Brian Lawsons burial index has John Thomas Cain 36 buried Braddan July 11 1902.

There is also a John William Cain
In 1901 he was a patient in the Braddan Lunatic Asylum:
John William Cain Patient 38 Married formerly sailor b. Lezayre
This would probably be the son of Thomas and Ann Cain, who was christened on May 1 1865.
He was 6 in the 1871 census.
Bruce