He then went to Antwerp to continue his studies under Mathieu Ignace van Brée, and in the following year exhibited at the Brussels Salon Christ Healing the Blind.
Among his accomplished works may be named The Last Honors paid to Counts Egmont and Horn by the Corporations of the Town of Brussels, now at Tournai; The Death of Egmont, in the Berlin gallery; the Coronation of Baudouin, Emperor of Constantinople, painted for Versailles; The Temptation of St Anthony, in the palace at Brussels; The Siege of Antioch, Art and Liberty, Portrait of M. B. Dumortier and The Plague at Tournay, all in the Brussels gallery.
"M. Gallait has all the gifts that may be acquired by work, taste, judgment and determination," wrote Théophile Gautier.
No doubt, this Walloon artist, following the example of the Flemings of the Renaissance and the treatment of Belgian classical painters and the French Romantic school, sincerely aimed at truth.
As an artist employed by the State, he exercised considerable influence, and for a long time he was the leader of public taste in Brussels.