The bubbles of gas liberated on one of the platinum plates or wires of a decomposing cell are always much smaller, and they rise in much more rapid succession than those from the other.

Knowing that oxygen is sixteen times heavier than hydrogen, I have more than once concluded, and, I fear, led others into the error of concluding, that the smaller and more quickly rising bubbles must belong to the lighter gas.

The thing appeared so obvious that I did not give myself the trouble of looking at the battery, which would at once have told me the nature of the gas.

But Faraday would never have been satisfied with a deduction if he could have reduced it to a fact.

And he has taught me that the fact here is the direct reverse of what I supposed it to be.