London: Richard Taylor, 1808. 1st Edition. SECOND PUBLICATION OF “ONE OF THE GREAT CLASSIC RESEARCHES IN CHEMISTRY” – DAVY’S ISOLATION & DISCOVERY OF POTASSIUM AND SODIUM (Neville, Historical Chemical Library, I, p. 340). Davy first presented this work as his Bakerian Lecture before the Royal Society, hence its first publication in The Philosophical Transactions in 1808. This publication in the Philosophical Magazine also appeared in 1808. Davy’s lecture, presented here in 3 parts, includes profuse detail on the entirety of his work, post 1800, on the chemical effecsts of electricity.
Sir Humphry Davy was a brilliant Cornish chemist and inventor who was a pioneer in the use of electrochemistry and one of the foremost leaders of Lavoisier’s movement to reform chemistry in the late 18th century. Until the mid-20th century, Davy “held the record for discovering the most chemical elements” (Greenberg, A Chemical History Tour, 183).
In 1800, Volta had introduced the first battery and Davy grew interested in studying electroscience, or electricity’s effect on chemical reactions. In his lab, Davy used Volta’s battery to preform electrolysis – or to decompose chemical compounds by passing an electric current from the battery and through the elements. He found the method particularly useful for breaking down compounds too stable to break apart through the application of heat or use of chemical reactions.
“In 1807, Davy applied himself to a problem that had vexed Lavoisier, who was convinced that potash was a compound even though it resisted ‘simplification’. He employed a huge, more powerful, voltaic pile (his ‘battery of the power of 250 of 6 and 4’ – seemingly a pile of 150 pairs of 4-inch square plates connected to a pile of 100 pairs of 6-inch square plates). His attempts to decompose aqueous solutions of potash merely electrolyzed water.
However, when a piece of solid potash was placed on a disk of platinum (connected to the negative pole) and a platinum wire (connected to the positive pole) was touched to the top of the potash, the solid fused at both points of contact. A violent effervescence at the upper surface (positive pole) was due to oxygen gas. At the lower part (platinum plate), beads of silvery mercury-like liquid appeared, some of which exploded and burned with a bright flame. According to his cousin Edmund Davy, then working as an assistant:
[When Humphry Davy] saw the 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; and some little time was required for him to compose himself sufficiently to continue the experiment.
In a few days, Davy had successfully isolated sodium” (ibid, 181-182). Today, sodium is extracted via the same method that Davy used over 200 years ago. Item #1609
CONDITION & DETAILS: London: Richard Taylor. 4to. , 378, . Eight plates. Ex-libris bearing a light stamp on ffp and three equally light on the title page. Bound in half calf over worn marbled paper boards, very scuffed at the edges. Text block is very tight; front board holding tightly by threads; rear board holding detached. The interior is bright and very clean.