anode & cathode

Over the next few years, Faraday merged his knowledge of chemistry with the developing field of electricity. Years before, Davy had figured out how to separate metals by passing an electric current through them. Faraday called this process electrolysis, the chemical decomposition of a compound by sending an electric current through it. In 1833, he established two basic laws of electrolysis. The first law stated that the quantity of metal liberated was proportional to the quantity of electricity used. The second law stated that the electricity required to liberate the unit equivalent mass of any element was precisely the same. To describe his research, he had to make up several new words, including anode, cathode, electrode, electrolyte, anion, and cation. These are now an essential part of scientific vocabulary.

Katherine Cullen, Physics : The People behind the Science, Chelsea House, 2006.

【電気】 アノード 《正電荷が流れ出す電極; ⇔ cathode》:
1 (電解槽・電子管の)陽極.
2 (蓄電池などの)陰極.
[ギリシャ語 ‘a way up’ の意][研究社新英和中辞典]

【電気】 カソード 《正電荷が流れ込むほうの電極; ⇔ anode》:
1 (電解槽・電子管の)陰極.
2 (蓄電池などの)陽極.
[ギリシャ語 ‘a way down’ の意][研究社新英和中辞典]


The electrode that undergoes oxidation is called the anode. You can easily remember this if you burn the phrase “an ox” (for anode oxidation) into your memory. The phrase “red cat” is equally useful for remembering what happens at the other electrode, called the cathode, where the reduction reaction occurs.

Peter J. Mikulecky et al., Chemistry Workbook for Dummies, Wiley, 2008.

cathode-ray tube:陰極線管,ブラウン管,CRT.

In the early days of television, when there were only half a dozen channels at most, significant, well-written dramas on a cathode-ray tube could still make us feel like members of an attentive congregation, alone at home as we might be. There was a high probability back then, with so few shows to choose from, that friends and neighbors were watching the same show we were watching, still finding TV a whizbang miracle.

Kurt Vonnegut, Timequake, 1997.

Electrochemical science also owes to Faraday many terms that are now taken for granted, including electrolysis, the process of decomposing a chemical solution by means of electricity; electrolyte, the substance in a solution being decomposed; electrode, the conductor by which the current enters or leaves the solution; cathode, where the current leaves (the negative electrode); anode, where the current enters (the positive electrode); ion, the charged particle in the solution; cation, the ion that is discharged at the cathode; and anion, the ion that is discharged at the anode.

The first two terms were probably invented by a friend of Faraday’s, Dr. Whitlock Nicholl, and the rest were devised by the mathematician William Whewell, Master of Trinity College, Cambridge (who also invented the word “scientist”). But although Faraday did not originate the terms, he popularized them, introducing them in a paper he read in a lecture in early 1834 and published in the Philosophical Transactions shortly afterward.

Colin A. Russell, Michael Faraday : Physics and Faith, Oxford University Press, 2000, p.94.


メールアドレスが公開されることはありません。 * が付いている欄は必須項目です