There are lots of things we can blame on mosquitoes — itchy welts, smelly insecticide, the West Nile scare.

But let’s give credit where it’s due. Because the mosquito is also responsible, in a roundabout way, for one of summer’s most storied libations: the gin and tonic.

The story goes like this: When the British military was occupying India in the 1800s, the troops drank quinine water in order to ward off the region’s mosquito-borne malaria. Quinine water tastes pretty nasty, so somebody came up with the idea of mixing it with soda water and adding some sugar. And because the troops were, shall we say, somewhat enthusiastic drinkers, it didn’t take long before someone had added gin to the mixture. Thus the gin and tonic was born.

The British troops brought the drink back home with them to England. But the gin and tonic didn’t arrive in America until after Prohibition. “You couldn’t get quinine tonic over here,” the cocktail historian David Wondrich said. “But starting in the 1930s, the gin and tonic became a hot cruise drink — the kind of thing you’d encounter while you were abroad and then bring back.”

Soon the drink’s bracing combination of bitter, tart, aromatic, and effervescent made it a classic summer refreshment. By 1980, the gin and tonic had become so ubiquitous that Douglas Adams’s book “The Restaurant at the End of the Universe” (the second installment in his “Hitchhiker’s Guide to the Galaxy” series) claimed that 85% of the galaxy’s civilizations had invented a beverage pronounced “gin and tonics,” with examples ranging from jynnan tonnyx and gee-N-N-T’N-ix to jinond-o-nicks and chinanto/mnigs (the latter of which was simply water served at slightly above room temperature).

But these days, with more people eschewing gin in favor of vodka, and consequently fewer bartenders knowing how to work with gin, this classic cocktail has fallen into relative disfavor. “A lot of people think they dislike gin because they’ve only had it mixed terribly,” Mr. Wondrich said. “But a properly made gin and tonic could certainly go a long way toward convincing people.”

So what’s the proper way to make one? The first consideration, obviously, is the gin.By federal law, a gin’s most prominent flavor note must be juniper, but a particular gin’s flavor profile can also include a wide array of other botanicals, such as coriander seed, angelica, lemon, cardamom, fennel, anise, caraway, orange peel, nutmeg, and cinnamon.

“Gin brands have been trying to attract vodka drinkers, so they’ve been introducing subtle, less aggressive gins, which are less juniperheavy,” a spirits journalist, Ron Givens, said. “But those gins aren’t great with tonic, because the tonic obscures their more delicate qualities.What you want is your standard London dry gin, strong on the juniper, like Beefeater, Gordon’s, or Tanqueray — the regular Tanqueray, not Tanqueray 10. Junípero, which has a massive juniper flavor, is good too.”

And don’t overlook the choice of tonic water. Contrary to what you might think, they’re not all the same. The trick, Mr. Givens said, is to matching the right gin to the right tonic.

“If you’re using, say, Junípero gin, you’d use one of the sweeter tonics, like White Rock or Canada Dry,” he said. “But for, say, Plymouth gin, which is already somewhat sweet, you’d want a drier tonic, like Seagram’s or Schweppes, which have a bit more of a quinine quality.” He paused, and then added, “Or at least I assume that’s what I’m tasting in there, since I’ve never actually tasted quinine on its own.”

Actually, almost nobody has ever tasted quinine on its own. But Brian Van Flandern has. He’s the head bartender at Per Se, Thomas Keller’s restaurant in the Time Warner Center (10 Columbus Circle, fourth floor, 212-823-9335). When the restaurant opened in 2004, the bartender was trying to get back to the roots of many classic cocktails, including the gin and tonic.

“I was thinking about tonic water,” Mr. Van Flandern said one recent afternoon at Per Se. “And I thought, ‘Exactly what is quinine, anyway?’ It turns out that it comes from the bark of the cinchona tree, which grows in South America. Companies like Schweppes and Canada Dry use a quinine derivative, but I found a source that brings in fresh botanicals from the Brazilian rain forest, and they supply me with raw quinine powder, ground from the cinchona bark.”

He showed me the powder, which was dark red, a bit like cinnamon.”At first I didn’t know how much to use,” he sad. “I put a teaspoon of it in a glass of soda water, along with a little sugar. And it was horrible! So I cut back on the quinine, and then cut back some more, until I was down to about 1/16th of a teaspoon. At that amount, it’s still bitter but it has a lovely citrus flavor, with hints of grapefruit.”

The next step was to find a suitable vehicle for the quinine. After some experimentation, Mr. Van Flandern settled on Ty Nant sparkling water from Wales. “It has much smaller bubbles than club soda, so it’s less aggressive on the palate.”Tonic water also includes sugar, so he added some simple syrup, along with a bit of fresh lime juice.

And the gin? “I use Junípero,” he said. “It’s very floral, very aromatic, but still with that wonderful juniper flavor.”

And with that, he mixed me a gin and tonic — or, rather, a “tonic with gin Per Se,” as it’s officially called. At my request, he also mixed a more conventional version, using Seagram’s tonic water.

The differences between the two drinks were striking. Mr. Van Flandern’s rendition was bright and crisp, with the lime, sugar, quinine, and gin all clearly evident in the mix. As he’d promised, the Ty Nant water’s smaller bubbles were just effervescent enough without being numbing. I immediately had thoughts of a hot day, a hammock, and a pitcher of this drink. The Seagram’s version was almost harsh by comparison. Imagine a cold bucket of water being upended over your head, as opposed to a relaxing dip in a mountain lake, and you’ll get the idea.

But this magnificence comes at a price: Per Se charges a whopping $20 for Mr. Van Flandern’s creation. But given that Mr. Van Flandern is using fresh quinine powder, it’s a safe bet that you’ll be fully protected against malaria.