Matthias Flacius (‘the younger’), Commentariorum physicorum de vita & morte libri IIII, in quibus ea eiusdem argumenti ab Aristotele & Galeno, caeterisque tum philosophis tum medicis breuius sparsim obscuriusve tradita sunt, expediti ori methodo copiosius explicantur ... cum gemino & accurato indice. Frankfurt [Christophorus Corvinus], 1584. [Commentaries on Life and Death, in which the obscure arguments and commentaries of Aristotle and Galen, and other philosophers and physicians, are copiously explained in an easy-to-read method ... with a double and accurate index]. Quarto: [13], 217, [9] pages. FIRST EDITION. In modern boards. Worldcat lists three copies in US: Folger, UMinnesota, and Franklin and Marshall College. The work is not listed at the NLM. A copy is at the Wellcome. This work offers extensive treatments of diet; physical health, hygiene and corpulence; how body ‘heat’ and blood can sustain or imperil health, and the benefits of bloodletting; importance of good air, restful sleep and (the book is addressed to men) regular seminal emissions (I note that some topics are indexed in Greek); and regular bowel movements. The book is carefully organised into sections, chapters, statements and commentaries. The author studied philosophy and then medicine; he was appointed professor of practical medicine at Rostock in 1592. He died at the young age of 46, having not perhaps followed his own advice on achieving longevity. As he was born in what is now Croatia, Flacius has been studied by quite a number of Croatian historians, including the well-known M. Grmek (‘Matthias Flacius Illirycus jun., medicinae doctor et in Rostochiensium academia professor’, Liječnički vjesnik 79 (1947): 394–395; also L. Mohorović, ‘Matija Vlačić Ilirik Mlađi: profesor philosophiae & logicae Aristotelis i profesor praktične medicine’, in M. Miladinov (ed.), Matija Vlačić Ilirik III (2012): 334–342). Some browning and toning due to paper quality, and there has been a small restoration on the marguins of leaves Z4 and c4.