One of the many useful properties of giant nerve fibres is that samples of protoplasm or axoplasm as it is usually called can be obtained by squeezing out the contents from a cut end ... As in many other cells there is a high concentration of potassium ions and relatively low concentration of sodium and chloride ions. This is the reverse of the situation in the animals' blood or in sea water, where sodium and chloride are the dominant ions and potassium is relatively dilute.

When [Humphry Davy] saw the minute globules of potassium burst through the crust of potash, and take fire as they entered the atmosphere, he could not contain his joy—he actually bounded about the room in ecstatic delight; some little time was required for him to compose himself to continue the experiment.

[Davy's] March of Glory, which he has run for the last six weeks—within which time by the aid and application of his own great discovery, of the identity of electricity and chemical attractions, he has placed all the elements and all their inanimate combinations in the power of man; having decomposed both the Alkalies, and three of the Earths, discovered as the base of the Alkalies a new metal... Davy supposes there is only one power in the world of the senses; which in particles acts as chemical attractions, in specific masses as electricity, & on matter in general, as planetary Gravitation... when this has been proved, it will then only remain to resolve this into some Law of vital Intellect—and all human knowledge will be Science and Metaphysics the only Science.
In November 1807 Davy gave his famous Second Bakerian Lecture at the Royal Society, in which he used Voltaic batteries to 'decompose, isolate and name' several new chemical elements, notably sodium and potassium.