Gin and tonic is usually garnished with a slice of lime. The soda that's name was invented in an establishment is not garnished this way. Henry Bain sauce was first served at this establishment.
The Old Fashioned is a cocktail made by muddling sugar with bitters, then adding alcohol, such as whiskey or brandy, and a twist of citrus rind. 
A gin and tonic is a highball cocktail made with gin and tonic water poured over ice. 
 It is usually garnished with a slice or wedge of lime. 
 Sometime in the 1880s, the club was the birthplace (by name, not invention) of the Old Fashioned, possibly the first mixed drink to be called a cocktail. 
Henry Bain sauce is a condiment for meats, first served at the Pendennis Club in Louisville, Kentucky. 
