The letters of Faraday and Schoenbein, 1836-1862 : with notes, comments and references to contemporary letters / edited by Georg W.A. Kahlbaum and Francis V. Darbishire.

Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: The letters of Faraday and Schoenbein, 1836-1862 : with notes, comments and references to contemporary letters / edited by Georg W.A. Kahlbaum and Francis V. Darbishire. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    out of the fluid; another common wire is ])ut into tlie same acid, likewise havinf^ one of its ends rising above the level of the fluid. The jjart immersed of this wire will, of course, be acted upon in a livel}' manner. If the ends of the wires which -are out of the acid be now made to touch one another, the indifferent wire will instantly be turned into an acti\ e one, what- ever may be the lengths of the ])arts of the wires not immersed. (If there is an}' instance of chemical affinit}' being transmitted in the form of a current b}' means of conducting bodies, I think the fact just stated may be considered as such.) It is a matter of course that direct contact between the two wires in cjuestion is not an indispensabl}' necessary condition for communicating chemical activity from the active wire to the passive one; for any metal connecting the two ends of the wires renders the same service. Before passing to another subject, I must mention a fact, Avhich seems to be one of some importance. An iron wire curved into a fork is made to touch at its bend a wire provided with an oxidized end; in this state of contact both are intro- duced into nitric acid of sp. gr. 1.35 and 30, so as first to immerse in the acid the oxidized end; the fork will, of course, not be affected. If now a common iron wire be j)ut into the acid, and one of the ends of the fork touched by it, this end will immediately be acted upon, whilst the other end remains passive; but as soon as the iron wire with the oxidized end is put out of contact with the bend of the fork, its second end is also turned active. If the parts of the fork rising above the level of the acid be touched b}' an iron wire, ])art of which is immersed and active in the acid, no communication of chemi- cal activity- will take place, and both ends of the fork remain passive; but by the removal of the iron wire (with the oxidized end) Irom the bend of the fork this will be thrown into chemical action. As all the phaenomena sjjoken of in the ])receding lines are, no doubt, in some wa}' or other dependent upon a peculiar electrical state of the wires, I was very curious to see in what