sentences:  It was discovered by Lionel Whitby at the British firm May & Baker Ltd and logged in their Test Book on 2 November, 1937 under Code No M&B 693.During the aftermath to the disastrous convoy SC7, in October 1940, Surgeon-Lieutenant John Robertson, RN, of HMS "Leith", saved the life of Commodore Lachlan MacKinnon, from the torpedoed "Assyrian", who had developed pneumonia, by giving him M&B 693, despite Robertson never having used it before and not knowing the required dosage.M&B 693 was successfully used to treat Winston Churchill's bacterial pneumonia.