Described as "a native of Cork" in the first report of his death, the best fit I could find was a Jeremiah Hartnett, whose birth was registered in Killarney, some 40-odd miles northwest of Cork, in 1870. The Cardiff Jeremiah was aged 38 at the date of his death.
WAR HERO'S SUICIDE.
Head Over the Gas Stove.
Alarmed at the non-appearance of a tobacconist named Hartnett, Eldon Road, Cardiff, the neighbours this morning climbed over the garden wall. On looking through the kitchen window they saw Hartnett lying across the table with his head over the gas stove. On entering the kitchen they found Hartnett dead, and the gas turned on. Deceased, a native of Cork, retired from the army three years ago. He served with the Royal Engineers in the Boer War, and was with the Ladysmith relief column.
Dundee Evening Telegraph, Tuesday 3rd November 1908
A CARDIFF SUICIDE
Exhaustive inquiries in Aberdare and Cardiff have failed to find any relative of J. Hartnett, tobacconist, of Eldon-road, Cardiff, who was found asphyxiated in his house on Tuesday evening.
The body has been removed to the mortuary and the police are in possession of the house and shop.
The Evening Express, Thursday 5th November 1908
SUICIDE BY GAS
Mr. Frederick Jones, deputy-coroner, held at an inquest at Cardiff on Friday on the body of Jeremiah Hartnett, of Eldon-road, whose death under singular circumstances has been reported.
Gladys Richards, Chancery-lane, a girl who assisted the deceased in his tobacconist business, gave evidence of identification, stating that when she last saw Hartnett on Sunday he complained of headache. Going to the house on Monday she got no reply. She had never seen deceased peculiar in his manner, nor was she aware that he was in any position of difficulty. He had been indisposed for a week. He never said he had been invalided home from South Africa.
Police-constable John Harvey said that when he burst the back door he found the place full of gas, and in the kitchen he saw deceased lying across the table and gas stove, face downwards. A jet had been turned on, and gas was escaping near his face. Witness had made inquiries, but had failed to discover the man's history. He possessed two medals and seven bars for service in the Royal Engineers.
Dr. M. Pittard (divisional surgeon) attributed death to poisoning by gas.
The War Office has been communicated with, but so far nothing has been ascertained to shed any light on the man's antecedents.
The jury returned a verdict of "Suicide by gas poisoning," and found there was nothing to indicate the state of his mind at the time.