This sign in Brockley proudly offers Meggezones at 2/4 (about 12p in decimal). There's still a chemist there, and Meggezones are still being made, but you'll need a few pounds rather than a few shillings to buy a packet.
Meggezones are menthol pastilles (they also used to contain peppermint, licquorice, chloroform and benzoin), whose strange name comes from the firm's founder, a Mr Meggeson. He started the company in 1796, and by the early nineteenth century it was making a range of syrups, sweets and lozenges for coughs and colds at its Bermondsey factory. Other products included dyspepsia tablets and lemon barley water. Today, the brand is owned by multinational Schering Plough.