Pontifications on Poison
Being some ramblings on events associated with poisonous plants.
Tuesday 15th November 2011
Sometimes I can find that I am very far behind some aspect of popular culture. It’s just happened to me with Tim Minchin, an Australian comedian and accomplished musician and songwriter. I’d heard of him but it’s only recently that I took a wander through the leafy glades of YouTube and saw a number of his performances.
The one that struck me most was what he describes as a nine minute beat poem called ‘Storm’. Storm is a hippyish young woman who espouses all sorts of alternative lifestyles including using alternative, natural remedies. Minchin gives himself the wonderful line ‘Do you know what they call alternative medicine that has been proved to work? – Medicine’ and then goes on to point out that aspirin fits into that category.
By coincidence, I heard that on the same day that I reread the Rev. Edmund Stone’s 1763 letter to the President of the Royal Society giving an account of the successes he had had using the bark of Salix alba, white willow, in ‘the cure of agues’.
Stone’s investigation of the willow bark gives a good clue to the way many remedies were discovered in the past. He states that, in about 1757, he happened to taste a piece of the bark and was struck by its bitterness. This reminded him of the ‘Peruvian bark’, the name given to the bark of trees in the Cinchona genus that contain quinine, and made him wonder if there would be medicinal properties in the willow.
Stone’s letter contains a fair amount of superstitious belief because he says that willow grows in areas of damp and that would suggest that it should be useful in treating diseases associated with the damp. But he notes that, this simple association between place and condition is so well-known and willow is so abundant that he doesn’t understand why no-one seems to used it before.
He says he has looked at ‘dispensatories and books of botany’ but found no reference to its medicinal use. At first sight, this seems strange because it is usually said that Hippocrates wrote of using willow to treat pain around the 5th century BC but that, it seems, was the leaves rather than the bark and it may be that the information about it became lost for some time.
It is certainly true that Pliny mentions it for treating bleeding, gout, corns and other conditions but makes no mention of it as a pain-killer or for reducing fever and the later herbalists, Gerard, Culpepper and Turner, follow this line. But willow is not mentioned at all in the 1712 translation of Pomet’s ‘A Compleat History of Druggs’. Pomet was chief druggist to the French king and his book is, essentially, a catalogue of all the substances available to a pharmacist in the early years of the 18th century.
Stone details experiments using a variety of doses and, sometimes, mixed with the Peruvian bark and takes the trouble to explain the measures he took to ensure that the effects he observed were the result of the willow bark and not something else. I’m not sure how successful he was in eliminating other effects because, in saying that it is efficacious in treating ‘intermitting disorders’ he doesn’t seem to have allowed for the fact that an intermittent condition will have periods of remission.
Stone finishes his letter by saying that his motivation for writing was to give others sufficient information to enable them to conduct their own trials to see if they can replicate his results. It is not possible to say if his suggestion was taken up by others but the absence of any further references to willow bark in the Philosophical Transactions suggests it may not have been.
Certainly, it was at least sixty years later that salicin was isolated from willow and it was not until 1899 that the Bayer company began to market its trademarked product ‘Aspirin’ which is acetylsalicylic acid.