth century. Patients included George III, Oliver Goldsmith and Horace Walpole, who claimed the powders ‘can cure most complaints that are not mortal, or chronical’. Patented in 1746, the remedy was the subject of numerous attempts to establish its formula. This [in 1791] private analysis (i.e. not on behalf of the Royal Society) established that the powder consisted of antimony (antimony potassium tartrate; used at one time as an emetic and as a treatment for trypanosomiasis (parasitic infections) but is very poisonous and is no longer used as medicine) and calcium phosphate, and it was Pearson’s formula that was adopted by the first British Pharmacopoeia in 1864. Pearson, a doctor and one of the most famous medical lecturers of his day, was convinced that something was missing, although his detailed descriptions in the end tell us nothing about what the drug did. There is no modern evidence of its usefulness, and even with modern fever-reducers such as paracetamol there is still debate about how they work.
Source: Daniel Glaser, Wellcome Trust.