eferring to the "condenser [_Kondensator_]
just brought to my attention by Herr Poggendorf" and explains that he
cannot release his treatise "without preliminary announcement of this
subject of the highest importance." (It can be inferred from the text
that the name "condenser" was chosen because of the device's enhancing
of magnetic measurements analogously to the enhancing of electric
measurements by Volta's electrostatic "condenser.")

Immediately on reading the book, Schweigger published extracts, mainly
of the postscript, with indignant comments on Erman's remissness (or
worse) in having failed to mention Schweigger's prior work.[18]

However, Erman was not alone in his unawareness, if it was that, of
Schweigger's discovery.

Rival editor Gilbert of the _Annalen der Physik_ reviewed Erman at much
greater length than Schweigger, reprinting most of the postscript with
evident enthusiasm, and stating in his preamble that the invention is
attributed to "a young physicist studying here in Berlin, Herr
Poggendorf."[19] Only in a footnote is the reader directed to another
footnote in the next article in the volume, where Gilbert finally states
that he "cannot leave unmentioned the fact that this amplifying
apparatus seems to be due to Herr Professor Schweigger." He then quotes
rather fully from Schweigger's first two papers.[16] Oersted in 1823
explained the situation thus: "The work of M. Poggendorf, having been
mentioned in a book on electromagnetism by the celebrated M. Erman
published very shortly after its discovery, became known to many
scientists before that of M. Schweigger. This is the reason for the same
apparatus carrying different names."[20]

The same confusion is well illustrated by the paper to which Gilbert
attached his confessional footnote mentioned above. Written by Professor
Raschig of Dresden, on April 3, 1821, the paper is entitled "Experiments
with the Electro-magnetic Multiplier," but the device, throughout the
paper, is repeatedly referred to in the phrase "Poggendorf's condenser,
or rather multiplier," an awkward combination that suggests editorial
intervention.[21]

The work of James Cumming at Cambridge is described in two papers which
he read to the Cambridge Philosophical Society in 1821, which were then
duly published in the _Transactions_ of that Society. The first, "On the
Connexion of Galvanism and Magnetism," was read April 2, 1821,[22] and
the second, "On the Application of Magneti