Microbe Hunters by Paul de Kruif

‘Microbe Hunters’, as I have often been told, is a classic reading in microbiology—one of those books that can inspire the beginning of a career. In this book, written in 1926, American microbiologist and author Paul de Kruif proposes to acquaint us with the great pioneers of microbiology, from Leeuwenhoek to Ehrlich, via Pasteur, Koch, Roux and several more. 

I gave it a try, and I must confess that at first I was a bit taken aback by the quite unusual style of the author: extremely enthusiastic, overly lyric, made to immerge us in the life of the protagonists with a plethora of details that may or may not be true.  I can’t remember reading anything quite approaching the surprising and unusual tone of Microbe Hunters. Here’s an example describing Spallanzani’s early experiments (p. 34):

“What’s this?” [Spallanzani] cried. Here and there in the gray field of his lens he made out an animalcule playing and sporting about—these weren’t large microbes, like some he had seen—but they were living little animals just the same.

“Why, they look like little fishes, tiny as ants,” he muttered—and then something dawned on him— “These flasks were sealed- nothing could get into them from the outside, yet here are little beings that have stood a heat of boiling water for several minutes!”

[…] It was a great day for Spallanzani, and though he did not know it, a great day for the world.

But as I was reading further I grew accustomed to this prose, and, to my own surprise, I started to enjoy it! It is indeed difficult not to share de Kruif’s enthusiasm for these great men of the past and, even though I would take the author’s factual accuracy with more than a grain of salt, the book really makes you want to learn more about the personal life of these pioneers.

Notably, the figures of Pasteur and Koch are vividly brought to us, and the comparison of the two is striking (p.147-148):

Nothing is truer than that there is no one orthodox way of hunting microbes, and the differences between the ways Koch and Pasteur went at their work are the best illustrations of this. Koch was as coldly logical as a text-book of geometry—he searched out his bacillus of tuberculosis with systematic experiments, and he thought of all the objections that doubters might make before such doubters knew that there was anything to have doubts about. Koch always recited his failures with just as much and no more enthusiasm than he did his triumphs. There was something inhumanly just and right about him and he looked at his own discoveries as if they had been those of another man of whom he was a little over-critical. But Pasteur! This man was a passionate groper whose head was incessantly inventing right theories and wrong guesses—shooting them out like a display of village fireworks going off bewilderingly by accident.

The great Pasteur, one of the "microbe hunters"(Wikimedia Commons)

De Kruif does a great job at describing the great endeavors accomplished by these men, who were motivated both by scientific curiosity and by societal necessity: in the 19^th century, the toll paid by the human race to contagious diseases was enormous. Because, in important aspects, the story of microbiologists is the story of hunting diseases: anthrax, transmitted by the spores of the bacterium Bacillus anthracis (Koch identified the germ, and Pasteur developed the first vaccine in 1881); rabies, the viral disease also fought by Pasteur; diphtheria, caused by a bacterial toxin; Texas fever, due to a Protozoan that infects cattle via a tick; the sleeping sickness, a Trypanosoma transmitted to humans via the tsetse fly; and malaria, of course, caused by another Protozoan transmitted by a mosquito. 

De Kruif is optimistic (and enthusiastic!) about the power of men of science to fight infectious diseases and thus alleviate the sufferings of mankind. It is worth noting that Microbe Hunters was published two years before what would become the greatest discovery of all times: the discovery of penicillin by Fleming.

I would recommend Microbe Hunters, as long as one accepts its exuberance (or maybe because of it!).

Reference:

• De Kruif, Paul. (1926) Microbe Hunters. Blue Ribbon Books, New York. 365 pages.