Scientist of the Day - Humphry Davy
Columnar basal (16) and other rock formations, detail of idealized geologic landscape (our seventh image), engraving, Elements of Agricultural Chemistry, in a Course of Lectures for the Board of Agriculture, by Humphry Davy, fig. 16, 1813 (Linda Hall Library)
Humphry Davy, an English chemist, died May 29, 1829, at age 50, in Geneva. Davy is best known as a pioneer in electrolytic chemistry, where an electric current is used to break apart tightly-bound molecules, such as sodium chloride. Using the recently invented battery (1800) of Alessandro Volta, beginning around 1807, Davy disassociated sodium and chlorine for the first time, as well as potassium, calcium, boron, iodine, and more. We celebrated this part of Davy’s career in our first post on Davy.
Portrait bust of Humphry Davy, by Ruby Winifred Levick, ca 1900, copy of work made during Davy’s lifetime, Royal Institution, London (artuk.org)
Davy was professor of chemistry at the Royal Institution in London, and his chemistry lectures regularly drew audiences of 500 or more. Interestingly, he lectured on geology as well, and on agricultural chemistry. His geology lectures were not published in his lifetime, but those on agricultural chemistry fared better, perhaps because they were delivered on commission to the Board of Agriculture of Great Britain, which could afford to subsidize their publication.
Title page, Elements of Agricultural Chemistry, in a Course of Lectures for the Board of Agriculture, by Humphry Davy, 1813 (Linda Hall Library)
Davy's Elements of Agricultural Chemistry was published in 1813, and we have a copy in our History of Science Collections. I read through a considerable chunk of the book while writing this, because I was curious what Davy could say about a subject that was just beginning to be understood in 1810. But Davy does realize that plant growth depends on the nature of the soil, especially its acidity or alkalinity, and that plants require fixed air (carbonic acid, or carbon dioxide) and give off good air (oxygene, he calls it), and that the bulk of the atmosphere (nitrogen) has no effect on plant growth.
A variety of plants being grown under controlled conditions, engraving, Elements of Agricultural Chemistry, in a Course of Lectures for the Board of Agriculture, by Humphry Davy, fig. 17, foll. p. 197, 1813 (Linda Hall Library)
Davy did experiments in which a variety of meadow grasses and clovers were grown in a dish under a glass cover, where the addition of air, carbonic acid, and water could be closely controlled, and showed that when placed in sunlight, the plants improved the quality of the air (i.e., increased the level of oxygen). He provided an engraving of the experiment (fourth image).
Quarter of a horizontal section of an ash tree, engraving, Elements of Agricultural Chemistry, in a Course of Lectures for the Board of Agriculture, by Humphry Davy, fig. 10, foll. p. 54, 1813 (Linda Hall Library)
He showed three magnified sections of three species of tree (I show the slice from an ash tree, fifth image) and speculated on the function of the radial lines (which he called silver grain) and those that run perpendicular into the page (spurious grain) and allow one to measure a tree’s age. I have no idea how much of this had worthwhile explanatory value.
Effects of centrifugal force on seedings, engraving, Elements of Agricultural Chemistry, in a Course of Lectures for the Board of Agriculture, by Humphry Davy, figs. 1-2, foll p. 30, 1813 (Linda Hall Library)
He also knew about geotropism and devised an experiment showing that seedlings on a rotating wheel grow toward the axis and away from the "downward" or centrifugal force (sixth image).
Idealized geologic landscape, engraving by F.C. Bruce from a painting by Thomas Webster, Elements of Agricultural Chemistry, in a Co urse of Lectures for the Board of Agriculture, by Humphry Davy, fig. 16, foll. p. 172, 1813 (Linda Hall Library)
Davy’s longest chapter is on soil, which is not surprising, as farmers have known forever that soil quality is everything in agriculture, and that soils are easily depleted. Illustrating his chapter is an unexpected engraving (seventh image), showing an idealized geological landscape, populated by every possible kind of landform – igneous, metamorphic, sedimentary. It is unexpected because this is a book on agriculture by a chemist, and an idealized geological landscape would not seem to be called for. But Davy had commissioned the scene from Thomas Webster for his lectures on geology at the Royal Institution, and my guess is that Davy liked it a lot but had no place to publish it, so he stuck it here, and added enough explanatory text to justify its inclusion. It is said that Davy drew the initial sketch, and Webster turned it into a finished painting. Webster was an excellent geological artist and was then completing the engravings for Henry Englefield's A Description of the Principal Picturesque Beauties, Antiquities, and Geological Phaenomena of the Isle of Wight (1816; see our post on Englefield for examples of Webster's geological artwork).
Slightly cropped idealized geologic landscape (our seventh image), with captions, engraving, Elements of Agricultural Chemistry, in a Course of Lectures for the Board of Agriculture, by Humphry Davy, fig. 16, foll. p. 172, 1813 (Linda Hall Library)
There was really no precedent for an idealized geological landscape, at least none that I know of. If Davy did the initial sketch, then he gets the credit for inventing the genre. Perhaps these were in common use as wall charts for classroom instruction, but if they never appeared in print, it is hard for us to know. This one WAS printed, and since it is so unusual, we show, in addition to the full engraving (seventh image), a slightly cropped version with caption (eighth image), and a more heavily cropped version, in which you can see the columnar basalt such as that found at Fingal’s Cave and the Giant’s Causeway (no. 16). That forms our own frontispiece (first image).
Others have appreciated the unusual nature of Davy's idealized rocky landscape. When Noah Heringman wanted a frontispiece for his book on the impact of geology on Romantic poetry, called Romantic Rocks, Aesthetic Geology (Cornell Univ. Pr., 2004), he chose Davy's landscape. Indeed, he used our copy of Davy's book as his image source.
William B. Ashworth, Jr., Consultant for the History of Science, Linda Hall Library and Associate Professor emeritus, Department of History, University of Missouri-Kansas City. Comments or corrections are welcome; please direct to ashworthw@umkc.edu.
