So if I was going to make an authentic, “Englishman wearing a pith helmet and trying not to get malaria”-style gin and tonic, how would I go about that?

Also, I thought the gin was for making the tonic water palatable. The tonic water I’ve had is pretty awful by itself and the gin definitely brings something to the table in terms of moderating the flavor. I have to imagine that any tonic that actually worked would taste even worse.