Atlas Obscura:

Soda jerks became known across the country for… esoteric slang. They were often virtuosic wordsmiths, with a gift for puns and riffs. And, at a time when the United States was nuts for all things ice-cream, they were at once “consummate showmen, innovators, and freelance linguists of the drugstore stage,” writes Michael Karl Witzel in The American Drive-In. “America’s soda jerk became the pop culture star of the Gilded Age.” …

In 1936, English professor Harold W. Bentley conducted a full-scale investigation into the cabalistic mumbo-jumbo of these young New Yorkers, publishing his findings in the journal American Speech. They were so semantically inventive, he wrote, that they had become a tourist destination in their own right, skillfully “serving colorfully named concoctions [and] providing an attraction much stronger than stone and concrete piled high. To foreigners in search of local American color, the soda fountains are as good as made to order.” (In fact, soda jerks were slinging lingo all over the country—though many of the terms Bentley described are specific to the Big Apple.)

There was a competitive edge to it too, Bentley explained: “The bright boys behind the marble counters have extended themselves to outdo the other fellow with fantastic, grotesque, or witty labels for the food combinations from the kitchen or the refreshments spouting out of those fascinating faucets which decorate the bar.”

An order of a simple float might yield a shout of “Burn it and let it swim!” A more complex chocolate malted milk with chocolate ice cream: “Burn one all the way.” If you nixed the ice cream and added an egg, your server would “twist it, choke it, and make it cackle.” Coca-Cola flavored with cherry might be “Shoot one in the red,” or the steamier “Make it virtue.” Drinks without ice “held the hail.” Big drinks were “stretched”; small ones were “short.”

The term used in one drugstore might not hold in another. In one soda fountain Bentley visited, an order of “Black and white” meant a chocolate soda with vanilla ice cream. But in another, it signified black coffee with cream—and in yet another, a chocolate malted milk. A simple glass of milk might variously be called “cow juice,” “bovine extract,” or “canned cow,” while water went by everything from “aqua pura” to “city cocktail” to the deeply unappetizing “Hudson River ale.”

Many of these terms were used in only one soda fountain—or two at the most, with terms swapped around and mixed up almost as vigorously as the drinks they described. There was a certain amount of pressure to keep them up-to-date: An order of five small scoops of vanilla ice-cream topped with whipped cream, a maraschino cherry, and crushed fruit had the nickname “The Dionne Surprise,” for the famous Canadian quintuplets born in 1934.

Often, the terms were a cocktail of performance and posturing. They were something for tourists to go out of their way for, and a distraction for Times Square showgirls out for a breather between rehearsals, as they sat on high red upholstered stools and nursed dishes of vanilla ice-cream. There was also something compelling about a kind of indecipherable secret language, where guessable terms (a “Traffic Light Sundae” was three scoops of vanilla, with a cherry of red, white, or green on each) mingled with cryptic ones (anyone for a “Brown Derby”?).

On occasion, the code had a simple, practical purpose. That might be in protecting the privacy of the customer: The name of an order spiked with the laxative magnesium citrate would include Mary Garden “because it makes you sing.” If a customer left without paying, whether by accident or otherwise, it was often easier to shout “95!” than to explain what had happened. “99!” denoted the presence of the big boss or an inspector (soda fountains were notoriously unhygienic and tended not to use soap when washing dishes).

But by the mid-1930s, Bentley observed, the hijinks and fast talk of the soda jerk were already on the wane. Whether or not the audience appreciated it, employers seem to have found the volleying calls of “belch water” and “dog and maggot!” hard to stomach. “Indeed,” he wrote, “the practice is frowned down in many fountains, particularly those owned or operated by large chain organizations or by department stores.”

RTWT