The iconic Skeleton and Roses image used by the Grateful Dead was lifted from which 19th century book?

The skull and roses design was composed by Alton Kelley and Stanley Mouse, who added lettering and color, respectively, to a black and white drawing by Edmund Joseph Sullivan. Sullivan's drawing was an illustration for a 1913 edition of the Rubaiyat of Omar Khayyam. Earlier antecedents include the custom of exhibiting the relic skulls of Christian martyrs decorated with roses on their feast days. The rose is an attribute of Saint Valentine, who according to one legend, was martyred by decapitation. Accordingly, in Rome, at the church dedicated to him, the observance of his feast day included the display of his skull surrounded by roses.[111] This was discontinued in the late 1960s when Valentine was removed from the Roman Catholic canon, along with other legendary saints whose lives and deeds could not be confirmed. Kelley and Mouse's design originally appeared on a poster for the September 16 and 17, 1966 Dead shows at the Avalon Ballroom.[112] Later, it was used as the cover for the album Grateful Dead (1971). The album is sometimes referred to as Skull and Roses