General

"For the Brigadier from New South Wales Bridges made the experiment of selecting, on an estimate of his character, a very young and comparatively untried officer, a Sydney barrister, H. N. MacLaurin.  MacLaurin was the son of one of the most respected public men in New South Wales, Sir Normand MacLaurin, a Scotsman, once a leading Sydney medical man and for years the Chancellor of the University of Sydney.  Young MacLaurin had been in the militia since his university days, and had recently been promoted to Lieutenant-Colonel commanding the 26th Infantry of the of the citizen forces."

The Official History of Australia in the war of 1914-1918, BEAN, C E W, The Story of Anzac, volume 1, 11th edition, page 50, The "A.I.F" (source 1)

"Irvine was shot at 3 p.m.  Ten minutes later MacLaurin, standing in his shirtsleeves behind the southern shoulder of the ridge which bears his name, was shot from the same point.  He died without knowing of Irvine's death.  The command of the 1st Brigade was given temporarily to Colonel Owen, of the 3rd Battalion, who was at Steele's Post on the same ridge."

The Official History of Australia in the war of 1914-1918, BEAN, C E W, The Story of Anzac, volume 1, 11th edition, page 521, Second Counter-Attack (source 1)