Negligence – Causation. The Privy Council, in dismissing the appellant hospital board's appeal, held that, as a matter of principle, successive events were capable of each making a material contribution to the subsequent outcome. It was not persuaded by the appellant's argument that Bonnington Castings Ltd v Wardlaw ([1956] 1 All ER 615) was distinguishable because, in that case, the inhalation from two sources had been simultaneous, whereas, in the present case, the sepsis attributable to the appellant's negligence had developed after sepsis had already begun to develop.