When Captain William Andrew Jarvey, master of a small vessel trading between New Zealand and Australia, murdered his wife in Dunedin by poisoning in 1864, he did so almost in the presence of his 15-year-old daughter, Elizabeth. He was found guilty after a second trial and was hanged in Dunedin Gaol in October 1865. Unfortunately his crime and trial were also responsible for the death of an expert witness who had been brought from Melbourne to testify to the presence of strychnine in the exhumed body of the victim.

Elizabeth Jarvey was putting one of the younger children to bed in the house at Caversham, Dunedin, when she heard loud cries from her mother in the next room, where her father was administering “medicine” to the sick woman. She went to see what she could do, and arrived in time to be told by her mother: “Your father has poisoned me for the woman in the big hat and cloak”. The unfortunate woman then died. A Dr Hardy gave a certificate to the effect that the cause of death was “fits”, but the young girl knew only too well what had happened. Obsessed with the idea of what would happen to the motherless family of five if she disclosed the ugly circumstances, the daughter held her peace for three months, until her father's treatment of her, and the arrival in the house of “the woman with the big hat and cloak”, caused her to change her mind. Jarvey was at once arrested and his wife's body was exhumed in the Southern Cemetery. Stomach samples were taken, but because at that time there was no Government analyst in New Zealand, they had to be sent to Melbourne for examination. Dr Macadam, the Victorian analyst, reported the presence of strychnine in lethal quantities, and Jarvey was put on trial.

According to Dr Hocken, in the Report of Jarvey's Trial, Jarvey was an unsavoury character, being suspected of the murder in Tasmania of several of his illegitimate children. Actually, this damaging fact was injudiciously mentioned by his counsel at his trial. Mr Justice H. S. Chapman presided at the first trial in March 1865, and the strongest possible case was made out against the prisoner. Jarvey's daughter was unshaken both in evidence and in cross-examination, and the defence could make little impression either on the chemist who sold Jarvey strychnine, ostensibly for killing rats on his ship, or on the doctors who also gave evidence. Dr Macadam, however, was anything but at home in the witness box, and quickly fell a victim to astute cross-examination. In addition, he was severely reprimanded from the Bench because of his failure to bring the assistant, who helped in his investigations, into Court, and also on account of some out-of-Court observations he had made to local doctors. His evidence of the existence of strychnine in the body was never broken down, but the attitude of the Court towards him had some effect on the jury. After a retirement lasting from 6.30 p.m. on the Wednesday till 10 a.m. on the Friday, during which time the jurors were kept without food, drink, or fire, they failed to agree and Jarvey was remanded for a new trial.

Dr Macadam returned to Melbourne a very worried man. He had an accident on board ship on his way home, and after his arrival flung himself feverishly into the task of preparing the case for the second trial. But his treatment in Court had become an obsession, and when he left Australia for the new hearing in September, this time with his assistant, James D. Kirkland, he was a very sick man. He died at sea, one day out from Port Chalmers. The verdict at his inquest was “excessive debility and general exhaustion”. He was only 38.

When Jarvey again appeared in the dock, it was before Mr Justice C. W. Richmond, and the prosecutor was C. J. Prendergast, later to be Chief Justice of New Zealand. Kirkland presented both his own testimony and that of Dr Macadam, and it took the jury only four hours to find Jarvey guilty.