The Sceptical Chymist: or Chymico-Physical Doubts & Paradoxes is the title of a book by Robert Boyle, published in London in 1661. In the form of a dialogue, the Sceptical Chymist presented Boyle's hypothesis that matter consisted of atoms and clusters of atoms in motion and that every phenomenon was the result of collisions of particles in motion. For these reasons Robert Boyle has been called the founder of modern chemistry by J. R. Partington. Boyle first argued that fire is not a universal and sufficient analyzer of dividing all bodies into their elements, contrary to Jean Beguin and Joseph Duchesne. To prove this he turned for support to Jan Baptist van Helmont whose Alkahest was reputed to be a universal analyzer.