The Elderflower Collins
A popular example of this category is the Tom Collins. The name has its origins in John Collins, head bartender at Limmer's Hotel in London. His signature drink contained genever, lemon juice, sugar and soda and was a popular drink in the 1830s. The drink made it to New York in 1850 when a British officer taught it to the bartenders at the Clarendon Hotel. It was soon changed into Tom Collins and turned up in Jerry Thomas new edition cocktail book.
A collins is a sour topped with soda, served over ice in a long drink glass.