That things are changed, and that nothing really perishes, and that the sum of matter remains exactly the same, is sufficiently certain.
'Cogitationes de Natura Rerum' Cogitatio 5 in J. Spedding (ed.) 'The Works of Francis Bacon' vol. 3 (1857) p. 22 (Latin) and vol. 5 (1858) p. 426 (English translation)