Persil soap powder was first produced in 1909 by Crosfields, a competitor of the Lever Brothers, who merged with them in 1919. The name comes from its original ingredients - perborate and silicate. The 'Persil Washes Whiter' theme was launched during World War II to encourage households to spend their rationing soap coupons on Persil. It remains one of Britain's leading washing powder brands today. This image is taken from a slide which was projected in cinemas in the 1950s in the interval between films.
© Michael Martin / Science & Society Picture Library