JUSTIN RUSSELL Tulane University, New Orleans, Louisiana
Mum has been written of the brilliant
work of Hnmphry Davy, and in some accounts of his contributions to the development of chemistry in the early nineteenth century he has been given credit for investigations that were carried out by his less well-known cousin, Edmund Davy. Dr. John Davy, brother of Humphry, and Edmund Davy were extravagant in their praise of this unique genius so closely related to them. This admiration is not surprising for Humphry Davy had generously helped hoth of them to achieve success in their nork. I t might be of interest to note that neither Paris nor John Davy mention Edmund Davy in their lives of Sir Humphry Davy.' Edmund Davy, son of William Davy, was horn a t Penzance, in Cornn.all, in 1785, where he ohtained his early e d u c a t i o ~ . ~Humphry Davy "-as seven years older than Edmund, and had heen professor of chemist,ry a t the Royal Institution for ahnost three years when he used his influence to have Edmund appointed operator and assistant in the lahoratory. The elder Davy demanded close attention to order in the lahoratory from his assistants although he generally neglected this detail himself. Edmnnd Davy remained in London vith the Royal Institution from 1804 until 1813. He was also the superintendent of the mineralogical collection of the Royal Instit,ution. The young man vas, no doubt, present as the assistant a t many of the very popular Friday evening lectures of Humphry Davy, four of which mere attended by Michael Faraday in the spring of 1812. Faraday, it i l l he remembered, also through tthe influence of Humphry Davy, received an appointment a t the Royal Institution as an assistant. These lectures, open to the public, made an impression on Edmund Davy which he carried with him after he left the Royal Institution, for he used his inflnence later to establish popular courses of lectures in most of the Irish provinces. In 1813 Edmund n a v y van maminously elected professor a t t,he Royal Cork Institution, possibly through the influence of Humphry Davy ~ v h ohad delivered a coursc of lectures in Dublin t,wo years previously. In 1826, he became professor of chemistry of the Royal Dublin Society. He remained in Dnhlin until his retirement. He died on November 5, 1857, ten years hefore the death of Michael Faraday. During his lifetime, Edmund Davy was overnhadowed bv Humuhrv Davv. the toast of scientific PARIS,J. A., "Life of Siv Hun~phryDavy," Colbunl, London, 1831. Davy, JOHN,"hl~moirsof the Life of Sir Humphry Davy," Longman, Recs, Ormo, Rrom, Green & Langman, London, 1836, 2 vols. "Dictionary of National Riogl~~phv," Smith, Elder & Co., I~ondon,1888, Vol. 14, p. 185.
circles in London and on the continent, and by John Davy, world traveler in government service. Humphry Davy must have appeared much a s a hero to Edmund and for most of his lift he followed in the path of his cousin. Many of his investigations were centered around the ideas of Humphry Davy and &,hen he thought that his experiments substantiated claims made by Humphry, he did not hesitate to say so. In 1812, while he was still a t the Royal Institution, his first three papers were published, two of which were concerned with platinum, an elenent investigated concurrently hy Humphry Davy. Both of the men puhlished papers that year dealing with sulfur and phosphorus. Edmnnd Davy is probably hest known as the discoverer of acetylene although he ohtained it in an impure state as a b y - p r o d ~ c t . ~In January of 1836 he was trying to prepare pure potassium by heating to a high temperature pulverized carbon with tartar (potassium hydrogen tartrate). From this he ohtained a graybrown mass which he treated with water and noted t,he evolution of a gas.4 He showed the gas to he a compound of carhon and hydrogen and noted its burning with a brilliant flame, and its rapid reaction tvhen hrought in contact with chlorine. He proposed that the gas rvas formed out of a compound of potassium and carhon in the residue obtained by the heating process.> Although he correctly determined the carbon to hydrogen ratio of the gas, he did not establish its definite structure, nor did he give it its present name. This was left to Berthelot who, a quarter of a rentury later, showed that it can be ohtained by the direct comhination of carhon and hydrogen a t the temperature of the electric arc, as well as in other ways. Calcium carbide, which is n s ~ ~ a lassociated ly n-ith the preparation of acetylene, was first prepared in 1840, four years after thr work of Davy. Much of Edmund Davy's early work was done with platinum and its compounds, and in this he mas folloiving a line of study closely related to that of H u m p h y Davy. In hisdiscovery of the safety lamp in 1817, thr elder n a v y had come to the conclusion that in t h ~ presence of air a platinum wire through contart \x-it,ll the vapor of alcohol or ether, a t temperatnres heloiv thr a \YAWS, H. A,, "A Dictiomry of Chemistry," Longmsni;. Green & Co., London, 1883, p. 11 11. ~ E B I O J., , Ann., 23,144 (1837). T h e paper noting this discovery is lifited in the Royal Society London, 1868, Catdologue of Scientific Papers, C. J. Clay & SOIIPI, p. 169, as heing titled, "Notice of a new gaseous hicarburct of hydrogen, and of a peculiw troompound of carhon and pota~sium or carhuret of potassium." This paper 3 r . z ~ publishrd in Brit. Assor. Rep., 1836, Pt. 2, pp. 62-4.
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ignition temperatures, can become glowing and that an acid is formed. He charged Faraday to determine the certainty of this. Faraday found this acid to be acetic acid. Daniell also analyzed this acid by the method of Gay-Lussac and Thenard and versed Faraday's findines.6 At about the same time. Edmuud Davv. " * in a published report, stated that a ;reparation of platinum made by him, which he called fulminating platinum, possessed the remarkable property, a t ordinary temperatures, of making wine spirit (ethyl alcohol) glow so strongly that it ignited.' Oxidation of the alcohol to acetic acid took place so rapidly a t the surface of the platinum that the latter was raised to incandescence: While a t the Cork Institution he reacted platinum sulfate with alcohol and ~roduceda black ~ o w d e which r appeared to consist almost entirely of platinum. This powder reacted with alcohol vapor, and he found that ". . .the acid first noticed by Sir Humphry Davy (in his beautiful experiment of the ignited platinum wire, and since, more fully examined by Mr. Daniell) is produced." Davy then constructed a tinder-box, ". . .to procure immediate light by means of the powder." He also prepared an oxide of platinum and found it to be insoluble in aqua regia, ". . .a fact which seems to add additional support to Sir H. Davy's opinion respecting the action of aqua regia on p l a t i n ~ m . " ~Sir Humphry Davy had been of the opinion that aqua regia did not form an oxide with platinum when the metal was dissolved, but merely caused its combination with chlorine. Edmund Davy stated that his findings supported Humphry Davy's claims, a matter in which they were correct. Platinum is dissolved by . aaua - repia, formine PtC1,. Dobereiner continued the investigation on the remarkable effects produced by platinum sponge and due to his interesting and spectacular demonstrations called the attention of chemists to the use of this form of platinum.9 In 1821, Dobereiner showed that platinum black causes alcohol to combine with the oxygen of the air to form acetic acid and a product which he called "oxygen ether." Liebig later isolated acetal and acetaldehyde from this "oxygen ether." Dobereiner made an important discovery when he found that spongy platinum has the property of setting fire to a mixture of hydrogen and oxygen a t low temperatures. Using this principle, he constructed a lighter which was popular until the advent of phosphorus matches. In 1819, Edmund Davy published a paper on the solid excrement of the boa constrictor, in which he showed the existence of uric acid, although he was aware of the fact that Dr. Prout had previously discovered the presence of the acid in the boa excrement.1° This paver, . . . however, followed closely in time a similar work GEAEBE, C., "Geschichte der orgmisehen Chemie," Springer-
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Verlctg, Berlin, 1920, Vol. 1, p. 40. DAVY, E., Phil. Mag., 56,332 (1820). Ibid., p. 340. P~ANDTL, W., "Johann Wolfgmg Dehereiner, Goethe's Chemied Adviser." J. CHEM. EDUC.. 27. 176 (1950). 10 DAYY, E., ~ h i lMag., . 54,3034 (1819).
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by John Davy and shows the attention which he gave to the work of his distinguished cousins. He turned his attention to iodine and studied its action on various oils, including turpentine and lavender, linseed, olive, and castor oils. From this he concluded that. ". . .the action of iodine on volatile and fixed oils resembles that of chlorine on these bodies, a circumstance which serves to extend the analogies which Sir H. Davy has traced between iodine and chlorine in their chemical agencies.'"' Davy published several articles on qualitative tests for the metals, including manganese and arsenic, and on the applications of electrochemistry. While a t the Cork Institution, he suspected that the air of the Fever Hospitals might be impure and undertook experiments designed to discover if the composition of the air in the hospitals, devoid of proper ventilation, might he different from ordinary air. All of his experiments gave the composition of the air as the same as uncontaminated air, a fact which he definitely did not expect to find. He made some experiments on the buoys in Kingstown Harbour in order to try to find a method of protecting them from the action of sea water. Always a favorite study with Davy was the application of chemistry to agriculture. In 1817, while studying the inferior crop of wheat produced the previous year, he arrived a t the conclusion that ". ..the bad qualities of the new flour were connected with the production of saccharine matter i n the grain."12 He experimented with the hard water a t Black Rocks, near Cork, and advised the residents as to how it could be made more applicable to domestic uses. He made a comparative study of the value of Irish and Virginia tobacco, and some experiments to detect and prevent frauds in the sale of skimmed milk. To aid the farmers of his district, he made many studies of the value of peat, charcoal, and lime as deodorizing agents. "An Essay on the Use of Peat or Turf as a Means of Promoting the Public Health and the Agriculture of the United Kingdom," was published for h i by Hodges and Smith of Dublin in 1850. Shortly after he became professor of chemistry of the Royal Dublin Society in 1826, he was elected a fellow of the Royal Society of London, a fellow of the Chemical Society of London, and an honorary member of the SociM Franpise Statistique Universelle. During his life as a teacher and experimenter, he was always keenly interested in the spreading of chemical knowledge, and helped establish popular courses of lectures in the provinces, this idea being based on the enthusiasm with which the public lectures at the Royal Institution in London had been received. He personally gave more than 30 courses of lectures on chemical subjects, selecting especially subjects relating to applications of chemistry to agriculture. Davy published 33 papers between 1812 and 1857, although the "Royal Society Catalogue of Scientific Papers" credits him with only 30 papers. When the E., Phil. Mag., 59,20M1(1822). DAVY, 'WALVY, E., Phil. Mag., 49, 173 (1817). ~
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government was changing the constitution of the Irish ricientific societies, it recognized Davy's claims, by awarding him his entire salary upon retirement from his official ~osition. The Roval Dublin Societv reouested him to continue the portion of his duties &ich related to agricultural chemistry after his retirement. After June of 1856 Edmund Davy suffered from ill-health
JOURNAL OF CHEMICAL EDUCATION
until his death the following year a t Kimmage Lodge, County Dublin. ACKNOWLEDGMENT
The author, a graduate student, wishes to thank Dr. Clara deMilt for suggesting the topic of this paper and for correcting the manuscript.
