Edouard Silas (1827 - 1909) studied with Friedrich Kaklkbrenner, Francois Benoist and Jacques Fromental Halévy. Silas was born in Amsterdam and lived from 1850 in London.
His Fantasie is an interesting piece. St. Ann's hymne tune has the key D major. The soft Introduction handles the first verse of the D-major-tune with an background of musical "waves" in f sharp minor.
By the way: This Introduction is very simular to the Introduction of Félix-Alexandre Guilmmant's Introduction of "Fantaisie sur deux Mélodies Anglaises" Op. 43.
The second verse is a brillant rhapsodic Toccata.
The last verse presents an Apotheosis of the Chorale tune.