Descartes: Striated particles (particulae striatae) pass veins inside the earth in two senses.
Tuesday, October 11th, 2011René Descartes (1596-1650), Principia Philosophia (Amsterdam: Ludovicus Elzevirius, 1650), Zentralbibliothek Zürich, Alte Drucke und Rara, FF 91, p. 266