1931: Like most Western mothers in China, Lucy Soothill hired an amah to care for her baby. The amah was generally reliable, but not always. On one occasion Soothill discovered that her daughter’s skin was “irritable and red”, and when she kissed her, she noticed a “salty sharp taste”. On a hunch, Soothill checked the puff box in the baby’s basket and found that the contents had the same distinctive taste. Instead of powdering the baby’s skin with talcum, the amah had been using “extra strong American baking-powder”.
Source: Lucy Soothill, A Passport to China: Being the Tale of Her Long and Friendly Sojourning amongst a Strangely Interesting People (1931), p. 55