Was this the man who supplied the chemical know-how for faking the Turin Shroud - 13th century Paul of Taranto?

Update 30 June 2015  Looking back through my older postings, I came across this one. Folk may be puzzled by the abrupt switch from sulphuric to nitric acid with no reasons being given. That's because I had been using the Comments facility on a different site to hint at a rapid sea change in thinking.

The caption reads: "Paul of Taranto was a 13th century Franciscan alchemist and author from southern Italy. Perhaps the most recognized of his works is his Theorica et practica, which defends alchemical principles by describing the theoretical and practical reasoning behind it. There is also evidence to suggest, however, that Paul is also the author of the much more widely known alchemical text Summa perfectionis, generally attributed to Geber (aka "Pseudo-Geber")

Here's the first known recipe (in precise detail) for making nitric acid fumes (which might, just might, have been used to produce the Shroud image via its propensity to oxidize and 'nitrate' (verb) organic matter, turning it sepia or yellow-coloured in the process).

"Take a pound of Cyprus vitriol, a pound and a half of Saltpetre, and a quarter of a pound of alum. Submit the whole to distillation, in order to withdraw a liquor which has a high solvent action. The dissolving power of the acid is greatly augmented if it be mixed with some sal ammoniac, for it will then dissolve gold, silver and sulphur"

Cyprus vitriol is copper sulphate, saltpetre is potassium nitrate, and alum is potassium aluminium sulphate. (Sal ammoniac is ammonium chloride, but is not needed to generate nitric acid).

Here's a mechanism that has been proposed for what happens when a simpler binary mixture of copper sulphate(CuSO4) and  potassium nitrate (KNO3) is heated to a high temperature (600 degrees C or higher). The chief end product, nitric acid, is shown in red ( HNO3)

2CuSO4  → 2 CuO + 2SO2 + O 2  

KNO3 + SO2 → KO3SONO

2 KO3SONO → N2O3     + K2SO 4  + SO3

If the cooling is insufficient, N2O3  decomposes spontaneously:

N2O3  →  NO + NO2

or otherwise reacts with water:

 N2O3  + H2O  → 2HNO2

and the subsequent disproportionation of HNO2  produces HNO3 :

3HNO2  →  HNO3  + 2NO + H2 O

 

Oxygen produced in the first reaction oxidizes NO:

2NO + O2  →  2NO2

and the dissolution of the resulting oxide in water yields further nitric acid:

4NO2  + 2H2 O + O2  →  4HNO3

 These days the reaction is accomplished faster and more easily by heating a mixture of potassium nitrate and concentrated sulphuric acid, H2SO4, in a glass retort, or other all-glass apparatus, i.e. no corks, rubber bungs or other organic matter.

The nitric acid collects as a liquid in the cooled receiving flask on the right. It will be yellow or brown due to dissolved nitrogen dioxide (an impurity). There may be other oxides of nitrogen too (thus the references to NOx to avoid being too specific)

So what's this got to do with the Turin Shroud? 

 I propose that the Turin Shroud  image may have been formed by a reaction between nitric acid and/or nitrogen oxides (NOx) acting upon organic matter, notably carbohydrates (oxidation) and even protein (nitration). It may even account for the blood that is "too red".

I provisionally call it the HNO3/NOx fumigation theory.You read it here first, correction - second. I dropped some hints yesterday on shroudstory.com. (See later comments). The key concept is that of fumigation, note, with relatively little liquid water. Details to follow in the next days and weeks (nitric acid  is on order for a new round of acid experimentation, close on the heels on my H2SO4 mini-project - see the posting immediately preceding this one)

Methinks that'll do for now. I'll give details in future postings, and suggest how the hypothesis can account for a considerable number of Shroud characteristics (the latter collectively earning it the description "enigmatic") and potentially be tested, possibly  falsified. Please note: it's just a hypothesis for now: my interest is less to do with debunking the authenticity of the Shroud, and more to do with trashing the absurd notion that the Shroud HAS to be of supernatural origin. See that woeful article in the Independent, December 2011, the one that prompted this blogger/retired biomedical scientist to go 'mixing it' with the purveyors of pseudo-science.

Further reading:

On Pseudo-Geber/Paul of Taranto: preview of  William R.Newman's critique: 

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