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a physics textbook error, a late reaction



I believe this matter has been solved already, however the following
historical context may be of interest.
Ritter was the first to establish experimentally around 1800 that different
metals show different "conductivity". As "detector" of galvanic current he
used frog legs, as usual at that time. Around 1825 Ohm used a Voltaic pile
and a primitive galvanometer to establish the conductivity of wires made out
of different metal. He found the following conductivity "scale" copper, gold,
silver, zinc, brass, iron, platinum, tin, lead, copper being ten times
"better" than lead at conducting electricity. His scale was flawed, among
other things because of a large impurity content in the silver wires.
Nevertheless this was the very first recorded measurement of conductivity,
published in 1825 (Vorlaufige Anzeige des Gesetzes nach welchem Metalle die
Contactelektricitaet leiten, poggendorf Annalen IV,79,1825 - The preliminary
indications for the law according to which metals are conducting
contact-electricity).In the title of this paper Ohm already establishes the
word "law" for his findings. In later experiments Ohm used a bismuth-copper
thermocouple at a temperature difference of 100° C as a current source, a
suggestion made by Poggendorf. He conducted an extensive series of
measurements, and his conclusions were published in 1827 in his book "Die
galvanische Kette" (The galvanic circuit). In this book the notion of
"potential drop" is first introduced and what we now know as "Ohm's law" is
for the first time enunciated in a more or less recognizable form. A series of
publications by different authors followed soon. Fechner improved on the
accuracy in his work "Maassbestimmungen ueber die galvanische Kette" (1831).
Pouillet confirmed Ohm's law in 1837 and introduced the concept in France and
England. French and English literature of that period often wrongly cites
Pouillet as the inventor of "Ohm's law". Even as late as the 1914 some French
textbooks proclaim "Omh's law was found by Pouillet" e.g. Branly:, Traite
elementaire de de Physique, Paris 1914). Kolrausch once again improved
substantially on the accuracy in 1848. Ohm also investigated fluids,
confirming the applicability of Ohm's law, provided polarizability is taken
into account. Finally Hoppe confirmed the law for flames ("gases"), if both
polarizability and thermal currents are taken into account (1877). Important
work on the subject of conductivity was done among othres by Wheatstone (1855)
and by Kirchhoff (1877). Thus the work of Kirchhoff was performed 23 years
after Ohm's death in 1854. Perhaps also of interest: Ohm was only appointed
full professor at the University of Munich in 1852, at the age of 68.
Incidentally, the oldest references that I could find to "Ohm's law" as such
are: G. Wiedemann's "Die Lehre von der Elektricitaet", published in 1882 and
Jamin and Bouty, Cours de Physique, published in 1883. From both texts it
seems that at that time the phrase "Ohm's law" was already well established in
textbooks.


--
Prof. dr. W. Wieme
Department of Applied Physics
University of Gent
Rozier 44, B-9000 GENT, Belgium
Tel. : +32 - (0)9 - 2643823 Fax : +32 - (0)9 - 2644198