GIOVANNI ALFONSO BORELLI, the head of what has been called the iatro-mathematical sect, or that which, misled by the great progress which the application of mathematics had produced in the physical sciences, attempted to secure the same advantage for medicine, by subjecting to calculation the phenomena of the living economy. He was born at Naples, January 28, 1608, taught mathematics for some time at Pisa, and seems afterwards to have held the professorship of medicine at Florence. He was greatly favoured by the princes of the house of Medici ; but having been engaged in the revolt of Messina, he was obliged to retire to Rome, where he spent the remainder of his life under the protection of Christina, queen of Sweden, who honoured him with her friendship, and by her liberality softened the rigour of his fortune. He died of pleurisy on the 31st December 1679. Borelli, more judicious than Bellini, restricted the application of his system chiefly to muscular motions, or to those phenomena of the animal economy which are in certain points subject to the laws of mechanics, and was led to the discovery of some principles new in themselves, and directly opposed to the received beliefs of his time. His followers, less cautious, wishing to generalize the application he had made, by hypotheses, to which the return to a sound medical philosophy has done justice, greatly retarded the restoration of the science.

The works of Borelli are:—1. Delia Causa delle Febri maligni, Pisa, 1658, 4to; 2. De Renum usu Judicium, Strasburg, 1664, 8vo; 3. Éuclides Mestitutus, 1628, 4to ; 4. Apollonii Pergami Conicorum libri v. vi. et vii., Florence, 1661 ; 5. Theorioe Mediceorum Planetarum ex Causis Physicis deductce, Florence, 1666, 4to ; 6. Traetatus de Vi Pcrcussionis, Bologna, 1667, 4to; 7. Historia et Meteorologia incenda JEtknei, Reggio, 1669, 4to ; 8. De Motionibus naturalibus a gravitate pendentibus, Bologna, 1670, 4to ; and 9. De Motu Animailum, opus posthumum, Rome, 1680, 1681, 4to.