Figure 14. — Robert Hare's calorimotor (top) 

 and galvanic deflagrator. From American 

 Journal of Science, 18 19, vol. i, plate opposite 

 p. 413, and 1822, vol. 5, plate opposite p. 95. 



than of physical contact,^^ and Antoine Becquerel had 

 devised another such celF'' in the 1820's as a result of 

 Davy's theories. Daniell set out to test Faraday's 

 electrochemical theories, and he devised his nonpo- 

 larizable "Constant Battery" on the results (figs. 15, 

 16, and 17). In Daniell's cell an amalgamated zinc 

 electrode in a weak solution of sulfuric acid was 

 separated by an ox gullet from a copper electrode in a 

 copper .sulfate solution. John Gassiot made a more 

 durable cell by replacing the gullet by an unglazed 



f;,,j 



SmJ^ O'lliA-V Ir ,1 /ill 



Figure 15. — Daniell's "constant" battery. 

 From Philosophical Transactions of the Royal 

 Society oj London, 1836, vol. 126, p. 117, pi. 9. 



porcelain cylinder. ^^ While the high internal resist- 

 ance of the Daniell cell limited the current consider- 



26 Humphrey Davy, "An Account of Some Galvanic Combi- 

 nations, Formed by the Arrangement of Single Metallic Plates 

 and Fluids, Analogous to the New Galvanic Apparatus of Mr. 

 Volta," Philosophical Transactions, 1801, vol. 91, pp. 397-402. 



2' Antoine Becquerel, "Nouveaux Resultats electro- 

 chimiques," Annates de chimie et de physique, 1823, vol. 23, pp. 

 259-260; "De 1' Etat de I'electricite developpee pendant les 

 actions chimiques, et de la mesure de ces dernieres au moyen 

 des effets 61ectriques qui en resultent," Annates de chimie et de 

 physique, 1823, vol. 24, pp. 192-205; "Memoire sur I'electro- 

 chimie et I'emploi de I'electricite pour operer des combinai- 

 sons," Annates de chimie et de physique, 1829, vol. 41, pp. 5-45. 



28 John P. Gassiot, "Account of Experiments with Volta- 

 meters, Having Electrodes Exposing Different Surfaces," 

 London and Edinburgh Philosophical Magazine and Journal of Science 

 (title varies, hereinafter referred to as Philosophical Magazine), 

 1839, vol. 13, pp. 436-439. 



242 



BULLETIN 228: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY 



