Among St Amands many treatises was one on the magnet. His pharmacopoeia was the Commentary on the Antedotary of Nicholas'.
Like Roger Bacon (c. 1219–c. 1292)) after him, St Amand wrote on experimental method. The historian of science Lynn Thorndike explains that St Amand "asserts that experimentum alone is timorous and fallacious, but that fortified by reason it gives experimental knowledge." In his view, what St Amand meant was that experimentation had to be methodical, and used alongside theory. On simples used in herbal medicine, St Amand stated specific rules for practical testing: he advised that the specimen had to be pure; that the test should be on a simple disease; that the test be repeated; and that the dose should depend on the patient. Thorndike notes that both St Amand and Albertus Magnus preceded Bacon in their use of the phrase "experimental knowledge".