06/12/2026
In the late 1940s, while newspapers celebrated the rebuilding of a post-war world, two scientists were conducting their own quiet revolution—one that would reshape medicine using nothing more than soil samples and postage stamps.
There was Rachel Fuller Brown, a chemist in Albany, New York, and Elizabeth Lee Hazen, a microbiologist in New York City. Two brilliant women working in two separate laboratories. Their extraordinary partnership was conducted almost entirely through the mail.
Their mission seemed almost absurdly simple: find something in ordinary dirt that could fight fungal infections. While bacterial infections could be treated with penicillin and other new antibiotics, medicine had no safe, effective answer for fungal diseases. At the time, systemic fungal infections were often a death sentence.
Their method was as humble as it was ingenious. Elizabeth would collect soil samples from farmers' fields, backyard gardens, and friends across the country. Because each sample potentially contained millions of microorganisms, any one of them might hold the key. She would carefully package the dirt and mail it to Rachel in Albany.
From there, Rachel would begin the painstaking work of isolating microbes from each sample and testing them methodically. She searched endlessly for an organism that could kill fungal cells without harming human cells. Sample after sample, test after test, month after month, most yielded nothing. Still, they kept going.
Then, in 1950, a soil sample Elizabeth had collected on a friend's farm in Virginia yielded a massive breakthrough. A microorganism called Streptomyces noursei produced a compound that did exactly what they had been searching for—it destroyed fungal cells while leaving human cells completely unharmed. They named it nystatin, in honor of the New York State Department of Health, which had supported their work.
Nystatin became the world's first safe and effective antifungal antibiotic for humans. It cured thrush in infants—a painful fungal infection that left babies unable to eat. It treated common ailments like athlete's foot and ringworm. Most critically, it saved lives by treating severe systemic fungal infections that had previously been untreatable, especially in patients with weakened immune systems.
But nystatin's impact extended far beyond human medicine. Art conservators discovered it could protect priceless paintings, manuscripts, and historical artifacts from mold damage. Museums began using it to preserve works that had survived centuries, only to face destruction from fungal growth. The Sistine Chapel's frescoes, ancient manuscripts, historical documents, and rare books were all protected by a compound discovered in Virginia dirt.
Furthermore, forestry researchers used it to protect tree seedlings, and the pharmaceutical industry built upon their discovery to develop entire generations of new antifungal medications.
By the time the patent expired in 1974, nystatin had generated over $13 million in royalties. Brown and Hazen could have become incredibly wealthy. They had certainly earned it through years of unglamorous work, brilliant scientific insight, and a discovery that saved countless lives.
Instead, they gave it all away.
Every single penny went to establish the Brown-Hazen Fund, specifically designed to support scientific research, with a particular focus on young scientists, women in science, and researchers who lacked access to traditional funding sources. They understood something profound: the next breakthrough might not come from a prestigious university or a heavily funded lab. It might come from someone just like them—someone persistent, curious, and willing to do the slow, humble work that others overlooked. Someone who just needed a chance.
When they won the Squibb Award in Chemotherapy in 1955—one of the highest honors in pharmaceutical research—they were almost surprised anyone was paying attention.
Elizabeth Hazen passed away in 1975, and Rachel Brown followed in 1980. Both lived to see their discovery transform medicine, yet neither ever pursued the wealth or fame that could have been theirs. Two women who never worked in the same room changed the world through envelopes full of dirt. They didn't need accolades; they simply relied on partnership, persistence, and a profound belief that science exists to serve humanity.
Somewhere right now, a baby with thrush is being treated with nystatin, fully able to eat and thrive. Somewhere, a museum conservator is protecting a Renaissance masterpiece from mold. Somewhere, a young scientist is receiving funding from a program built on Brown and Hazen's model of generosity.
In all of those moments, these two women—who chose collaboration over competition, persistence over prestige, and generosity over wealth—are still changing the world. One envelope at a time.