Frogs’ Legs, Thermoelectricity, and Hans Christian …...H.C.Oersted,1830.[1] There is NO ELECTROLYSIS Occurring Here Thermoelectricity of InhomogeneousMetals Conclusion Keith Walsh

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T2T2T1T1 T2T1

Volta’s Prior Experiments with Frogs’ Legs

Hans Christian Oersted (1777 to 1851)

Professor Anatychuk of the UkraineInstitute of Thermoelectricity hasproposed that Volta should be creditedwith the discovery of thermoelectricityfor this work.[2]

More than 25 years earlier, the Italianscientist Alessandro Volta had describedexperiments in which he had caused afrog’s leg to palpitate by connectingacross it a single metal bar, which hadbeen heated at one end by immersion inhot water.

"It is very remarkable that,notwithstanding all that has beenmentioned, the thermo-electric circuitmakes a prepared frog's leg palpitate.The communication between theextremities of the circuit and the nervesof the frog were made by means ofplatina wire, in order to guard against theinfluence of unequally oxidatedsurfaces.“H. C. Oersted, 1830. [1]

There is NO ELECTROLYSIS

Occurring Here

Thermoelectricity of

Inhomogeneous Metals

Conclusion

Keith Walsh – Independent Researcher

Frogs’ Legs, Thermoelectricity, and Hans Christian Oersted

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The Danish scientist Hans ChristianOersted played a key role in promotingThomas Johann Seebeck’s earlydiscoveries in thermoelectricity:

ΔT ≤100ºC

Hans Christian Oersted

Both Volta and his contemporary LuigiGalvani had also detected palpitations infrogs’ legs using bi-metallic arcs as thecontacts, but had never cited the role oftemperature difference in theseexperiments.

L. I. Anatychuk

However, in 1830 it was reported againthat frog’s legs could be stimulated bythe thermoelectric effect alone.

"Dr. Seebeck has also succeeded inproducing a thermelectric current in asingle metal, but this succeeded onlywith metals that have a quite perceptiblecrystalline texture so that the variousparts of a crystal then seem to play therole of different metals.”H.C. Oersted, 1823.[1]

Seebeck’s work had shown thatthermoelectric effects from dissimilarmetals in contact with each other aregreater than those from single metals.

The microstructure ofa typical dentalamalgam provides agood example of aninhomogeneous mixtureof dissimilar metals.

“Dr. Seebeck has discovered that anelectric circuit can be produced in metalswithout the interposition of any liquid. Itconsists of two arcs of different metals.In order to produce the current, thecircuit is heated at one of the two placeswhere the two metals touch.”H.C. Oersted, 1823.[1]

Seebeck was never able to measure thethermoelectric effect in singlehomogeneous materials, but he diddetect it in material samples which heknew to be inhomogeneous. Once again, itwas Oersted who recognised thesignificance of this discovery:

Thermoelectric eddy in metal inclusions Amalgam fillings in teeth

A requirement exists for experimentalinvestigations to be carried out in orderto determine whether the thermoelectricpotentials generated by metal amalgamdental fillings are able to dissipateelectrical energy through the nerves inpeople’s heads.

“When the author has clearly announcedthe discovery, has derived it from gooddata and conceived its connections withother truths, the merit of theexperimental philosopher is only that ofhaving confirmed it by experiment, whichstill in many cases can be a work of nosmaller claim to glory than the primitiveconception itself.”H.C. Oersted, 1830.[1]

References:

[1] Selected Scientific Works of Hans Christian Oersted, Princeton University Press; Jelved, Jackson & Knudsen

[2] On the Discovery of Thermoelectricity by Volta, Journal of Thermoelectricity No2, 2004; L. I. Anatychuk.

T2 – T1 = ?

Pt Contact

Pt Contact

Frog’s Leg

T2

T1

T1

Cu

Fe

σ denotes thermoelectric coefficient



Nevertheless, a review of the Norwegian experience ofthe phase-out of dental amalgam states the following –“many research gaps existed, which, if addressed,may settle the dental amalgam controversy once and forall.” [4]Thermoelectric Eddy In Dental Amalgams

Amalgam Phased Out In Denmark, Sweden and Norway

Thermoelectric Eddy Current in Bio-Compatible Materials


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However, and in spite of the fact that amalgam fillingsare placed in children’s teeth, it appears thatexperimental procedures to measure the thermoelectricbehaviour of a typical dental amalgam have never beencarried out.

Dental amalgams are in-homogeneous mixtures ofdissimilar metals. Due to themethod by which they areformed, their degree ofmaterial inhomogeneity ismuch greater than that ofany true alloy [3].

Eddy Current In Inhomogeneous Materials

“In the inhomogeneous isotropic medium,thermoelectric force occurs when thecontour is not isothermal.” [1]

L. I. Anatychuk

References:

[1] Physics of Thermoelectricity, L. I. Anatychuk

[2] Thermoelectric Effect with Magnetic Readout, Hinken & Tavrin

[3] The Difference between An Amalgam And An Alloy, K. P. Walsh

[4] Review of Norwegian experiences with the phase-out of dental amalgam use, John M. Skjelvik

The current induced bythe thermal gradientgives rise to anelectromagnetic effectwhich can be detectedat the surface.

This phenomenon is used in thefield of non-destructive testing toreveal the presence of impuritiesin metals. [2]

The materials used inrestorative dentistryare not exempt fromthe laws of nature.

And nor should they beexempt from the levels ofscrutiny normally affordedto materials used in bio-engineering applications.

It has been suggested that thethermoelectric behaviour of metal dentalfillings may be the real cause of manyneurological and so-called “psychiatric”disorders. However, it appears that no-onehas bothered to ask the authorities inthose countries where amalgam has beenphased out if the incidence of suchdisorders has been reduced or not.

Research Gap

There is no scientific evidence to suggest that thethermoelectric potentials generated by amalgam fillingsare not able to dissipate electrical energy through thenerves in people’s heads.

It appears thatthe experimentsrequired to showit have neverbeen carried out.

Therefore at present welack the required evidencefor a valid scientificunderstanding of thisproblem.

We feel that it should be possible to devise anexperiment to measure the size of the thermoelectriceffects produced by metal dental fillings.



Thermoelectric Effect in Metal Dental Restorations


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Consider the following twostatements:

a) There is no scientific evidence tosuggest that the thermoelectricpotentials generated by metalamalgam dental fillings are able todissipate electrical energy throughthe nerves in people’s heads.

b) There is no scientific evidence tosuggest that the thermoelectricpotentials generated by metalamalgam dental fillings are not ableto dissipate electrical energythrough the nerves in people’sheads.

If experimental investigations tomeasure the thermoelectric potentialsgenerated by amalgam fillings havenever been carried out, then each ofthese statements may be accuratelydescribed as all of the following:

1) Perfectly correct.

2) Perfectly consistent with theother.

3) Completely meaningless.

An amalgam is unlike any true alloy.

It has a much more inhomogeneousmicrostructure.

However, and in spite of the factthat amalgam fillings are placed inchildren’s teeth, it appears thatexperimental procedures todetermine the thermoelectricproperties of a typical dentalamalgam have never been carriedout.

Students in dental schools havebeen routinely taught to believethat dissimilar metals in contactwith each other are only able togenerate an electrical potential ifthey are in contact with anelectrolytic fluid and theybecome involved in an electrolyticreaction with it.

As a result, practicing dentistshave been able to justify placing amulti-metal device of the typeshown here (right) in a patient’smouth without knowing anything atall about its thermo-electricbehavior, on the grounds that if itshows no sign of electrochemicalcorrosion then it cannot begenerating any electrical potential.

It is proposed that scientificallyconducted investigations wouldprove this presumption to beincorrect.

Contacting metals in dental restoration.

Close-up of Somatom X-ray, London, 1991.

Dark regions are “unreacted” metal alloy.

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Frogs’ Legs, Thermoelectricity, and Hans Christian …...H.C.Oersted,1830.[1] There is NO ELECTROLYSIS Occurring Here Thermoelectricity of InhomogeneousMetals Conclusion Keith Walsh