I know nothing about Jack Wheatley, but this sad little headstone in a disused cemetery in what was the original Coolootai Station
demonstrates the struggles families faced prior to modern knowledge of first aid, communication and transport.
Nowadays snakes kill on average, less than one person a year in Australia.

And no death adders have been seen in Coolatai for some time.

Addendum: I found this article about the incident:
Friday 18 february 1910 The Inverell Times.
A Child's ill-Fortune.
Last Wednesday the son of Mr.Wheatley, of Coolatai, near Warialda,
aged 5 years, was bitten by a death adder. His mother scarified and
sucked the wound, and applied ligatures. Upon a doctor's arrival the
child was apparently out of danger, but was found to be suffering from
diphtheria, from which be died.