Royal Institution (1)

My dear Sir

I do not know that much has been published (anterior to my own papers) respecting the length of time in which a battery can remain in action Some of the French & Italian philosophers by very weak solutions have retained them in force for a long while. (2) Various causes influence the durability of the action but in the first place and before referring the phenomenon to any cause it is essential to observe whether the battery has been open or closed for the whole time. A closed battery or one in which the circuit is complete is soon becomes inactive if opened & left for a time it recovers somewhat but if closed soon falls again. A battery retained open constantly will almost always shew energetic powers for a short time when closed.

You will see in my papers (1000. 1001. 1002. 1120) (3) &c a battery described which if the poles are not retained in communication will be ready for action after any length of time; but your battery is not likely to be of such a nature, it is I suppose an ordinary battery which has been left unclosed, and in order to know its present force you should not merely ascertain that it can decompose water &c but how long it will continue to decompose it & how much water it can decompose.

Ever Dear Sir Most truly yours

M Faraday

 1) Royal Institution, London.

 2) Antoine César Becquerel, “Du Développement de l’électricité par le contact de deux portions d’une métal, dans un état suffisamment inégal de température; des piles voltaïques construites avec des fils d’un meme métal et meme avec un seul fil, et de quelques Effets électriques qui naissent dans les combinaisons chimiques”, Annales de Chimie et de Physique v.23, pp.135–154.

 3) Michael Faraday, “Experimental Researches in Electricity. – Fifth Series. On Electro-chemical Decomposition”, Philosophical Transactions of the Royal Society of London, v.123, pp.23–54.