The Greatest Benefit to Mankind by Roy Porter

Author:Roy Porter
Language: eng
Format: epub
Publisher: W. W. Norton & Company
Published: 2013-05-01T16:00:00+00:00

CHAPTER XIV

FROM PASTEUR TO PENICILLIN

Just think of it. A hundred years ago there were no bacilli, no ptomaine poisoning, no diphtheria, and no appendicitis. Rabies was but little known, and these we owe to medical science. Even such things as psoriasis and parotitis and trypanosomiasis, which are now household names, were known only to the few, and were quite beyond the reach of the great mass of the people.

STEPHEN B. LEACOCK, Literary Lapses (1910)

MICRO-ORGANISMS

A PATCHWORK OF IDEAS AND INSTITUTIONS, theory and practice, craft and science, involving divided and vying professional factions, medicine has a generally muddled history, infinitely less clear-cut than, say, theoretical physics. But the latter part of the nineteenth century brought one of medicine’s few true revolutions: bacteriology. Seemingly resolving age-old controversies over pathogenesis, a new and immensely powerful aetiological doctrine rapidly established itself – one that its apostles prized as the master-key to disease, even to life itself Moreover, most unusually for medicine, the new disease theories led directly and rapidly to genuinely effective preventive measures and remedies, saving lives on a dramatic scale.

The general thinking behind bacteriology (that disease is due to tiny invasive beings) was far from new; theories of contagion, long proposed for maladies like smallpox and syphilis, maintained that disease entities were passed from the infected party to others; in the case of the pox, sexual intercourse offered the obvious transmission mode. Developing some hints in Galen, Girolamo Fracastoro had written in 1546 of disease seeds (seminaria contagiosa) carried by the wind or communicated by contact with infected objects (fomites); and the microscope confirmed the reality of wriggling, squirming ‘animalcules’. Yet what grounds did anyone have for thinking that such ‘little animals’ caused disease?

Similar problems attended the putrefaction problem. What made substances go bad, decompose and stink? Why did grubs and mites appear on decaying meat and fruit? Did decay produce the insects (by spontaneous generation) or insects the decay?

By boiling up broth, sealing it in containers and showing that nothing happened, Francesco Redi (1626–98) believed he had proved that maggots did not appear on meat protected against flies, thereby discrediting the theory of spontaneous generation; in De la génération des vers dans le corps de l’homme (1699) [On the Generation of Worms in the Human Body], Nicholas Andry also argued that the seeds ‘entered the body from without’. But, as so often, there were counter-findings. In 1748 John Needham (1713–81) repeated Redi’s experiments; he boiled a meat infusion, corked it, reheated it and, on cooling, identified ‘animalcules’ in the broth which, he concluded, had appeared spontaneously. Convinced Needham had failed to protect his infusion from the air, Lazzaro Spallanzani maintained that broth, if boiled and hermetically sealed, would keep indefinitely without generating life. With no agreement as to where these ‘little animals’ came from, their alleged role in disease causation was a mare’s nest.

The crucial issues raised were what such ‘demonstrations’ actually demonstrated (experiments are always open to multiple explanations), and whose experiments should be trusted. There were also metaphysical puzzles. For some, the very idea of ‘spontaneous generation’ smelt of scandal.

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