[1] His father John Mitchell was a member of the Tasmanian House of Assembly.
[3] Mitchell studied for five years as a doctor in Dublin but dropped out to complete civil service work and never took his final examinations.
[4][5] In the early twentieth century he occupied the post of Secretary of the Congested Districts Board for Ireland.
[4] Mitchell aimed to show that most of the ills afflicting mankind are due to poisons manufactured in the body from bad food choices and he provided reasons for believing that much of this arises from gastric indigestion.
[7] Mitchell opposed the use of "salted or preserved foods" and favoured a diet rich in fresh fruit and salads.