John Pechey (1654-1718), commenting on acute diseases, pointed to the many problems associated with treatment of fevers in early modern Europe. First and foremost was the question of the correct identification of the disease: was the physician dealing with a pestilential fever or plague? If the epidemic was to be defined as a fever, what type of fever was it? Was it something that had been effectively dealt with before or was it a new form of disease? The constantly changing epidemiological landscape ensured that many of Worth’s texts dealing with fever present the reader with a chronological survey of the rise and fall of fevers in early modern Europe.
One of the principal challenges was to identify exactly what type of fever one was trying to cure. This detail, from Francesco Maria Torti’s Therapeutice specialis ad febres (Modena, 1712), shows us a section of his Fever Tree (which may be seen in its entirety on the Home Page of this website). In this section we can see the principal divisions of fevers in primary, secondary, tertian and quartan but, as Sir Richard Blackmore’s discussion of the causes of fevers tells us, there were a host of other names that might be used in different circumstances:
Francesco Torti, Therapeutice specialis ad febres (Modena, 1712), foldout plate of fevers.
The difficulty in defining fevers was matched by a lack of a strong theoretical underpinning. As Smith (1981a) has pointed out, Hippocrates (and his Alexandrian commentators) had indeed written concerning fevers but many of their comments were only implicit in such works as the Epidemics 5 and 7 and had not been the specific focus of such discussions. Bile was associated as a cause as were climatic conditions, and the patient was cured by a combination of nursing and purging in order to restore the balance of the humour. As Lonie (1981) has explained, this approach continued well into the medieval and indeed early modern period. Medieval writers such as Avicenna (whose works were likewise collected by Worth), had defined fever as ‘extraneous heat, kindled in the heart, from which it is diffused to the whole body through the arteries and veins, by means of the spirit and the blood, reaching a heat in the body itself which is sufficient to injure the natural functions’ and since his works formed an important part of the medieval and early modern medical curriculum, this was the accepted definition of fever. The debate therefore centred on the topic of how the physician could expunge this ‘preternatural’ heat from the patient. Some, such as the famous sixteenth-century French physician Jean Fernel (1497-1558) and his follower, Oratio Augenio, (both writers collected by Worth), sought to extend their understanding of the causes of individual types of fever, such as ‘intermittent fevers’. Seventeenth- and early eighteenth-century writers were faced with the challenge of explaining fevers in the light of William Harvey’s theory of the circulation of the blood and, influenced by cartesian and Newtonian thought, produced mechanistic and physical theories concerning the role of the blood, heart and heat in the body – rather than concentrating on cures. It was left to physicians such as Thomas Sydenham to investigate the nature of individual fevers and suggest treatments.