Relationship between perfumes and colors

Les sens sont des especes d'instruments dont il faut apprendre a se servir (Voltaire—Traite de Metaphysique). When a stimulus is perceived by the perceptive system coupled with another sense, one is in the presence of a case of synesthesis. But pseudocases of synesthesis may exist, where it is only psychologic or affective relations which provoke or facilitate such exchanges. These have been studied by the author according to relations between vision of colors and olfactive or gustative senses.