Form and Content

In Microbe Hunters, Paul de Kruif joins together twelve short biographies of thirteen significant individuals in the sciences of bacteriology and immunology. De Kruif directs his attention largely toward the great nineteenth and twentieth century pioneers in the struggle against microbial diseases: Louis Pasteur, Robert Koch, Walter Reed, and Paul Ehrlich. He also takes note, however, of such lesser-known figures as Theobald Smith, David Bruce, Ronald Ross, and Battista Grassi, as well as two prenineteenth century researchers of microbes, the early microscopist Antoni van Leeuwenhoek and the eighteenth century biologist Lazzaro Spallanzani. The book is sparsely illustrated, mainly with portraits.

De Kruif loosely links together his individual narratives in an account of the progress of scientific research against various diseases. Leeuwenhoek, who first observed and described microscopic organisms, and Spallanzani, who discovered how they reproduced, are presented as predecessors who laid the essential empirical ground-work for the scientists of the nineteenth century, beginning with Pasteur. Pasteur took the research process further by definitively joining microbiology and chemistry and by developing distinctive experimental techniques. In the remainder of the volume, each chapter focuses on an individual scientist, but de Kruif’s attention is aimed toward specific diseases—such as anthrax, rabies, and malaria—as much as toward individual researchers.

The sense of inevitable progress in Microbe Hunters is increased by de Kruif’s roughly chronological organization. A discussion of Pasteur’s initial successes leads to an account of the work of Koch, and then the narrative returns to Pasteur’s rabies research, followed closely by the story of Pasteur’s student Émile Roux and Koch’s student Emil Behring and their research on diphtheria. By the end of the nineteenth century, the pace quickens and more diseases come before human scrutiny: Texas fever, sleeping sickness, malaria, yellow fever. Not all the research was equally successful, but, in de Kruif’s schema, all these efforts were steps on the road to ultimate success.

De Kruif’s narrative culminates in the story of Ehrlich, whose “magic bullet”— the chemical 606 or Salvarsan—seemed miraculously to cure syphilis. Even though, as de Kruif admits, Salvarsan had its problems, including acute toxicity in some patients, its discovery forms for him a fitting conclusion to his dramatic tale of discovery.