Quick: How many nuclear warheads had been detonated above-ground by 1963?

If your answer was somewhere just north of two, I wouldn’t blame you. I wasn’t yet born then myself, and the idea of nuclear bombs exploding above Nevada is hard to fathom. The answer, I learned in the opening chapter of William Souder’s new biography of Rachel Carson, is more than 500. The United States was responsible for about 200 of those.

The story of Carson’s life is the story of an era that is quite recent but also strangely distant from our own, in which the twin threats of nuclear fallout and chemical use were the subject of national debate. Souder makes this plain in the book’s opening scene, with a reporter asking President John F. Kennedy about the growing concern over the use of the pesticide DDT. He responded that his administration was looking into it, “particularly, of course, since Miss Carson’s book.”

The scene highlights an equally remarkable aspect of the times in which Carson lived. A woman could write a book about the dangers posed by a new generation of pesticides, and that book — made popular in part because of a three-part serialization in the New Yorker before publication — would be so widely read and debated that the president didn’t even have to mention its title, “Silent Spring.”Everyone was talking about Miss Carson’s book. It is hard to envision, in today’s crowded media landscape, any book capturing the nation’s attention in the same way.

This is the great strength of “On a Farther Shore.” Without overstating the point, Souder draws a portrait of cultural and political life in the middle of the 20th century and places Carson squarely at the center of it. Imagine: In 1951, a little-known field biologist publishes a poetic and immaculately researched account of oceans and the life they contain, employing a narrative that begins more than 2 billion years ago, encompasses the birth of the moon and proceeds straight through to modern times, and “The Sea Around Us” rises to the top of the bestseller list and sits there for 39 weeks.

"On a Farther Shore: The Life and Legacy of Rachel Carson" by William Souder (Crown)

It was a different time for science and a different time for science writers. Today’s writers might cheer as they read about Carson coolly declining her publisher’s requests that she give interviews and attend book signings: Such distractions would be shortsighted, “as her work could go forward only if she could maintain her life as it had been before The Sea Around Us.” If blogging for the Huffington Post and maintaining a Twitter account had also been among her publisher’s expectations, would “Silent Spring” have been written at all?

Souder makes it clear that Carson had enough distractions as it was. She’d worked as a government biologist and writer from 1936 until 1952, when sales of her book allowed her to quit her job and write full time. She bought a plot of land near Boothbay Harbor, Maine, and had a summer cottage built on it. It was there that she met her neighbors, Stan and Dorothy Freeman, and began a romantic relationship with Dorothy Freeman that lasted the rest of Carson’s life.

The women’s letters were unambiguously passionate: In 1954, Carson wrote to Freeman, “But oh darling, I want to be with you so terribly that it hurts!” While her husband napped, Freeman wrote a letter from another bedroom in her house, telling Carson that she was writing from “the corner that belongs in my heart only to you — you know where and why.” One Christmas they shared a hotel room in New York, and the letters leading up to that rendezvous were concerned with whether Carson should register under an alias and whether the women would be able to “restrain themselves long enough to get up to their room,” to use Souder’s paraphrasing.

In spite of the heated language, Souder suggests that sex “seems not to have been part of their relationship, or at least not an essential feature of it,” and that their feelings for each other “existed in a realm above ordinary physical love and desire.” (If someone has done a study of the number of “romantic friendships” between women that biographers assume to be platonic, as compared with similar friendships between men, I’d like to know about it. I hope such women were far less prim than their biographers assume.)

Freeman was not her only distraction. As Carson began work on her book on pesticides in 1958, her mother, with whom she’d been living in Silver Spring, Md., died. This left Carson as the sole caregiver for her young great-nephew, Roger, whose own mother — Carson’s niece — had also died recently. Carson’s work was further slowed by her determination to demonstrate a link between pesticides and cancer, something that was not easy to prove at the time. In 1960, as she was pursuing this question, she discovered two masses in her left breast and began a battle against cancer that lasted until her death, four years later, at the age of 56.

The irony of writing about cancer while she was ill from it, and of undergoing radiation treatment as she was drawing parallels between the dangers of radioactive fallout and massive DDT spraying, was not lost on her. She kept her illness a secret from all but her closest friends, fearing that disclosure would give her critics ammunition to question her motivation in writing the book.

Even the cancer’s progression and her efforts to continue working in spite of it conjure up the times in which she lived. She learned, too late, that doctors hadn’t told her the truth about her initial diagnosis, perhaps believing that she wasn’t capable of making informed decisions about her treatment. And even as the cancer recurred, she managed an extraordinary volume of daily correspondence with scientists whose research might support the idea that pesticides were carcinogenic. It is difficult for today’s writers to imagine themselves conducting their research by post, sending letters into a vast unknowable world in which a biologist out West might know something about the effect of herbicides on cattle, or a Mayo Clinic physician might have ideas about the connection between leukemia and pesticides.

Carson didn’t finish navigating these challenges until 1962, when at last she published “Silent Spring,” setting off an extraordinary national debate. “On a Farther Shore” ends as it begins — with Kennedy working toward an end to nuclear testing and contemplating the dangers of pesticides. Carson didn’t live long enough to see the ban on DDT that resulted from her work (and she actually never advocated a total ban), but in Souder’s telling she was a quintessential woman of her time, juggling the demands of a family, a complicated love affair, an illness and a high-profile career, and somehow managing to sit down in the center of it and get her work done.

Amy Stewart is the author of “Wicked Bugs: The Louse That Conquered Napoleon’s Army and Other Diabolical Insects.”


The Life and Legacy of Rachel Carson

By William Souder

Crown. 496 pp. $30