Thursday, December 8, 2016

The Tale of a Nail

Just as those of us obsessed with Franklin's lost expedition were settling in for our nice winter naps, with visions of next year's dives on "Erebus" and "Terror" dancing in our heads, we've been rudely awakened by a fresh scientific study that's making the rounds. Its subject, in fact, is both old and new -- John Hartnell, exhumed from his grave at Beechey Island in 1986, and two samples collected and stored, but not studied until now: one thumbnail and one large toenail. The press stories have tended to vary between thumb and toe in their accounts, but in fact it was both -- and no "clipping" either -- that a team of Canadian scientists used to trace, over a longer period of time than had been possible before, young Hartnell's intake of various chemical elements.

In preparing a voodoo spell, a person's fingernails and toenails are thought to be powerfully efficacious; just so here, science has constructed what the team has dubbed "Hartnell's Time Machine." For, while the visible part of the nail is only of relatively recent growth, the full nail -- from root to tip -- has a longer story to reveal: 19.5 mm in the case of the thumb, 22.5 in that of the toe. Combined, the nails have been used to trace Hartnell's food intake all the way back to June of 1845, just after the ships sailed, through to his death on 6 January 1846 -- nearly seven months. In particular, the team looked at lead, zinc, and copper exposure, as well as at nitrogen stable isotopes. The findings were then compared to a "reference toenail," one associated with a modern individual whose diet included red meat.

The conclusions of the study are fascinating: from the isotopic nitrogen analysis, it was possible to show that, throughout the period, Hartnell consumed no seafood (it's too bad that someone with a knowledge of sailors' eating habits wasn't consulted -- "there needs no ghost come from the grave to tell us this"). As to lead, the results, consistent with other more recent studies, suggest that Hartnell's exposure continued, but didn't increase significantly, during the expedition, though it did rise in the last few weeks of his life, possibly due to his having been given extra rations of tinned food, or some of the "wine for the sick" on board (wine was known for lead contamination at this time). It's also possible that weight loss and illness accounted for the higher relative concentrations. Copper was more of a constant, as was zinc -- though in the latter case, it seems that Hartnell began the expedition and finished it with a severe zinc deficiency. This condition would have increased his susceptibility to illnesses, including TB, and thus could have been a factor in his death. Unfortunately, nails from Hartnell's two grave-mates at Beechey were not available for comparison.

A zinc deficiency could also cause other symptoms -- "depression, anxiety, lethargy, impulsivity and irritability," according to the study. The only remedy would have been fresh meat, which we already know was very scarce indeed; the last time any of the crew would have enjoyed any would have been shortly after arrival in Greenland, when oxen brought on the transports were slaughtered. At the same time, it would be too bad if a zinc deficiency were to be taken -- as, unfortunately, it seems to have been in some press accounts -- as the new "single-explanation" theory. The lack of fresh meat, and conditions of the sailors, on board Franklin's ships would have been very similar to other British naval expeditions of the day, none of which suffered the catastrophic losses of Franklin's, and indeed a recent study (one of whose authors was the late William Battersby) suggests that other causes -- accidents, exposure, scurvy, tuberculosis, and other respiratory conditions -- played a far more prominent role, on the whole, in Arctic expeditions of the period generally. So this new study, while certainly welcome, doesn't necessarily change our prevailing understandings.

The curious can consult the full study here -- it's available for purchase, or can be had via the libraries of subscribing research institutions.

4 comments:

  1. Was it could not or was it would not eat fish? would not if any salted fish was tainted. Could not if the crew did not bring along nets.

    John Ross, in his 1829-1833 voyage , owed his survival to the catching of fish by nets, which in turn allowed the crew to avoid scurvy.

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  2. When reading that I wondered if it was a case of there was no fish to consume or whether he made a conscious choice not to. Maybe he just didn't like it.
    While the loses of the expedition as noted in the Victory Point note were extensive, the fact that no cause was attributed to them makes me think there was no single catastrophic cause.....probably a few from respiratory, a few from accidents etc. I would just think if there was a clear "killer" disease, the single explanation would have warranted mention.

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  3. Despite their association with the sea, fish in the diet of Royal Navy sailors was a rarity on long voyages -- not just Franklin's. The sailors' standard, and preferred, fare was salt pork, bread, and the ration of grog.

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  4. Reading the Study and among others an article in 'Nature' (http://www.nature.com/news/fingernail-absolves-lead-poisoning-in-death-of-arctic-explorer-1.21128)I was not surprised to find Keith Millar, Professor of Medicine at Glasfow Univ., on of William Battersby's co-authers in the study you mentioned, quoted. What surprised me was the oversimplfying nature of his coments. That didn't like him at all, so much so, that I dicided to ask him about the article and know now, that he "was rather disappointed by the so-called "quotations" from my discussion with the Nature journalist - it's not quite what I said to her. [...] The paper is interesting but is based on a sample size of one. The results concerning lead do create difficulties for the lead poisoning hypothesis but I hope that the authors do not now attempt to explain the loss of the whole expedition as caused by zinc deficiency!"
    I'm afraid, that is what will happen, or is henpening already.

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