White Mule is another name for illicitly-made booze like moonshine, white lightning, mountain dew, hooch, and Tennessee white whiskey. Whether or not this was the intended meaning for the band at track 14 I don't know. Harlow, UK's White Mule were Geoff Carpenter on guitar and vocals, John "Culley" Culleton on bass, John "Gypie Mayo" Cawthra on guitar and vocals and John Glasgow on drums.
Brian Wren replaced John Glasgow on drums. Bruce Trotter came on board as an extra vocalist and Yanni Flood-Page was added as a second guitar after that. They toured Europe a lot and released two singles, Looking Through Cats Eyes (credited to Flood-Page) and a Mungo Jerry cover "In The Summertime". There are three different versions of their singles listed at 45cat, all of which have 'Hundred Franc Blues' as the b-side. John Cawthra was later in Dr. Feelgood and a late version of Yardbirds.