This was the case in a trial that took place in 1836, at the Norwich Assizes, when two farm labourers were charged with having attempted to poison a fellow farm servant, by putting “a deadly poison,” blue vitriol (copper sulphate), into a glass of milk. The man noticed that the milk had a metallic taste and only drank a portion of it; but this was sufficient to make him ill for a short time. On the milk being examined it was found to contain copper sulphate, and suspicion pointed to its having been doctored by the prisoners.
The counsel for the defence raised the objection that the accused were indicted for having administered a “deadly” poison, and that medical opinion did not hold that blue vitriol was a deadly poison.
A medical witness called on behalf of the prosecution stated that he considered that copper sulphate was a deadly poison, but at the same time admitted that he had no experience of any case of poisoning in which that salt had been taken.
On the other hand, another doctor asserted that in his opinion the substance was not poisonous, and pointed out that it was not sold as a poison.
The judge, taking into account this conflict of opinion, decided that the matter was doubtful and the prisoners were acquitted.
In the Offences Against the Person Act of 1861 it is provided that any attempt to administer any poison or other destructive thing to any person whether bodily injury be effected or not is guilty of a felony.
As copper sulphate, when taken in quantity, will certainly cause bodily injury, the case tried in 1836 at Norwich, would now probably be decided differently, even though no bodily harm had actually been caused.
This is borne out by the trial of Cluderay, on the charge of attempted poisoning by administering pods of coculus indicus.
No harm had resulted to the intended victim owing to the fact that although the berries themselves are poisonous, the pod in which they are contained is insoluble when swallowed, and this prevents the berries from producing their toxic effects upon the system.
It was decided by the judge, however, that the giving of the entire pod was an administration of poison within the meaning of the Act.