Vichy Pastilles are a French confectionery produced in the town of Vichy, department of Allier, France. Sometimes called pastilles of Vichy (French: pastilles de Vichy or pastilles Vichy), they are recognizable as a white, octagonal type of candy pastille bearing the word "Vichy" in all-caps.
Vichy Pastilles Wikipedia
In the 19th century, they were originally made purely from bicarbonate of soda and taken for their digestive properties. Empress Eugénie de Montijo is said to have been a fan. Later, they were made with mineral salts extracted from the local spring water. Nowadays, they include sugar and are flavoured with mint, lemon, or aniseed.
The Vichy Pastilles brand now belongs to Cadbury France, a division of Cadbury (Cadbury Schweppes until 2008).