Microbe Hunters

We have had many books of late about the discoveries of science but few like this one. The popular expositor has been slow to grasp the significant distinction between a mystery story and a detective story. It was Poe, I believe, who first among writers of fiction gave new life to the story of crime by turning the reader’s attention toward the unravelling of the mystery instead of presenting him with a rather silly puzzle for his own guessing. It is this distinction which Dr. de Kruif has grasped in his story of the war against infectious diseases. We follow each conquest in the company of the chief actor—a vividly conceived personality, blundering, passionate, human—and his triumph becomes our triumph. Leeuwen-hoek, Spallanzani, Metchnikoff, Ehrlich—these are no puppets moved by the strings of circumstance, but living men who seem almost by their faith alone to have made real the world of their imagining. The story of medicine is perhaps more than usually suited to this dramatic treatment, for there is something godlike in man’s rebellion against the fact of disease, but what Dr. de Kruif has here accomplished for his own specialty might well be imitated by workers in other scientific fields.

This is not to say that the thing is supremely well done. There is in the style too much straining after effect, and a distinct cheapening of the theme by the author’s mistaken effort after picturesqueness. But in spite of this “Microbe Hunters” is a book after the scientist’s own heart—a book which comes nearer to a true account of what science really is than all the fairy tales ever written about the marvels of nature for a generation that demands signs and wonders. For whether Science be the goddess we think her, or the harlot that the early church deemed her, it is in the passionate devotion of her followers that her nature is made manifest. And what a diversity these characters reveal. Leeu-wenhoek the Dutch shop-keeper, insatiably curious, incor-ruptibly honest, but guarding like a miser the secret of making his microscopes. Spallanzani, free-thinking priest and therefore hypocrite by all accepted standards, crafty, pugnacious, and jealous of others, but saved within his twisted soul by some daemon from the scientist’s unforgivable sin of self-deception. Pasteur the incomparable genius, the pathfinder. Koch, the sure-footed. Metchnikoff the incredible bundle of contradictions. David Bruce the fighter. Roux, Behring, Ronald Ross, Grassi, our own Theobald Smith and Walter Reed—these and a number of others live again in these pages. That which stands out above all in Dr. de Kruif’s story, and which distinguishes it from conventional accounts of science is his understanding of the real nature of scientific discovery. Instead of the usual picture of observation, induction and deduction with which the public is familiar, he shows our progress to have consisted often in a series of magnificent divinations, verified later by the slow toil of experiment. Experiment is not so much the road to discovery as the investigator’s code of morals—the appeal from Philip drunk with the intoxication of an insight almost mystical to the sober, coldly critical Philip. It must be true!—but—is it? Pasteur is seen to be lacking somewhat in this power of detached criticism. He turns out to be right, indeed, but he is satisfied with proofs that are not proofs. Koch was the lesser genius, but it was Koch who first developed the technique of proof, and who gave to all later bacteriologists the modes of the experimental syllogism by which certainty could be assured. Pasteur could indeed inspire and dazzle men by the swift flights of his genius, but he had no real pupils, because that which can alone be taught—method—was not his to teach. Later investigators may have been followers of Pasteur, but they were essentially pupils of Koch. It was Grassi who completed the proof of Ronald Ross’s thesis by showing that malaria is conveyed to human beings by the bite of an infected mosquito, and only in this way; and though Grassi upset Robert Koch’s hypothesis by this work, he showed himself his master’s true pupil.

The scientific man can read between the lines, and he naturally wonders how much sympathetic understanding of these characters the layman will achieve. The weaknesses, the passion, the vanities—all the frustrations of the inner striving by the warped individualities, are set forth here unsparingly. We see Walter Reed animated apparently by a high dream of human welfare; we see others moved by a sordid desire to outshine a contemporary, but behind all this is something not explainable in terms of the obvious motive. Why should Spallanzani, having found an experiment which overwhelmingly refuted his critics, Needham and Buffon, turn around and himself devise severer tests than any which had been proposed? He had made the discovery; why should he deliberately try to upset his own work? Again and again we see these men moved by some inner compulsion rather than by any obvious motive to try to destroy the creations of their intellect. This, says Dr. de Kruif, is the nature of that strange thing called science. But who will understand?