If her legacy as a chef, television personality, and all around delightful human being weren’t enough to solidify Julia Child as one of the coolest people who ever lived, here’s another awesome resume-builder: she made shark repellent.

It was 1943, World War II was raging, and a 31-year-old Child (then McWilliams) was working for the Emergency Rescue Equipment Special Projects department of the Office of Strategic Services, the predecessor to the CIA. Combat increasingly took place on water, and the organization hoped to not just prevent shark attacks, but also bites from barracudas and piranhas. The ERE department—including Child—was tasked with whipping up a concoction that could do just that.

According to documents recently released by the CIA, the organization had been looking for a solution since July 1942—just a month after the OSS was created—and tested over 100 substances in their search, including common poisons as well as "extracts from decayed shark meat, organic acids, and several copper salts, including copper sulphate, and copper acetate."

Copper acetate proved to be the most promising; tests on bait showed that it was "60 percent effective in deterring shark bites," according to the CIA. It was mixed with black dye into a disk-shaped “cake” that could be affixed to the body in a number of ways and would smell like a dead shark when released in the water, lasting 6 to 7 hours.

But the repellent apparently tested poorly with barracudas and piranhas, and, in a December 1943 memo to the Navy Research Department, Edward Howell, Chief of the Bureau of Aeronautics, wrote that though the cake was slightly effective against small sharks, the Bureau thought “that it is illogical to expect that such effect as was shown in normal feeding behavior would give any promise of affecting the voracious behavior of the few species known to have attacked man.”

Despite its dubious effectiveness, the Army and the Coast Guard wanted to use the repellent—which, they reasoned, could potentially deter bites and would go a long way to improving the morale of people who could potentially be attacked—and it stuck around for another 25 years.

[h/t io9]