The voltaic current passing through a solution of this salt so decomposes it, that sulphuric acid appears at one pole of the decomposing cell and alkali at the other.

Faraday steeped a piece of litmus paper and a piece of turmeric paper in a solution of sulphate of soda: placing each of them upon a separate plate of glass, he connected them together by means of a string moistened with the same solution.
He then attached one of them to the positive conductor of an electric machine, and the other to the gas-pipes of this building.

These he called his 'discharging train.' On turning the machine the electricity passed from paper to paper through the string, which might be varied in length from a few inches to seventy feet without changing the result.
The first paper was reddened, declaring the presence of sulphuric acid; the second was browned, declaring the presence of the alkali soda.

The dissolved salt, therefore, arranged in this fashion, was decomposed by the machine, exactly as it would have been by the voltaic current.
When instead of using the positive conductor he used the negative, the positions of the acid and alkali were reversed.

Thus he satisfied himself that chemical decomposition by the machine is obedient to the laws which rule decomposition by the pile.
And now he gradually abolishes those so-called poles, to the attraction of which electric decomposition had been ascribed.