Note 18 — PART I. THE CHANGES UNDERGONE BY ANTIQUITIES IN EARTH AND IN AIR.
George A. (George Augustus) Auden translation
Olshausen often noticed on freshly excavated antiquities of various kinds a peculiar smell of resin or gum, especially after treatment with hydrochloric acid (“Verhandl. d. Berl. anthropol. Ges.,” 1884, p. 520). It may be supposed that this odour is due to the traces of hydrocarbons present.