Humphry Davy, Poet and Philosopher

by T. E. Thorpe

The chemical laboratory of the Royal Institution, as the scene of Davy’s greatest discoveries—discoveries which mark epochs in the development of natural knowledge—will for ever be hallowed ground to the philosopher. The votaries of Hermes have raised far more stately temples: to-day they follow their pursuit in edifices which in architectural elegance and in equipment are palaces compared with the subterranean structure which lies behind the Corinthian façade in Albemarle Street. But to the chemist this spot is what the Ka’ba at Mecca is to the follower of Mohammed, or what Iona was to Dr. Johnson: and, if we may venture to adapt the language of the English moralist, that student has little to be envied whose enthusiasm would not grow warmer or whose devotion would not gain force within the place made sacred by the genius and labours of Davy and Faraday.

And yet, were these great men to revisit the scene of their triumphs, they would hardly recognise it, so completely altered is it by adaptations and rearrangements rendered necessary by their discoveries. How it appeared in their own time may be seen from the illustration on page [91], taken from a water-colour drawing by Miss Harriet Moore, in the possession of the Managers of the Royal Institution.

CHEMICAL LABORATORY OF THE ROYAL INSTITUTION IN DAVY’S TIME.

The first year of the century is memorable for the invention of the voltaic pile, and for the discovery, by Nicholson and Carlisle, on April 30th, 1800, of the electrolytic decomposition of water. As Davy said, “the voltaic battery was an alarm-bell to experimenters in every part of Europe; and it served no less for demonstrating new properties in electricity, and for establishing the laws of this science, than as an instrument of discovery in other branches of knowledge; exhibiting relations between subjects before apparently without connection, and serving as a bond of unity between chemical and physical philosophy.” The capital discovery of Volta was made known in England at the earliest possible moment through the mediation of Sir Joseph Banks, and the study of voltaic electricity, its effects and applications, was immediately afterwards entered upon by many Englishmen of science with great zeal and ardour. Davy at this time had just completed his work on Nitrous Oxide; and, powerfully impressed with the significance of Nicholson and Carlisle’s observation, he at once turned his attention to the subject, and even before leaving Bristol he had sent a number of short papers on what was then usually termed the galvanic electricity to Nicholson’s Journal. He showed that oxygen and hydrogen were evolved from separate portions of water, though vegetable and even animal substances intervened; and conceiving that all decomposition might be polar, he “electrised” different compounds at the different extremities, and found that sulphur and metallic substances appeared at the negative pole, and oxygen and nitrogen at the positive pole, though the bodies furnishing them were separate from each other. The papers, however, are mainly remarkable for the fact that they served to establish the intimate connection between the electrical effects and the chemical changes going on in the pile, and for the conclusion drawn concerning their mutual dependence. Within a few days after his removal to the Royal Institution he resumed his inquiries, publishing his results in a series of notices in the short-lived Journal of the Royal Institution.

In 1801 he sent his first communication to the Royal Society, on “An Account of some Galvanic Combinations, formed by the Arrangement of single metallic Plates and Fluids, analogous to the new Galvanic Apparatus of Mr. Volta.”

But at this period, and for some time afterwards, Davy was not altogether free to develop his own ideas, as the work of the laboratory was controlled by a committee which met, from time to time, to deliberate and settle upon the researches which were to be undertaken by their Professor. As we have seen, he was requested, in the first place, to turn his attention to tanning, and to investigate the astringent principles employed in the manufacture of leather. Afterwards, when the Managers determined to form a mineralogical collection, and to institute an assay office for the improvement of mineralogy and metallurgy, he was ordered to make analyses of rocks and minerals. And lastly, in consequence of an arrangement between the Managers and the Board of Agriculture, effected by Arthur Young, he was required to take up the subject of Agricultural Chemistry. To a man of Thomas Young’s temperament the fussy activity of committees, directed by such people as Bernard and Hippesley, would have been resented as an irksome, if not intolerable, interference; but Davy invariably acted as if he considered that their decisions promoted the true interests of the Institution, and entered with ardour into each new scheme. There was no irksomeness to him in being called upon to change the current of his ideas, for he delighted in the opportunity of exhibiting his versatility; and, confident in his powers, he had the ambition to touch everything in turn, and to adorn it. That he should have succeeded so well under such conditions is perhaps the strongest evidence that could be adduced of the strength and elasticity of his eager, active mind, and of his astonishing power of rapid, well-directed work.

We have already dealt with his researches in connection with tanning. The efforts of the Managers towards the improvement of mineralogy and metallurgy, in spite of the generous assistance of Mr. Greville, Sir J. St. Aubin, and Sir A. Hume, and the “activity and intelligence of Mr. Davy,” proved abortive.

One outcome of Davy’s association with the matter may be seen in his paper, published by the Royal Society in 1805, on “An Account of some analytical Experiments on a mineral Production from Devonshire, consisting principally of Alumine and Water.” The mineral referred to was discovered by Dr. Wavel in an argillaceous slate near Barnstaple, and hence was termed wavellite. Davy failed to recognise its true nature, which was first correctly ascertained by Berzelius. A few weeks later, he sent to the Royal Society a second paper “On a Method of Analyzing Stones containing fixed Alkali, by Means of the Boracic Acid.” The method, however, is of comparatively limited application, and is seldom, if ever, now used in analysis. Determinative chemistry was never one of Davy’s strong points, and few of his analytical processes are now employed. Patient manipulation, and minute and sustained attention to detail, were altogether foreign to his disposition and habits, although he had the highest appreciation of these qualities in men like Cavendish and Wollaston.

The lectures on agriculture however, were a great success, and brought increased fame and no small profit to the lecturer. His association with the Board of Agriculture developed into a permanent appointment; for ten successive years he continued to lecture on the subject before its members, and in 1813 he put together the results of his labours in his well-known “Elements of Agricultural Chemistry.” In simplicity and absence of ornament the style of these lectures is in marked contrast to that which he usually employed at the Royal Institution. Dealing with men to whom the matter was of paramount importance, he had no need to stimulate their interest by the arts he employed in the theatre in Albemarle Street. The very nature of the subject, perhaps, served to remind him that tropes and metaphors were here as much out of place as “the brilliant wild flowers in the field of corn—very pretty, but which did very much hurt the corn.”