Carl Linnaeus, The Lapland Journey, translated by Peter Graves (Edinburgh: Lockharton Press, 1995), p. 43.

Medelpad, 17/05/1732, ¶141:

From the top we viewed the countryside, the villages with their fields and pastures, the lakes and the sea etc. lying below us. But there was a smoky haze between us and the hill itself, though when we descended we could no longer see it so it must have been the exhalations of the earth.