Monday 28 December 2020

Dusty Death

. . . and all our yesterdays have lighted fools the way to dusty death. [Macbeth]

A hit, a very palpable hit! [Late Hamlet] I'm a great believer in reading outside my echo-chamber: random books have done me proud in the past. I was scanning the severely limited inventory on Borrowbox to land some audio-book fish for the holidays: nothing nothing nothing nothing nothing . . . Trace by Prof Patricia Wiltshire. My female relatives read a lot of bodice-rippers body-rippers murder mysteries; many of them far too challenging for me. The genre has come a ways since Sherlock Holmes solved the problem by taking a rattling train to Dartmoor and smoking a couple of pipes. Patricia Cornwell, for one example, tends towards grizzly details of bodies in bin-bags . . . the flies, the flies. I started one of her books and could not finish it.

Patricia Wiltshire, contrariwise, is strictly non-fiction; but works in the same arena as a forensic palynologist. Palynology is the study of scattering παλύνω ultimately from dust πάλη [aaarggh not the dreadful Gwyneth Paltrow's shameful concoctions]; and forensic is the application of science to crime. Wiltshire used to be a lot of things including a botanical archaeologist, but her core bailiwick now is collecting and characterising plant pollen and fungal spores from dead bodies, brake-pedals and bin-bags;
 and matching those data to a location. Making that connexion in a way that will convince a jury and outsmart a defense attorney requires an encyclopedic knowledge built up from 40 adult years of staring down a microscope with the fingers of one hand marking several different pages in a weighty Victorian botanical memoir. The internet has a been a boon to her because she can rapidly get a second opinion or pull on a distant colleague's coat for their niche expertise.

She was over 50 years old before [the out-of-box thinking branch of] the police networked themselves up against her by telephone . . . because Kew Botanic Gardens couldn't help them progress their case. She's in her late 70s now, but still in the saddle and widely respected for her dedication and professionalism. She was early on able to suppress her gag reflex by resolutely affirming her belief that dead bodies are no longer people. Although this needed some effort when she was presented with cauliflower cheese in the police canteen after working in the morgue. The smell of sulphur from the brassica and butyric off-milk from the cheese is just what the intestinal flora produce in their post-mortem work.

I know that Trace is a Jo Public version of the forensic process rather than a scientific article, but I'd be more confident of the results if the evidence was treated double-blind. Bias will creep in if the analyst knows whence the sample originates. Nevertheless there are many stories of uncanny precision in describing a locating crime-scenes from the quantitative and qualitative analysis of microscope slides. In one case, Wiltshire is driven out to the site after she has analyzed the pollen profile from the perps' shoe scrapings. She walks along a field-boundary hedge until she stops where a blackthorn and a whitethorn-with-ivy rear up over a little clump of dead-nettle . . . "Here!" she announces [correctly] to the trailing policemen. No other location along the 300m hedge would deliver the unique combination of pollens. For her, "a lawn is a lawn is a lawn" is simply not true: if you get down on your knees and look it is infinitely variable. Although that lawn is very different in its palynological profile to a wooded glade, despite being probably dominated by the same three species of grass.

Verdict: this is a book worth reading as an antidote to Agatha Christie or CSI on the telly. It shows that results that come from hard work are rewarding and useful while results that come quickly might be suspect because superficial. Forensic palynology, and indeed archaeological palynology, requires the mastery of many different disciplines - botany, parasitology, geology and statistics for starters - and weaves many threads of disparate evidence into a coherent tapest[o]ry. Hear it on BBC from the horse's mouth?

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