W. Saffern¹ to Faraday   19 December 1836

December 19th | 36

Sir

I know it has been a desideratum to discover some substance so far capable of resisting the action of acids as to admit of its being employed in forming galvanic troughs. It occurred to me short time since that sheet caoutchouc might answer the purpose and after trying various experiments for the purpose of ascertaining this, I imagine my expectations are not likely to be disappointed - My only fear was that India rubber would not bear the action of nitric acid but I find it was groundless - I have boiled a sheet of caoutchouc in a mixture of equal parts of nitric acid of commerce and water - with no other result that of having imparted a slight brown tint to fluid - A friend of mine who has recently commenced the manufacture of India Rubber says there would be no mechanical difficulty in forming these troughs - Of course the India rubber will merely constitute the lining of the apparatus[.]

I have promised my friend that I will do all in my power to secure to him the exclusive manufacture of these troughs if they should ever become general. He says that provided you should wish to try a trough of this kind, he will have great pleasure in covering a wooden trough if you think proper to send it - His name and address are J.C. Ward² | 33 Gt St. Helens | Bishopsgate St - to which place I should thank you to address any answer to this letter that you may think proper[.]

I am Sir | Yours most respectfully | W. Saffern