If John BRAIN, born about 1782, lived at Cricklade (according to the 1851 census) and not christened in the Cricklade parishes, he was probably christened in a neighboring parish, maybe the childhood home of his father or mother.
John was NOT baptized in the Purton parish. However, it is possible that James BRAIN, baptized 1778 in Purton, is his brother. Purton lies due south of Cricklade.
Requesting a christening lookup in Minety, due east of Cricklade, for the record of John BRAIN, about 1782.
THANK YOU.
Diane