HISTORY OF MEDICINE
Practical measures: AD 1752-1785
The middle years of the 18th century are notable for practical advances in medicine, based on close observation by working practitioners. Some of those who record their experiences are at the academic end of the medical profession, others are country doctors paying attention to detail. Their efforts raise the scientific standards of medicine and introduce techniques and drugs of lasting benefit.
An early example is William Smellie, the first obstetrician to make a scientific study of the physical process of childbirth.
From 1741 Smellie gives midwives and medical students in London unprecedented practical lectures on childbirth. He achieves this by offering his services to poor women on condition that his students may attend the birth. In this way he is able to develop a scientific account of the mechanism of labour, describing previously unobserved details – such as how the child’s head is adapted for the passage through the pelvic canal.
Smellie publishes his findings in the three-volume Treatises on the Theory and Practice of Midwifery (1752-64). His text provides a new scientific basis for the ancient skills of the midwife.
A similarly thorough groundwork is provided for pathology in a book of 1761. Its author, Giovanni Battista Morgagni, is seventy-nine at the time of publication. He has spent nearly five decades as professor of anatomy at Padua (a post once occupied by Vesalius). During that time Morgagni has kept detailed notes of his dissections of corpses.
This is not new in itself, for there have by now been many published accounts of post-mortem examinations. Morgagni’s originality lies in his related notes, describing the symptoms of his patients before they died.
Morgagni’s book is De Sedibus et Causis Morborum per Anatomen Indagatis (On the Seats and Causes of Diseases, investigated by Anatomy). It describes 640 post-mortems with the related clinical records. Symptoms from now on can be interpreted as external signs of known internal conditions.
In the year of Morgagni’s publication, 1761, a book comes out in Vienna offering the general practitioner a useful new technique in the analysis of a patient’s internal condition. It is the work of Leopold Auenbrugger, an Austrian physician employed in a military hospital. Many of his patients have fluid in the chest. To discover how much, he adapts a technique learnt in his childhood.
As a boy Auenbrugger worked in his father’s tavern and learnt how to judge the amount of wine in a barrel by tapping on its top. He now finds that the same technique works well on a patient’s chest. Auenbrugger has stumbled upon the basic diagnostic technique known as percussion. He describes his findings in 1761 in Novum Inventum (New Invention).
Auenbrugger’s process is disregarded at first by the medical profession. It becomes of more evident use after an invention of half a century later – that of the stethoscope.
Two important developments later in the 18th century are the result of intelligent observation by general practitioners in England. William Withering notices that his country patients use an extract of herbs to alleviate dropsy. By experiment he establishes that the active ingredient is the foxglove. In his Account of the Foxglove (1785) Withering gives clinical details of how to prescribe extract of foxglove, or digitalis, in the treatment of dropsy and hints that it may be of use for heart disease (for which it remains an important drug to this day).
An even more dramatic result of country observations is achieved in the following decade by Edward Jenner.
Jenner and vaccination: AD 1796-1798
Working as a country doctor in the Gloucestershire village of Berkeley, Edward Jenner is aware of a local theory that people who have suffered a mild form of pox – caught from the infected udders of cows – never catch the much more dangerous smallpox.
Cowpox is a relatively rare disease, unrecognized at the time by the medical profession, and it is not until 1796 that Jenner has an opportunity to test this theory of immunity. In that year a dairymaid develops the symptoms. Jenner takes material from an eruption on her hand and (using a thorn) inoculates an 8-year-old boy, James Phipps, with the substance. Phipps develops cowpox and soon recovers.
The principle of inoculation has become well established since the efforts of Lady Mary Wortley Montagu to encourage the use of infected matter from smallpox victims as a preventive measure. Six weeks after the cowpox inoculation, Jenner gives James Phipps a conventional smallpox inoculation. The expectation would be that he develops a mild attack of smallpox, survives it and becomes immune. In the event, as Jenner hopes, Phipps shows no sign at all of being infected by the smallpox virus.
Continuing his experiments, Jenner proves that even in a long line of inoculation from person to person cowpox still confers immunity.
Jenner publishes his findings in 1798 in the splendidly titled An Inquiry into the Causes and Effects of the Variolae Vaccinae, a disease discovered in some of the Western Counties of England, particularly Gloucestershire, and known by the name of Cow Pox.
Variolae Vaccinae, meaning literally ‘smallpox of cows’, is Jenner’s scholarly name for cowpox. The phrase soon provides the word vaccination (initially coined in France as a term of mockery) for this new form of inoculation against smallpox. After some initial opposition from the medical establishment, vaccination proves its merits and the use of it rapidly spreads. As early as 1807 it is made compulsory in Bavaria (though not till 1853 in Britain).
In 1806 the president of the USA, Thomas Jefferson, writes to Jenner: ‘Future generations will know by history only that the loathsome smallpox existed and by you has been extirpated.’ He is right, but the process takes longer than the president probably expects – even though the immediate effects are impressive. In Britain the annual death rate from smallpox falls during the 19th century from about 2000 per million to well under 100. But diseases are difficult to extirpate on a worldwide basis.
Nevertheless smallpox is the first disease with which that aim is eventually achieved. After intensive international vaccination programmes, there is by 1980 no case of smallpox on the planet.
