a list of secrets for healing common illnesses by using certain plants, and with a collection of "magic" recipes. Following De Regimine there are four undated manuscripts dealing with plants and medicine: De Fructibus Tractatus ('Treatise on Fruits') Tractatus de Radicibus Herbarum Diversarum ('Treatise on the Roots of Various Herbs') Tractatus de Herbis ('Treatise on Herbs') and Tractatus de Herbis et Holeribus ('Treatise on Herbs and Vegetables') In these he described the characteristics of various fruits, herbs and vegetables, their regions of origin, the time of their flowering, ways of preparing them and their specific medicinal use. He wrote on the basis of first-hand observation, supported by ancient sources, notably Dioscorides. With financial backing from a supportive bishop, he then studied medicine at the University of Perugia, obtaining his doctor's degree in 1601. During this period, his writing focused on logic, theology and metaphysics. Among the more significant of his works while he studied at university were: Homines et Alia Animalia Prodigiosa Variarum Ignotarum Regionum (Of Humans and Other Animals) (1598), a summary of astronomical knowledge De Planetarum Radiationibus in Singulis Zodiaci Signis (On the Movement of the Planets Through the Signs of the Zodiac) another treatise on astronomy with numerous diagrams drawn by himself a treatise on apoplexy a treatise on angina pectoris entitled De Syncope (On Fainting) Cura Coelestis quae Inferorum Appellatur (Heavenly Care), written for doctors and for all who 'love philosophy' Super Plinii II Historias Naturales, a commentary on Pliny's 'Natural History', extended in scope beyond the original, with the ambitious subtitle 'Liber de Mirabilibus Creaturarum Dei' (Book of the Marvels of God's Creation'). In this work, van Heeck dealt with a number of contemporary concerns of natural science, such as geocentric theory and other Copernican views, against which he argued strongly. He practised as a doctor first in Maenza and then in Scandriglia in the province of Rieti, part of the domain of Duke Giovanni Antonio Orsini. In the course of his medical work, van Heeck became involved in a strange dispute. He treated his patients, who were mostly poor, with great zeal, using simple herbal medicines. For this reason he came into conflict with the apothecary of Scandriglia, one Casolini Ranieri, who made his living selling medicines with exotic names, more magical than scientific. Ranieri conceived a firm hatred of the foreign doctor, whose work threatened to ruin his lucrative business. One night Ranieri