Louis Vaillant

He was the second son of Léon Louis Vaillant, professor of zoology at the French National Museum of Natural History in Paris.

[3] He upheld a medical thesis at Bordeaux in 1902 on damage to internal organs caused by snake venom.

He was the expedition's doctor and also naturalist,[3] acting on behalf of the Musée National d'Histoire Naturelle; progress was reported in the Bulletin of the museum by his father.

[6] The expedition left St Petersburg on 17 June 1906 and proceeded via Bokhara, Kashgar, Ürümqi and Turfan, before reaching Peking in the summer of 1909.

In March 1908 the expedition visited Dunhuang, where numerous cave manuscripts were purchased and subsequently studied by Pelliot.