Fig. 1
From: Barium, zinc and strontium yellows in late 19th–early 20th century oil paintings
Top: À espera dos barcos (estudo) [‘Waiting for the boats (study)’] (1891, 25.5 × 37.5 cm) by Marques de Oliveira, National Museum of Contemporary Art—Museu do Chiado (Museu Nacional de Arte Contemporânea do Chiado), Lisbon. Bottom: Paisagem (Torres Vedras) [‘Landscape (Torres Vedras)’] (1881–89, 25.8 × 48.8 cm) by Silva Porto, House-Museum Dr. Anastácio Gonçalves (Casa-Museu Dr. Anastácio Gonçalves), Lisbon