Abstract

The change in the physiological conception of body fluid during the Seventeenth Century exemplifies the beginning of changes in chemical ideas away from humours as irreducible components of fluid systems towards water as the common solvent of an indefinitely large range of solutions. Against the Galenic humoral view of body fluids J.-B. van Helmont postulated ‘latex’, a humour distributed through the body and common to several body fluids. The theory of latex explained experimental findings and provided a basis for Helmont's introduction of diuretics into the treatment of dropsy. Francis Glisson adopted the theory of latex. In this paper it is shown that Helmont contradicted, in part at least, the distinctness of humours by a doctrine of a common reservoir from which various body fluids are drawn. It is further argued that, on the available evidence, Helmont is the originator of this idea of a common reservoir. Through hitherto unremarked and unpublished manuscript evidence, it is shown that Glisson, in adopting the theory of latex, and its therapeutic application, modifies and extends it. In the manuscripts Glisson expresses himself in the language of Helmontian philosophy. Given Glisson's known influence , the question arises what part, if any, is attributable to him in the transmission of the doctrine of the common reservoir. From the point of view of experimental science, that doctrine makes a break with the past no less radical than does, say, that of the circulation. It appears that we have here yet another major contribution of Helmont to the scientific revolution with, through Glisson, a possible channel of transmission of this contribution