Pontifications on Poison
Being some ramblings on events associated with poisonous plants.
Sunday 30th October 2011
I mentioned 27th October that the Royal Society had made its older Philosophical Transactions available free online. And I said then that I would work my way through any documents concerning poisonous plants.
Since it was Oenanthe crocata, hemlock water dropwort, that first led me to the Philosophical Transactions, back when it cost £27 a time to get access to a single article, I thought I’d start there but I want to do more than just précis cases reported hundreds of years ago.
The earliest specific reference to Oenanthe crocata comes from 1698. It is in the form of part of a letter sent by a Mr Ray F.R.S. to Dr. Sloane. It was Dr Hans Sloane who purchased most of Chelsea and then leased an area including the Chelsea Physic Garden to the Society of Apothecaries for a rent of £5 per annum in perpetuity.
Mr Ray gives details of the poisoning of a group of young lads in Clonmel, Ireland. I was aware of this case because it is mentioned by Mr William Watson FRS in his 1744 letter describing a case involving two Dutch soldiers but had not seen the full details.
There is quite a bit of potential for the story to become distorted because Mr Ray is reporting what was told to him by a Dr. Francis Vaughn who, in turn, was told about it by his brother-in-law, a survivor of the incident, some thirty years after the actual poisoning.
We don’t know if that potential for distortion produced distortion and have to take the story as told. Eight young men went fishing in a nearby brook and found copious amounts of what they took to be Sium aquaticum, water parsnip, but was, in fact, Oenanthe crocata. They ate the roots, raw, in quite large quantities. Soon after, seven of the eight fell ill.
Five suffered convulsions and collapse together with an inability to open their mouths to speak and were dead by the next morning. One seemed to have gone insane but recovered by the morning. The seventh had no serious symptoms at the time but then lost his hair and nails. Only Dr Vaughn’s brother-in-law suffered no symptoms of poisoning and Dr. Vaughn says he doesn’t know whether this was because he ate less than the others or whether his athletic build protected him from the poison.
As soon as the first boy fell down, the brother-in-law set off to run two miles home to get assistance stopping only to take a large drink of milk, direct from the cow, on the way. Dr. Vaughn speculates that the exercise may have sweated out the poison or the milk may have neutralised the poison in his stomach before it could be absorbed.
Mr Ray concludes his letter by mentioning a number of other reported incidents of hemlock water dropwort poisoning before suggesting that people should be warned against eating any unknown herb or root.
There’s a number of interesting points in this account. First, there is no mention of the vomiting and dry retching experienced by ‘Will’ in the incident I blogged about earlier this month (14th Oct) but, clearly, the victims suffered much more severe trismus, an inability to open the mouth, than on that occasion. The convulsions, collapse and mental disorientation do feature in both accounts.
But the other interesting point, for me, is the comparison with an incident dealt with on the Digitalis spp., foxglove, page of this site concerning a young man who made a vegetable quiche using foxglove leaves and was admitted to hospital suffering severe bradycardia. Anything under 50 beats per minutes is considered to be bradycardia but this young man’s heart rate went as low as 28 bpm before recovering. The former nurse who told me the story said it was thought that the victim’s high level of fitness was what made him able to survive.
I’m not sure that anyone has ever systematically examined the general fitness of poisoning victims and, in any event, I’m not sure suggesting that being fit enables to you to withstand poison better would help much to counter the modern problems with obesity in children and young people.