Rats, Lice, and History by Hans Zinsser

First published: 1935

Subjects: Health and illness, nature, and science

Type of work: History

Time of work: From antiquity to the 1930’s

Recommended Ages: 15-18

Locale: Worldwide

Principal Personages:

• Typhus fever, a disease second only to bubonic plague in the deadliness of its epidemics, referred to variously as tabardillo, febris petechialis, jayl fever, ship fever, and famine fever, among other names
• The common louse (Pediculus humanus), a parasite of human beings and a known host of the virus that causes typhus
• The black rat (Rattus rattus), a known host of both bubonic plague and typhus

Form and Content

The chief protagonist of this pseudo-biography—subtitled Being a Study in Biography, Which, After Twelve Preliminary Chapters Indispensable for the Preparation of the Lay Reader, Deals with the Life History of Typhus Fever—is a deadly disease against which humans have struggled helplessly for centuries. Supporting roles are played by familiar enemies such as smallpox, bubonic plague, tuberculosis, and influenza, as well as by historical curiosities such as the mysterious English sweating fever. Several classes of people are pitted against these inhuman foes: early medical historians who observed the ravages of diseases at first hand and recorded descriptions of what they could not understand or control; scientific researchers who gradually tracked diseases to their hiding places in insects and rodents, accumulating knowledge sometimes at the cost of their own lives; and untold millions of victims.

Hans Zinsser begins Rats, Lice, and History by exploring such issues as the theory and practice of biographical writing in his day and the relationship between art and science in order to prepare the way for his own biography of the life cycle of a disease organism and the history of its impact on human affairs. He views typhus fever as a “protoplasmic continuity” and generally avoids anthropomorphism except for the sake of dry, tongue-in-cheek humor. After a short, digressive chapter critical of modernist poetry, he reviews the necessary background information on parasitism, disease-causing bacteria and viruses, and evolutionary adaptation in two further chapters, generally displaying a broad erudition that extends far beyond the medical field. He digresses again with a lengthy history of infectious disease, devoting two chapters to the ancient world and one to more recent military history, concluding that infectious diseases are more important than generals in determining the victor in wars. The common louse requires two chapters, since it is an alternative host of the virus that causes typhus and a vector for transmitting the disease to humans. Rats, mice, and fleas share a single chapter; they are important because they harbor the epidemic form of typhus that is capable of routing armies and toppling empires.

After Zinsser has explained the role played by rats and lice in shaping the course of human history, he introduces the actual subject of his biography, typhus fever, in chapter 12 and describes every aspect of its existence in the last five chapters of the book. The thorough background provided by the earlier chapters makes this examination highly accessible: The reader is by now familiar with the key episodes in the history of epidemics, with the importance of insect and rodent population demographics, and with the subtle transformations of which disease organisms are capable through evolutionary adaptation. The significance of Zinsser’s own research to distinguish the endemic strain of typhus (passed from human to human by lice) from the epidemic strain (passed from rats to humans by fleas) becomes apparent: Thanks to this knowledge of its complete life cycle, the disease can be controlled and humans are no longer at its mercy.

Critical Context

At the midpoint of chapter 13, more than two hundred pages into the book, Hans Zinsser admits that he has been following the model provided by Laurence Sterne’s rambling eighteenth century novel The Life and Opinions of Tristram Shandy (1759-1767). Only at that late point does he bring his main subject into sharp focus. His biography of typhus, like the novel that inspired him, is filled with digressions, examinations and reexaminations of evidence, blind alleys, witty asides, and a small amount of slightly cranky literary criticism that finds fault with modernist writers such as T. S. Eliot, Gertrude Stein, and James Joyce.

Rats, Lice, and History is admired by scientists who are concerned about overspecialization and the public’s misperception of them as number-crunching drudges. Zinsser shows that scientists are intellectuals. He himself was nearing the end of a distinguished career as a scientist: He had held teaching posts at Columbia, Stanford, and Harvard universities; had conducted research on allergies and rheumatic fever in addition to his work on typhus; and had published two textbooks that became classics in their field, Textbook of Bacteriology (1911) and Infection and Resistance (1915). In Rats, Lice, and History, Zinsser shows his readers a different side of science by interlacing his review of medical history with erudite comments on politics, literature, and economics. He speaks from the point of view of a well-rounded humanist rather than that of a scientific specialist.