February 19. Thursday. 1778. Arose at four O Clock. The Wind and Weather still fair. The Ship rolled less than the day before, and I neither felt nor heard any thing of Sea Sickness last night nor this morning. Monsieur Parison, one of General Du Coudrai’s Captains of Artillery, dined with Us Yesterday, and behaved like [a] civil and sensible Man. We learned from him, that the roads from Nantes to Paris are very good; no mountains, no rocks, no Hills, all as smooth as the Ships deck, and a very fine Country: But that the roads from Bourdeaux to Paris are bad and mountainous.
The Mal de mer, seems to be the Effect of Agitation. The vapours and exhalations from the Sea; the Smoke of Seacoal, the Smell of stagnant, putrid Water, the Odour of the Ship where the Sailors sleep, or any other offensive Odour will increase the Qualminess, but of themselves, without the violent Agitation they will not produce it.