The Gin & Tonic is beloved by many, but drink carefully. In excess, its effects can be far worse than a run-of-the-mill hangover.

Jerry the Rug was a carpet salesman whose adult beverage of choice was Martell Cordon Bleu cognac. He chose it, I’d guess, three or four times a night, sometimes more. Trim and boyish-looking, he frequented a midtown Manhattan saloon called Runyon’s, where I used to hang, and one summer night he warned me against ordering another gin and tonic. “You know what can happen to you if you drink too many of those things?” he said.

“Yeah, Jerry,” I said. “You get drunk and fall on your ass.”

“No, much worse,” he said, and then he told me about a guy who died of some nasty complications from obesity. This guy loved his gin; drank at least a quart of it a day for much of his life. But it wasn’t the gin that had ruined his body – it was the tonic.

“You see,” Jerry said, “if you’ve got a taste for gin and tonic, and if you’re drinking a quart of gin a day, imagine how much tonic you’re drinking it with. And here’s what happened: The quinine in the tonic destroyed his adrenal gland, and he couldn’t lose weight. He just got fatter and fatter, and died.”

Considering how many cognacs he had consumed, I was certain that Jerry the Rug had no idea what he was talking about. Turns out, though, Jerry was half-right. According to my brother-in-law the gastroenterologist, it’s not their adrenal gland per se, but their kidneys that gin-and-tonic guzzlers have to worry about. An excess of quinine can cause renal failure. But you’d have to drink, like, a gazillion gallons of tonic water over a lifetime to damage your kidneys, no? “Yes,” the good doctor replied, “or we would’ve started dialysis by now!”

Well, that’s a relief. I’ve grown fond of my kidneys, and wish them no harm. Truth be told, my brother-in-law and I are moderate drinkers. We both recognize that, in addition to an exuberantly squeezed wedge of lime, a G&T requires no more than two jiggers of gin and the right amount of tonic to strike a tasty balance of flavor and strength. And besides, we pretty much confine our G&T consumption to the dog days of summer, the ideal time of year to quaff this deliciously tart thirst-quencher and remember from whence it came.

Many of the world’s most popular cocktails – including the Martini, Manhattan, and Old Fashioned – were invented here in America, but the gin and tonic is a gift from our British cousins. Exactly who among them blessed us with this cool concoction is sketchy. Some sources credit sailors in the Royal Navy, others salute Army officers in India in the early 1800s. What we know for sure though is this: Gin was invented by the Dutch, and then the English got hold of it some 400 years ago and spread it around the world. According to Kingsley Amis, the celebrated British author who wrote frequently and eloquently about drinking: “In the days of the Empire, you were supposed to drink quinine water, the ancestor of tonic, to keep away fever. Someone noticed that the vile stuff went down a little better if you splashed gin into it. What an idea!

Amis preferred his gin with water, not tonic, and I’m confident he’d have disdained the current craze for fancy-schmancy artisanal gins that are proliferating everywhere, even in Brooklyn. Unlike my brother-in-law and a legion of other converts to Bombay Sapphire, Amis favored Booth’s, a bottom-shelf dry gin with a robust backbone of juniper and lesser botanical notes of lemon peel and coriander. His famous countryman – a certain dashing Secret Service agent – was also a Booth’s enthusiast. He was partial to martinis, but knew how to make a helluva G&T when the situation called for it. Like the time he ordered a double gin on ice in a tall glass from the Blue Hills hotel bartender in Kingston, Jamaica. When he got his drink, he asked for a lime, cut it in half, dropped the two squeezed halves into the glass, and then poured in the tonic. He took his gin and tonic out onto the balcony of the hotel, where he enjoyed his drink along with the spectacular view of Kingston Harbor.

You could look it up in Ian Fleming’s Dr. No, which was first published in 1958. Even back then, James Bond was wise enough to switch from his beloved martini to a bracing gin and tonic when the steamy setting called for it.