In 1947, the South African Council for Scientific and Industrial Research awarded him a travelling fellowship, enabling him to study in London at the Hammersmith Hospital's Royal Postgraduate Medical School, where he graduated MD in 1947 with thesis Postural Proteinuria.
Shortly after the end of WWII, Willem Johan Kolff, the famous pioneer of hemodialysis, donated artificial kidney machines to institutions in Poland, as well as Amsterdam and London.
In simple terms this involved measuring and replacing fluid and electrolytes lost by the patients to keep them in balance until natural recovery could take place.
He directed the establishment of record linking systems among hospitals and general practitioners and also supported Belfast's flying ambulance service for heart attack victims.
Bull achieved these 3 objectives by feeding the patient a carefully measured, synthetic 'diet' consisting of glucose, peanut oil, and water.
An individual calculation is made for each patient to allow for variation in body build, pyrexia, and extra-renal losses, but the average permissible intake during complete anuria is 500 ml.