[1] He was the son of R. Whyte Mackay of Anderson & Thomson, who ran warehousing at 23/25 Broad Street.
[3] In 1910 he is listed as an advocate living at 26 India Street in Edinburgh's Second New Town.
[4] In March 1926 he stood unsuccessfully as the Unionist candidate in the 1926 by-election for Bothwell.
[5] In May 1928 he took his seat as a Senator of the College of Justice, replacing John Wilson, Lord Ashmore.
In 1931 he sat on the Royal Commission on Licensing, looking at alcohol and public house reforms.