Ganin notes that Mary offers him a piece of a “Blighen and Robinson’s chocolate” bar in their final moments in St. Petersburg together. I’ve not been able to track down this brand reference, but, like the other product placements of perfumes and candies that seem to exist at several points in the novel, this indicates the odd and ironic form that historical specificity takes in Ganin’s memory, whether it be the casual mention of major historical events taking place under his nose, or the cultural products that seem to mark and frame the historical progress of his relationship with Mary.
False Azure: A reading blog of Nabokov's novels
"I was the shadow of the waxwing slain / By the false azure of the window pane"