Induction apparatus Reiniger, Gebbert & Schall around 1892 If you immerse two electrodes with different potential differences U1 and U2 in an electrolyte, a voltage difference arises. If you arrange the metals according to voltage differences ΔU, you get the galvanic voltage series:
Na -2.71 / Zn -0.76, Fe -0.44 / Pb -0.126 // C u + 0.35 / Au +1.5
An element made of Cu and Zn provides a voltage of 1.1 volts: (in a CuSO4 solution) Carbon-zinc element; Electrolyte NH4Cl in a glass vessel. In 1812 Giuseppe Zamboni (1776 - 1846) developed a high-voltage battery made up of up to 4,000 galvanic cells based on the element silver / salt solution / magnesium oxide / silver.
The English chemist John Frederic Daniell (1790 - 1845) followed in 1836 with an element made of Zn / ZnSO4 / CuSO4 / Cu, which was considered to be the first reliable power source and was mainly installed in British and American telegraph systems as it was the only available battery with a lower battery Was self-discharge.
In 1839 or 1840 Sir William Robert Grove (1811 - 1896) developed the Zn / H2SO4 / HNO3 / Pt element. In addition to the Daniell element (copper / zinc), z. For example, a galvanic element can also be produced from copper and silver electrodes: the copper electrode is immersed in a copper sulfate solution, the silver electrode in silver nitrate solution, and these are connected by a wire (electron conductor) with a voltmeter and an ion conductor.
Both the copper atoms of the copper electrode and the silver atoms of the silver electrode “strive” to dissolve in the surrounding liquid and thus to become (positively charged) ions. This formation of ions creates a negative charge on the electrode (because the atoms that go into solution give up their electrons). This would mean that the atoms of the electrode would not be able to dissolve further, as the negative voltage prevents further electrons from accumulating. However, if both electrodes are connected to one another via an electrical conductor, the different dissolution tension of the electrodes ensures that the reaction can continue. Since the redox potential of copper (reducing agent) is lower than that of silver (oxidizing agent), the negative charge in the copper electrode is higher than that in the silver electrode, so there is a voltage at which the electrons are "pushed" towards the silver electrode. This leads to the fact that the solution of the silver atoms is stopped, instead the excess electrons react with the Ag + ions of the silver nitrate solution and ensure that these stick to the silver electrode as normal silver atoms.
The apparatus presented was manufactured by the company Reinige, Gebbert & Schall / Erlangen. Berlin - Munich - Vienna. The University of Paris is exhibiting a similar box (https://www.bium.univ-paris5.fr/aspad/img/gd/electro30.jpg): "COFFRET AVEC APPAREIL ELECTRO-MAGNETIQUE de SPAMER. Pour faradisation. Allemagne approx. 1890. Coffret en acajou avec tiroir de rangement d'accessoires très complet. Régulateur d'intensité de la bobine gradué. Interrupteur de la bobine par double bobine électromagnétique. Pile au bisulfite de mercure en cristal avec dépose de l'électrode en lectrode transport. Coffret remarquablement fini et conçu. Ce coffret figure dans le catalog dentaire 1892 de la maison Geo Poulson de Hamburg ".
American dentists began using direct current for local anesthesia in the mid-19th century. In 1858 the dentist J.B. FRANCIS from Philadelphia / USA even patented electro anesthesia (US patent 20390 from May 25, 1858) ...
Time period
Turn of 19/20th century
Country
Germany
Material
Metal
Size
13x13x13 cm
Item location
68A Krasta str., Riga, Latvia
Article
53_A51317
Price
€ 70
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