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Christoph H. Pfaff and the Controversy Over Voltaic Electricity

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Christoph H. Pfaff and the Controversy Over Voltaic Electricity Bull. Hist. Chem., VOLUME 25, Number 2 (2000 8 CHRISTOPH H. PFAFF AND THE CONTROVERSY OVER VOLTAIC ELECTRICITY l Krh nd Mln M. , Arh Unvrt, nr Introduction r tht r h t h hnr (." h bjt f lt pr Chrtph nrh fff, 28r It h bn 200 r n Alndr lt nvntd ld Grn ht nd pht th h lt hd h f pl, th frt ltr bttr, nd thrb rntl b ntd. fff lrd n n rtd n prtnt trtn tht xprt n lvn pnt nt nl fr th n n, fld f td h f ltrt nd nt ltvtd thrht h ln bt l fr th ltr ltr rr. n ntrb l thnl tht thr tn t nl ltrt nd, hl h trnfrd n prtlr, th ndrtnd t. h ltr n hh n f lt pl d h tll lv n rnbl b fr n Wlhl trd b t lt dv Otld v 86 h r. pl dtl b tr f ltrhtr. A th bjt f ntn rdn t Otld, fff ntf nvttn, "pntn htrn f hh nldd thrtl lvn nd zl d d f th rn f th l fndr f vlt" h "n trl tnn tht d t pl rt prtlrl n r pntnl f nl th prptn f th nl t dffrnt tl r d f lvn phnn brht n ntt. h n Grn (2." In ddtn tn frd prnntl n t h nr r n l th n f th frt hlf f trhtr nd nrn th nntnth ntr, nd t nl, th vrtl fff pd pht nd pblhd n ppr nd ht l. Indd, t tht b n bjt f ph, t th prtn btn Figure 1. Chr. fff ( 82. r C. Shdt dn, trl, ph nd htr hd nt Shönb, 300 Jahre Phy sik and Astronomic an der btn, nd phr. t b nft. Kieler Universität, rl . rt. Kl, 6, 26. t hv nn t ntt n Erp nd r In lttr f Otbr 0, 80 t th th n rpndd r hd prnl rltn th prtnt tt Mrtn vn Mr, lt rfrrd t " hhl ntt nd hlr h Cvr, G, , td Grn ntt, zl ltvtr f ph htnbr, Gln, Ørtd, lt, rthllt, hénrd, , ntrl htr, nd htr, nd th thr f 84 Bull. Hist. Chem., VOLUME 25, Number 2 (2000) r Lagrange, Berzelius, Liebig, Faraday, Mayer, and It won him much praise and caught the attention of Volta, Goethe. among others. After further studies in chemistry, phys- ics and medicine he obtained in 1798 a chair at the Chris- Although he was a central figure in the scientific tian-Albrecht University in Kiel. He spent most of the life of his time, today Pfaff is largely forgotten or rel- year of 180 in Paris, and it was here he met Volta and egated to footnotes in works on the history of science. witnessed the Italian scientist's famous demonstration This is probably because he made no significant dis- of the pile in front of Napoleon and other luminaries. coveries, but rather made an impact as a teacher and Pfaff was fascinated by Volta and his marvelous appa- propagator of science and through his many books, re- ratus and immediately took up his own experiments (7). views, and papers. There is indeed a Pfaff included in In 1802 the ambitious young scientist wrote to van the Dictionary of Scientific Biography, but he is Johann Marum (8): Friedrich Pfaff, a mathematician and Christoph's older brother. Curiously, when Chr. H. Pfaff does turn up in I rn t prnt n plt trt n lvn, n hh I hll bl n tt bibliographies and historical writings, his first name is rdr ll th rll thnt ft, nd n hh I often given as Christian rather than Christoph. For ex- hll rd th t th l f ltrt. ample, this is how he is named in the 1863 edition of Poggendorff's authoritative bio-bibliography, in the lt n about Pfaff's project, of which he approved. British Museum General Catalogue of Printed Books On January 23, 1802, he wrote to Pfaff (: (1963), and also in the classical historical works of I vr h pld th r d f pblhn Edmund Whittaker and James Partington. Yet his first trt hh prnt vrthn tht h tn name was Christoph, such as proved by his autobiogra- pl nrnn lvn, nd t pt th ttr n th lrt lht n n l n d t bttr thn phy (3). h r tht hv dn vrl r , [nd] th rdr nd thd tht vrn th, prv f nd Crr it. Although Pfaff's "complete treatise" never materialized, Born on March 2, 1773 in Stuttgart, young Pfaff en- his work earned him a reputation as one of Europe's tered in 1782 the nearby Karl Academy, named after foremost specialists in electrochemistry and galvanism. Württemberg's Duke Karl Eugen. He soon became fas- Ludwig Gilbert, the German physicist and editor of cinated by the scientific subjects that were taught at the Annalen der Physik, wrote that Pfaff (10): Academy in addition to the classical languages. His early knowledge of chemistry mostly stemmed from Friedrich ...hd rd tll n th n fld f ph [nd] th h xllnt rlt tht lt, h Gren's Systematisches Handbuch der Gesammten h t n r, ntrtd h th dvrtn nd Chemie (1787-1790), which he studied by himself. ltvtn h thr n Grn ... [fff] rtl Among his fellow students was the Frenchman Georges n th tnth vl f Annln dr h (th Cuvier, four years older, who would later become such r 802, pp 2 nd 2 tll bln t th t a famous pioneer of zoology and paleontology. The close ntrtv nt f th thr. and, in the spirit of the time, romantic friendship with From 1801 to the end of his life in 1852, Pfaff investi- Cuvier became a turning point in Pfaff's life and rein- gated the action of the pile, defended Volta's notion of a forced his decision to devote his life to science. Cuvier metallic contact force, and wrote widely about voltaic became not only his friend but also his mentor and phenomena. He was considered an international author- teacher. When Cuvier returned to Paris, he kept Pfaff ity on the subject, which he surveyed in 622 pages for regularly informed of Lavoisier's latest works and the the new edition of Johann Gehler's Physikalisches ongoing revolution in chemistry (4). As a result, Pfaff, Wörterbuch. Ostwald later praised the survey for Pfaff's who had originally accepted the phlogiston theory, con- "commendable care and thought (11)." verted to the antiphlogistic doctrines and became an advocate of the new chemistry and its transfer to Ger- Yet galvanic and voltaic phenomena were only part man soil (5). of what Pfaff was concerned with during his busy sci- entific life. He was greatly interested in electromagne- Pfaff completed his medical studies at the Karl tism on which topic he wrote an early "history (12)," Academy with a Latin dissertation on animal electricity and in 1829 he learned from Faraday himself about the (De Electricitate Sic Dicta Animali) which in 1795 ap- new way to produce electricity by means of induction. peared in an extended and revised German edition (6). Bull. Hist. Chem., VOLUME 25, Number 2 (2000) 85 Methodologically, Pfaff favored a positivistic view of chemists and pharmacists. In 1843, on the occassion of science and never tired of emphasizing that chemistry his 50-year's doctoral jubilee, the Danish king conferred and physics were solidly founded on experimentally upon him the title of konferensraad (Conference Coun- established facts. He had no patience for the German cillor), a great honor and a recognition of his services to Naturphilosophie and neither did he like Goethe's re- Danish science and culture. During the last years of his volt against Newtonian science. Having read Goethe's life, Pfaff lost his eyesight and was unable to work in Farbenlehre, he quickly responded with an anti-Goethe his laboratory. He died on April 23, 1852 in his beloved tract repudiating the views of the famous poet and het- Kiel, where he is buried. erodox amateur scientist (13). Much of Pfaff's time was occupied with medicine and pharmacy, and he also con- Polemics I: Pfaff versus De la Rive tributed significantly to analytical chemistry. He devel- oped analytical techniques and wrote in the early 1820s According to Volta, the action of the pile was due solely a practically oriented handbook of analytical chemistry to a contact force (a forze motrice, or electromotive (14), according to William Brock the "first major ana- force) arising between two different metals, and not to Table I. Chronology of Chr. H. Pfaff rn n Stttrt, Grn. 82 Entr Krl Ad. trl drttn (M.. n nl ltrt. 8 rfr (xtrrdnr t Kl Unvrt, Mdl lt. 80 Std n r. Mt lt. 802 ll rfr n htr nd ph. 804 Mbr f th l nh Ad f Sn. 82 Crrpndn br f th rln Ad f Sn. 828 rtr f th Shlltn Snttn rd. 82 t n r U. G . nd ndn (W. rt M.rd. 80 rdnt f th phhtr tn f th (Grn St f hn nd trl Sntt. 8 Chf dtr f th Shlltn phrp. 8 Allt rjtn f hl thr (vn. 88 Grnd Erpn tr. 84 t jr r (rlll. n fr Chr. 82 th. 8 bltn f h tbrph (bnrtrnn. lytical textbook (15)." Among his few contributions to chemical processes of any sort. This view was reflected organic chemistry was an investigation, together with in the title of Volta's famous letter to Joseph Banks of Liebig, of the chemical composition of caffeine (16).
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