Category Archives: The Scientific Revolution

Variolation: Immunity to Smallpox



Lady Mary Wortley Montagu (1689–1762)

Small pox was one of the most common infectious diseases that killed thousands in recurring epidemics. It can be traced as far back as ancient Egypt and in various outbreaks it regularly killed off large numbers of people. By the 17th Century it had recurred in many societies. Thomas Sydenham believed that small pox was best understood as a disease of passage: once you got it and survived there was no chance of getting it again. We are startled at his equanimity because there were such high mortality rates. Apparently in the 17th seventeenth and throughout the eighteenth centuries, about 60% of the population got small pox and 20% died of it: death was a much greater spectre in daily life than it is today. One of the disadvantages of living in cities was that infectious diseases spread more quickly in them, and one of the advantages was that if you survived them your immunity increased. In the Americas and Australia after the arrival of Europeans, mainly small pox, but other diseases such as measles killed many millions of indigenous people who had had no previous contact and hence little immunity to the diseases. In some cases 90% of a particular population died.

Lady Mary Wortley Montagu was the wife of the British ambassador to the Ottoman Empire and saw how the Turks inoculated people to cause a mild form of smallpox and produce immunity to the disease. The procedure was called “variolation” and was performed by rubbing powdered small pox scabs on a superficial scratch, or injecting fluid from a small pox pustule. This method had ancient roots. Lady Wortley-Montagu contracted smallpox in 1715 and bore its scars. She had her son Edward variolated in Turkey and then when she returned to England and a smallpox epidemic started in 1721 she asked her doctor, Charles Maitland, to variolate her young daughter. Maitland tested the procedure by variolating six prisoners and infecting them with this mild version of smallpox. None of them later contracted small pox. We must assume that they were in one way or another exposed to it.

Variolation was taken up by royal families across Europe but it did not spread to the general public. Lady Mary is one of the very few women mentioned in most medical histories. But despite the introduction of variolation, there was still very little understanding of the nature of infectious diseases.  Variolation was not an entirely safe procedure because one did contract a mild version of small pox: about one in every hundred people who were variolated died of the disease – a much lower percentage than the 20% who died of small pox.



Medicine in the 17th Century, Cont’d


Johann Baptista van Helmont (1579-1644)

Paracelsus was the primary influence on this Belgian physician-alchemist. Van Helmont was a Paracelsian who used chemical medicines and had a strong interest in alchemy, but revised and elaborated many of Paracelsus’ positions including the nature and number of elements and his explanation of disease. His experimental work included attempts to show that water was an even more basic constituent of matter than Paracelsus’ three philosophical principles of sulfur, mercury and salt. In one famous experiment he planted a willow seed in 100 kilograms of earth, added only water for several years and found that the tree now weighed 75 kilograms while the weight of the earth did not significantly change. Van Helmont denied the explanatory value of Aristotelian final causes but believed something quite similar. The seed contained an archeus, a kind of spirit that could transmute water into willow. He held that there were many different kinds of archei each functioning in this seed-like way. In the body they transmuted food into blood through a process of digestion or fermentation. As external agents archei could enter the body to cause disease by a process of putrefaction. Much of van Helmont’s experimental laboratory work reduced various substances to discover the gases that contained their archei and to produce medicines to counteract their effects.

Van Helmont’s search for the Philosopher’s Stone was an attempt to find the ultimate seed, one that would transmute base metals into gold, but more importantly would function as a panacea by finding a spirit that could cure all ills. His methods, like those of Paracelsus were dependent on mystical visions as well as laboratory experiments. A step toward finding the Philosopher’s Stone was the chemical formation of the alkahest, a kind of counter Philosopher’s stone which was a universal solvent that could ferment or digest material into its basic (lowest) constituents.

Paracelsus, through van Helmont had a growing number of followers in England who were especially interested in iatrochemistry and alchemy, including George Thomson (1617-1677) and the young American George Starkey (1628-1665).


(c) Royal College of Physicians, London; Supplied by The Public Catalogue Foundation

Baldwin Haney (1600-1676)

By the middle of the 17th century, the views of Galen, Paracelsus and Descartes had all become part of the then current understanding of medicine and the human body. However academic physicians continued to be trained as Galenists and they dominated the medical schools, the Royal College of Physicians and were the practitioners to the wealthy. Baldwin Haney (1600-1676) whose wonderful portrait is by Anthony van Dyck is an excellent example of the wealthy physicians who were members of the College.

William_PettyThomas_WillisAnne Greene

William Petty (1623-1687)Thomas Willis (1621-1675) Anne Greene (1628-1665).

In the famous case of Anne Greene, Thomas Willis, William Petty and some medical students who were studying anatomy with them,  revived her after she had been hung for the murder of her illegitimate child (a crime she did not commit). Her body was given to them for dissection, but as they prepared her, they found that she was still breathing. They used humoral techniques to revive her: they poured hot cordial down her (cold) throat, bled her, rubbed her limbs and applied hot plasters.

As we have seen, the three academic medical influences at the time came from Galen, Paracelsus and Descartes. Each was accompanied by a metaphorical picture of health which retains some currency today. The first saw health as a good balance among the humours, the second as appropriate chemical composition, and the third as a smooth running machine. Regardless of their primary orientation many physicians had absorbed and included aspects of each of these three positions, and most employed remedies that were a mixture of all three. The complexity surrounding their ideas about health derived from the intermingling of these different ways of thinking. The theoretical differences among the academic physicians meant little to the vast majority who could not afford expensive doctors.