Edmund Davy
Encyclopedia
Edmund Davy FRS was a professor of Chemistry
at the Royal Cork Institution
from 1813 and professor of chemistry at the Royal Dublin Society
from 1826. He discovered acetylene
, as it was later named by Marcellin Berthelot
. He was also an original member of the Chemical Society
, and a member of the Royal Irish Academy
.
of Humphry Davy
, the famous chemist who invented the Davy lamp
for the safety of miners.
Edmund, the son of William Davy, was born in Penzance
, Cornwall
, and lived there throughout his teen years. He moved to London in 1804 to spend eight years as operator and assistant to Humphry Davy in the Royal Institution
laboratory, which he kept in order. For a large part of that time, Edmund was also superintendent of the Royal Society
's mineralogical collection. When, in October 1807, Humphry accomplished the electrolytic preparation of potassium
and saw the minute globules of the quicksilver-like metal burst through the crust and take fire, Edmund described that his cousin was so delighted with this achievement that he danced about the room in ecstasy.
Humphry Davy's younger brother, Dr. John Davy
, (24 May 1790 - 24 Jan 1868) also was a chemist who spent some time (1808–1811) assisting Humphry in his chemistry research at the Royal Institution. John was the first to prepare and name phosgene
gas.
Edmund William Davy (born in 1826), son of Edmund Davy, became professor of medicine in the Royal College, Dublin, in 1870. That they cooperated in research is shown in a notice to the Royal Irish Academy on the manufacture of sulphuric acid which Edmund Davy ends with an acknowledgement of the assistance he received in his experiments given by his son, Edmund William Davy.
with remarkable gas absorptive properties. Justus Liebig later prepared this in a purer form able to absorb up to 250 times its volume of oxygen
gas. Further, Edmund Davy discovered that even at room temperature, finely divided platinum would light up from heat in the presence of a mixture of coal gas
and air. In another such experiment, in 1820, he found that with the platinum, alcohol vapours were converted to acetic acid. (Humphry Davy had discovered a few years earlier that a hot platinum wire lit up in a mixture of coal gas and air.) This release of energy from oxidation of the compounds, without flame, and without change in the platinum itself, was a sign of the catalytic property of platinum investigated later by Johann Döbereiner and other chemists.
blocks would prevent corrosion
of the iron
structure of buoy
s.
In the Report of the British Association for 1835 he was the first to publish a series of experiments investigating the protective power of zinc employed in simple contact and in massive form. Shortly thereafter a French engineer, M. Sorel, secured a patent for a process of coating an iron surface with fluid zinc to protect against rust, and the technique was adopted by manufacturers of galvanized iron. Davy claimed priority of discovery, but it was found that a patent
had long before been issued, on 26 September 1791 to Madame Leroi de Jancourt for the protection of metals with a coating of an alloy of zinc, bismuth and tin (though without a knowledge of the chemical principles involved).
This is an example of cathodic protection
, an electrochemical technique developed in 1824 by Humphry Davy to prevent galvanic corrosion. He had recommended that the Admiralty
should attach iron blocks to protect the copper
sheathing on the hulls of Navy vessels. (The method was shortly discontinued because of an unfortunate side effect - the speed of the ships was reduced by increased fouling by marine life. The protective method reduced the release of copper ions that had otherwise poisoned the organisms and controlled their growth.)
, as a test of the presence of poisonous substances in cases of suspected poisoning. He applied a current
of electricity to precipitate the salts of various metallic poisons from a prepared solution. The method was valuable because the result was not affected by the presence of organic matter from the contents of the stomach. When used as a test, Davy claimed that the presence of only 1/2500th part of a grain of arsenic
could be discovered.
metal. By heating potassium carbonate with carbon at very high temperatures, he produced a residue of what is now known as potassium carbide, (K2C2), which reacted with water to release the new gas. (A similar reaction between calcium carbide
and water was subsequently widely used for the manufacture of acetylene
.)
In the paper he read to the British Association at Bristol, Davy anticipated the value of acetylene as an illuminating gas: "From the brilliance with which the new gas burns in contact with the atmosphere it is, in the opinion of the author, admirably adapted for the purpose of artificial light, if it can be procured at a cheap rate."
Thereafter it was forgotten until Marcellin Berthelot
rediscovered this hydrocarbon
compound in 1860, for which he coined the name "acetylene
."
. In some of his own lectures at the Royal Dublin Society, Davy showed his special interest in the applications of chemistry in agriculture
. He published several papers concerning manure
s and chemical aids useful to farmers. These included "An Essay on the Use of Peat or Turf as a Means of Promoting Public Health and the Agriculture of the United Kingdom" (1850), and "An account of some Experiments made to determine the relative deodorizing Powers of Peat-charcoal, Peat, and Lime" (1856).
He also studied the uptake of arsenic by crops from artificial manures chemically prepared with sulphuric acid in which it was not usual to have arsenic as an impurity. Testing the growth of plants, he found "that arsenic might be taken up in considerable quantities by plants without destroying their vitality, or appearing even to interfere with their proper functions." He understood that arsenic was an accumulative poison
, and that with continued consumption the "substance may collect in the system till its amount may exercise an injurious effect on the health of men and animals."
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
at the Royal Cork Institution
Royal Cork Institution
Royal Cork Institution was an Irish cultural institution in the city of Cork from 1803-1885. It consisted of a library of scientific works, a museum with old Irish manuscripts and stones with ogham inscriptions, and lecture and reading rooms. A lack of funds resulted in its closure in...
from 1813 and professor of chemistry at the Royal Dublin Society
Royal Dublin Society
The Royal Dublin Society was founded on 25 June 1731 to "to promote and develop agriculture, arts, industry, and science in Ireland". The RDS is synonymous with its main premises in Ballsbridge in Dublin, Ireland...
from 1826. He discovered acetylene
Acetylene
Acetylene is the chemical compound with the formula C2H2. It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in pure form and thus is usually handled as a solution.As an alkyne, acetylene is unsaturated because...
, as it was later named by Marcellin Berthelot
Marcellin Berthelot
Marcelin Pierre Eugène Berthelot was a French chemist and politician noted for the Thomsen-Berthelot principle of thermochemistry. He synthesized many organic compounds from inorganic substances and disproved the theory of vitalism. He is considered as one of the greatest chemists of all time.He...
. He was also an original member of the Chemical Society
Chemical Society
The Chemical Society was formed in 1841 as a result of increased interest in scientific matters....
, and a member of the Royal Irish Academy
Royal Irish Academy
The Royal Irish Academy , based in Dublin, is an all-Ireland, independent, academic body that promotes study and excellence in the sciences, humanities and social sciences. It is one of Ireland's premier learned societies and cultural institutions and currently has around 420 Members, elected in...
.
Family and early life
Edmund Davy was a cousinCousin
In kinship terminology, a cousin is a relative with whom one shares one or more common ancestors. The term is rarely used when referring to a relative in one's immediate family where there is a more specific term . The term "blood relative" can be used synonymously and establishes the existence of...
of Humphry Davy
Humphry Davy
Sir Humphry Davy, 1st Baronet FRS MRIA was a British chemist and inventor. He is probably best remembered today for his discoveries of several alkali and alkaline earth metals, as well as contributions to the discoveries of the elemental nature of chlorine and iodine...
, the famous chemist who invented the Davy lamp
Davy lamp
The Davy lamp is a safety lamp with a wick and oil vessel burning originally a heavy vegetable oil, devised in 1815 by Sir Humphry Davy. It was created for use in coal mines, allowing deep seams to be mined despite the presence of methane and other flammable gases, called firedamp or minedamp.Sir...
for the safety of miners.
Edmund, the son of William Davy, was born in Penzance
Penzance
Penzance is a town, civil parish, and port in Cornwall, England, in the United Kingdom. It is the most westerly major town in Cornwall and is approximately 75 miles west of Plymouth and 300 miles west-southwest of London...
, Cornwall
Cornwall
Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...
, and lived there throughout his teen years. He moved to London in 1804 to spend eight years as operator and assistant to Humphry Davy in the Royal Institution
Royal Institution
The Royal Institution of Great Britain is an organization devoted to scientific education and research, based in London.-Overview:...
laboratory, which he kept in order. For a large part of that time, Edmund was also superintendent of the Royal Society
Royal Society
The Royal Society of London for Improving Natural Knowledge, known simply as the Royal Society, is a learned society for science, and is possibly the oldest such society in existence. Founded in November 1660, it was granted a Royal Charter by King Charles II as the "Royal Society of London"...
's mineralogical collection. When, in October 1807, Humphry accomplished the electrolytic preparation of potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
and saw the minute globules of the quicksilver-like metal burst through the crust and take fire, Edmund described that his cousin was so delighted with this achievement that he danced about the room in ecstasy.
Humphry Davy's younger brother, Dr. John Davy
John Davy (chemist)
John Davy FRS was a British doctor, amateur chemist, and brother of the noted chemist Sir Humphry Davy, and cousin of Edmund Davy....
, (24 May 1790 - 24 Jan 1868) also was a chemist who spent some time (1808–1811) assisting Humphry in his chemistry research at the Royal Institution. John was the first to prepare and name phosgene
Phosgene
Phosgene is the chemical compound with the formula COCl2. This colorless gas gained infamy as a chemical weapon during World War I. It is also a valued industrial reagent and building block in synthesis of pharmaceuticals and other organic compounds. In low concentrations, its odor resembles...
gas.
Edmund William Davy (born in 1826), son of Edmund Davy, became professor of medicine in the Royal College, Dublin, in 1870. That they cooperated in research is shown in a notice to the Royal Irish Academy on the manufacture of sulphuric acid which Edmund Davy ends with an acknowledgement of the assistance he received in his experiments given by his son, Edmund William Davy.
Spongy platinum
Edmund Davy was the first to discover a spongy form of platinumPlatinum
Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...
with remarkable gas absorptive properties. Justus Liebig later prepared this in a purer form able to absorb up to 250 times its volume of oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
gas. Further, Edmund Davy discovered that even at room temperature, finely divided platinum would light up from heat in the presence of a mixture of coal gas
Coal gas
Coal gas is a flammable gaseous fuel made by the destructive distillation of coal containing a variety of calorific gases including hydrogen, carbon monoxide, methane and volatile hydrocarbons together with small quantities of non-calorific gases such as carbon dioxide and nitrogen...
and air. In another such experiment, in 1820, he found that with the platinum, alcohol vapours were converted to acetic acid. (Humphry Davy had discovered a few years earlier that a hot platinum wire lit up in a mixture of coal gas and air.) This release of energy from oxidation of the compounds, without flame, and without change in the platinum itself, was a sign of the catalytic property of platinum investigated later by Johann Döbereiner and other chemists.
Corrosion
In 1829, Edmund Davy found that the use of zincZinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
blocks would prevent corrosion
Corrosion
Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...
of the iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
structure of buoy
Buoy
A buoy is a floating device that can have many different purposes. It can be anchored or allowed to drift. The word, of Old French or Middle Dutch origin, is now most commonly in UK English, although some orthoepists have traditionally prescribed the pronunciation...
s.
In the Report of the British Association for 1835 he was the first to publish a series of experiments investigating the protective power of zinc employed in simple contact and in massive form. Shortly thereafter a French engineer, M. Sorel, secured a patent for a process of coating an iron surface with fluid zinc to protect against rust, and the technique was adopted by manufacturers of galvanized iron. Davy claimed priority of discovery, but it was found that a patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
had long before been issued, on 26 September 1791 to Madame Leroi de Jancourt for the protection of metals with a coating of an alloy of zinc, bismuth and tin (though without a knowledge of the chemical principles involved).
This is an example of cathodic protection
Cathodic protection
Cathodic protection is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell. The simplest method to apply CP is by connecting the metal to be protected with another more easily corroded "sacrificial metal" to act as the anode of the...
, an electrochemical technique developed in 1824 by Humphry Davy to prevent galvanic corrosion. He had recommended that the Admiralty
Admiralty
The Admiralty was formerly the authority in the Kingdom of England, and later in the United Kingdom, responsible for the command of the Royal Navy...
should attach iron blocks to protect the copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
sheathing on the hulls of Navy vessels. (The method was shortly discontinued because of an unfortunate side effect - the speed of the ships was reduced by increased fouling by marine life. The protective method reduced the release of copper ions that had otherwise poisoned the organisms and controlled their growth.)
Electrochemistry
Edmund Davy made a series of experiments to detect the presence of metallic poisons by means of electricityElectricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
, as a test of the presence of poisonous substances in cases of suspected poisoning. He applied a current
Electric current
Electric current is a flow of electric charge through a medium.This charge is typically carried by moving electrons in a conductor such as wire...
of electricity to precipitate the salts of various metallic poisons from a prepared solution. The method was valuable because the result was not affected by the presence of organic matter from the contents of the stomach. When used as a test, Davy claimed that the presence of only 1/2500th part of a grain of arsenic
Arsenic
Arsenic is a chemical element with the symbol As, atomic number 33 and relative atomic mass 74.92. Arsenic occurs in many minerals, usually in conjunction with sulfur and metals, and also as a pure elemental crystal. It was first documented by Albertus Magnus in 1250.Arsenic is a metalloid...
could be discovered.
Acetylene
In 1836, Edmund Davy discovered a gas which he recognised as "a new carburet of hydrogen." It was an accidental discovery while attempting to isolate potassiumPotassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
metal. By heating potassium carbonate with carbon at very high temperatures, he produced a residue of what is now known as potassium carbide, (K2C2), which reacted with water to release the new gas. (A similar reaction between calcium carbide
Calcium carbide
thumb|right|Calcium carbide.Calcium carbide is a chemical compound with the chemical formula of CaC2. The pure material is colorless, however pieces of technical grade calcium carbide are grey or brown and consist of only 80-85% of CaC2 . Because of presence of PH3, NH3, and H2S it has a...
and water was subsequently widely used for the manufacture of acetylene
Acetylene
Acetylene is the chemical compound with the formula C2H2. It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in pure form and thus is usually handled as a solution.As an alkyne, acetylene is unsaturated because...
.)
In the paper he read to the British Association at Bristol, Davy anticipated the value of acetylene as an illuminating gas: "From the brilliance with which the new gas burns in contact with the atmosphere it is, in the opinion of the author, admirably adapted for the purpose of artificial light, if it can be procured at a cheap rate."
Thereafter it was forgotten until Marcellin Berthelot
Marcellin Berthelot
Marcelin Pierre Eugène Berthelot was a French chemist and politician noted for the Thomsen-Berthelot principle of thermochemistry. He synthesized many organic compounds from inorganic substances and disproved the theory of vitalism. He is considered as one of the greatest chemists of all time.He...
rediscovered this hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
compound in 1860, for which he coined the name "acetylene
Acetylene
Acetylene is the chemical compound with the formula C2H2. It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in pure form and thus is usually handled as a solution.As an alkyne, acetylene is unsaturated because...
."
Chemistry in agriculture
Davy was active in promoting scientific knowledge, whereby popular courses of lectures were established throughout IrelandIreland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
. In some of his own lectures at the Royal Dublin Society, Davy showed his special interest in the applications of chemistry in agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...
. He published several papers concerning manure
Manure
Manure is organic matter used as organic fertilizer in agriculture. Manures contribute to the fertility of the soil by adding organic matter and nutrients, such as nitrogen, that are trapped by bacteria in the soil...
s and chemical aids useful to farmers. These included "An Essay on the Use of Peat or Turf as a Means of Promoting Public Health and the Agriculture of the United Kingdom" (1850), and "An account of some Experiments made to determine the relative deodorizing Powers of Peat-charcoal, Peat, and Lime" (1856).
He also studied the uptake of arsenic by crops from artificial manures chemically prepared with sulphuric acid in which it was not usual to have arsenic as an impurity. Testing the growth of plants, he found "that arsenic might be taken up in considerable quantities by plants without destroying their vitality, or appearing even to interfere with their proper functions." He understood that arsenic was an accumulative poison
Poison
In the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....
, and that with continued consumption the "substance may collect in the system till its amount may exercise an injurious effect on the health of men and animals."