The Epistola de magnete is divided into two parts. Part One (10 chapters): This is a section that serves as a model of inductive reasoning based on definite experiences, and setting forth the fundamental laws of magnetism. He did not discover these laws, but presented them in logical order. Part One discusses the physical (but not the occult) properties of the lodestone and provides the first extant written account of the polarity of magnets. He was thus the first to use the word " pole " in this context. He provides methods for determining the north and south poles of a magnet, and he describes the effects magnets have upon one another, showing that like poles repel each other and unlike poles attract each other. He also treats the attraction of iron by lodestones, the magnetization of iron by lodestones, and the ability to reverse the polarity in such an induced magnet. Peregrinus attributed the Earth's magnetism to the action of celestial poles, rather than to the terrestrial poles of the planet itself.