Faraday to John Barrow   26 June 1837

Royal Institution | 26 June 1837

Sir

As the trials with copper, tinned iron, and zinced iron, immersed in salt water have now been on for nine weeks¹ I have thought that you might like to know of the result. The copper continues to be corroded over the whole of the surface and is more affected generally than either of the others. The tinned iron plate has continued to shew increasing action, principally at the edges where the iron is to a certain degree exposed, and also at the other parts. The prepared zinced plate has now also given way at the edges and much corrosion has taken place there; the whole surface has also been acted upon. It is as yet the best of the three; but it must be understood that the action on it at the edges (where the iron is partly exposed) and probably therefore at nail holes is greater than upon the edges of the copper[.]

I have the honor to be | Sir | Your Very Obedient Servant | M. Faraday

Sir John Barrow | &c &c &c

Endorsement: 27 June Ack rect and return their Lordship's thanks for the trouble he has been good enough to take on the occasion | JB