The ‘Microbe Hunters’ Go to School

Lately there has been quite a lot of discussion about the move away from textbook learning—who knows how much longer that epithet will hold recognizable meaning. A 2024 report from the American Historical Society, for instance, found that U.S. teachers are “replacing textbooks with the internet” due to an increasing reliance on educational technologies and the availability of free, open-source materials.

While the technologies involved are fairly new (e.g. electronic platforms for course delivery and program assessment), the impulse to repurpose informal educational materials for classroom instruction is not. We have a nice example of this openness to reuse in the Othmer Library’s collection of Paul de Kruif’s bestseller, Microbe Hunters, a “rumbustious” work of collective biography that has been in continuous publication since 1926.

De Kruif (1890–1971) was a microbiologist who was no stranger to personal controversy. John Steinbeck once described him as a man in “a constant state of emergency.” An army physician, he briefly held research positions at the University of Michigan and with the Rockefeller Institute for Medical Research. He first turned to popular science writing around 1918 as a means of paying for his complicated love life: de Kruif decided to divorce his first wife, with whom he had two children, in order to marry Elizabeth Barbarian, an assistant in his laboratory, which meant coming up with the money to support two households.

After he was fired from the Rockefeller Institute for publishing satirical portraits of his supervisors in 1922, science writing became his sole means of support and professional activity. Microbe Hunters (1926), which championed the efforts of microbiologists from Antoine van Leeuwenhoek to Walter Reed and Paul Ehrlich, was an immediate success, inspiring generations of curious youth to careers in biology, pharmacology, and public health.

Our newest outdoor exhibition, Sensational Science: A Century of Microbe Hunters, documents the book’s impact on informal learners through testimonials from our oral history collection. The exhibition also features dust jackets and covers from different editions that are as sensational as de Kruif’s prose.

One 1932 edition, sporting a rather plain navy cover, did not make it onto our building’s façade. Though visually unremarkable, this “special edition” offers a fascinating window onto U.S. science education during the interwar period. It was edited and abridged by Harry Greenwood Grover with “the needs of both students and teachers” in mind.

Grover, otherwise known for preparing student editions of literary and theatrical works, had quite a lot to say in his foreword about the state of U.S. education during the 1930s. “[T]he material in the book is of genuine value to students in the twentieth century,” he wrote. “It connects the past, from which the microscope has freed man, to the present, in which it is protecting him. The book is good history, and it is history peculiarly significant to the youth of today because it is a history of the advance of one kind of tremendously important science.” Grover concluded: “[I]t is a thrilling recital of a series of battles told as if they were battles, not as if they were merely experiments.”

Anticipating the concern that such flair might be seen to compromise scientific objectivity, Grover went on to defend the importance of literary studies for students of science. He wrote:

We can meaningfully compare Grover’s advice to recent initiatives that defend the humanities as a tool of “information literacy” using language that is friendly—not opposed—to STEM.

If Grover addressed himself primarily to teachers, de Kruif wanted to say something directly to their students. In his preface to Grover’s 1932 edition, he wrote:

We might conclude from this that de Kruif’s main objective was similar to our own here at the Institute—to “tell the stories behind the science.” But Grover had to build a bridge from that informal learning goal to the needs of formal educators. Though he left de Kruif’s prose mostly untouched, Grover added footnote explainers where he felt U.S. highschoolers might need a bit of extra support or context. These include guides to pronunciation, definitions of Latin terms, biographical sketches of people mentioned in passing, and etymological notes on words like “shambles,” which originally referred to a “slaughter house; a place where butchers kill animals for meat.”