ABSTRACT
Passageways and organic metaphors have natural affinities. From earliest times the human body has been thought of as a container made up of conduits for conveying blood and humors. Egyptian medicine understood the working of the body by means of the metaphor of the Nile's flooding and receding. 1 One branch of physiological studies in early eighteenth century Britain and on the Continent also defined the body as a structure of tubes and vessels and understood health to be the maintenance of a proper velocity of blood-flow through them. 2 This line of inquiry strongly impressed itself on medical amateurs and remained alive in metaphor after the main current of physiological studies was directed elsewhere.
