Etienne Olivier was a clerk to the lawyer, Antoine Ratier. He was related to Herbert Olivier.
Olivier's employer, Ratier, represented JW in Paris. They were involved in the Eden trial, property leases and a case of counterfeit lithographs, among other things. Olivier's calling card states his address to be 24 rue Vignon.
MacDonald, Margaret F., James McNeill Whistler. Drawings, Pastels and Watercolours. A Catalogue Raisonné, New Haven and London, 1995.