Roger — welcome to the GMB.
Answer to your question is "Fizzy drinks". I've seen both chemist's soda water bottles and chemist's soda syphons before. Chemists often did a lot more than just dispense drugs. See the business card about half way down this link for an interesting variety of products and services (including soda water and lemonade) offered by a chemist:-
http://www.mkheritage.co.uk/mkm/stonystratford/docs/shops.htmlBernard C. 8)