Where would the gin revolution be without the existence of tonic water? The most basic of mixers, tonic is no more complicated than quinine dissolved in carbonated water. Originally used as a preventive health care measure against malaria, tonic now has much less quinine in it making it more drinkable (and less medicinal). It is also now very often bottled with a hint of flavour, either to make it a tastier drink on its own or to match perfectly with a gin – for a famous gin and tonic!