During the Victorian era, curry powder and other spices were sometimes adulterated with mercury compounds, such as bisulfate of mercury, to enhance their color or weight. Mercury is highly toxic and can cause severe neurological and kidney damage. This practice was part of a broader pattern of using dangerous chemicals in food, which was only gradually uncovered by investigative chemists.

The discovery of mercury in curry powder highlighted the global dimensions of food adulteration and the dangers of the spice trade. Poets and writers interested in colonialism and exoticism, like Rudyard Kipling, were aware of these issues, though they often treated them with ambivalence. The theme of poisoned foreign foods also appeared in the literature of the period, reflecting anxieties about immigration and cultural contamination.