History of chemistry

chemistryburgeoning chemistrychemical revolution
There had been many mining explosions caused by firedamp or methane often ignited by open flames of the lamps then used by miners. Davy conceived of using an iron gauze to enclose a lamp's flame, and so prevent the methane burning inside the lamp from passing out to the general atmosphere. Although the idea of the safety lamp had already been demonstrated by William Reid Clanny and by the then unknown (but later very famous) engineer George Stephenson, Davy's use of wire gauze to prevent the spread of flame was used by many other inventors in their later designs.

Gas lighting

gas lampgaslightgas light
Coal miners described two types of gases, one called the choke damp and the other fire damp. In 1667, a paper detailing the effects of these gases was entitled, "A Description of a Well and Earth in Lancashire taking Fire, by a Candle approaching to it. Imparted by Thomas Shirley, Esq an eye-witness." Stephen Hales was the first person who procured a flammable fluid from the actual distillation of coal. His experiments with this object are related in the first volume of his Vegetable Statics, published in 1726.

Outline of mining

MiningMining engineeringoutline
William Reid Clanny – inventor of the first safety lamp. Billy Elliot. Brassed Off. Centre for Mined Land Rehabilitation. European Route of Industrial Heritage. National Coal Mining Museum for England. National Mining Hall of Fame. Salt-concrete. Scientific drilling. Well drilling. Water mining. Mining Journal. Introduction to Mining. What is mining?.


Some miners were sent to work in an area of the colliery which was not free from firedamp and the men were expressly ordered to use safety lamps. One man, John Moody, ignored this instruction and was observed using a candle. The overman ordered Moody to extinguish the candle, which he did. Shortly afterwards Moody was again found using a candle and reprimanded. He extinguished the candle and lit his lamp. The overman had just left him when the explosion occurred. 38 of the 41 men underground were killed, including a grandfather, his two sons and seven grandsons. Two days later eight workmen descended Nova Scotia Pit, part of the same colliery.

Environmental impact of the coal industry

Environmental effects of coalCoal burningcoal pollution
Build-ups of a hazardous gas are known as damps: Firedamp explosions can trigger the much more dangerous coal dust explosions, which can engulf an entire pit. Most of these risks can be greatly reduced in modern mines, and multiple fatality incidents are now rare in some parts of the developed world. Modern mining in the US results in approximately 30 deaths per year due to mine accidents. Black damp: a mixture of carbon dioxide and nitrogen in a mine can cause suffocation. The anoxic condition results of depletion of oxygen in enclosed spaces, e.g. by corrosion.


More technical variants of manual strangulation are referred to as chokeholds, and are extensively practised and used in various martial arts, combat sports, self-defense systems, and in military hand-to-hand combat application. In some martial arts like judo and jujutsu, strangles or chokes that constrict blood flow are regarded as a safe way to render the opponent unconscious as opposed to other attacks, e.g. strikes to the head. During the 18th century, a sentence of "Death by Throttling" would be passed upon the verdict of a Court Martial for the crime of desertion from the British Army.

Geordie lamp

safety lampGeordie safety lampsminers' safety lamp
The Geordie lamp was a safety lamp for use in flammable atmospheres, invented by George Stephenson in 1815 as a miner's lamp to prevent explosions due to firedamp in coal mines. In 1815, Stephenson was the engine-wright at the Killingworth Colliery in Northumberland and had been experimenting for several years with candles close to firedamp emissions in the mine. In August he ordered an oil lamp which was delivered on 21 October and tested by him in the mine in the presence of explosive gases. He improved this over several weeks with the addition of capillary tubes at the base so that it gave more light and tried new versions on 4 and 30 November.

George Stephenson

In 1815, aware of the explosions often caused in mines by naked flames, Stephenson began to experiment with a safety lamp that would burn in a gaseous atmosphere without causing an explosion. At the same time, the eminent scientist and Cornishman Humphry Davy was also looking at the problem. Despite his lack of scientific knowledge, Stephenson, by trial and error, devised a lamp in which the air entered via tiny holes, through which the flames of the lamp could not pass.

Haldane effect

The Haldane effect is a property of haemoglobin first described by John Scott Haldane. Oxygenation of blood in the lungs displaces carbon dioxide from hemoglobin which increases the removal of carbon dioxide. This property is the Haldane effect. Consequently, oxygenated blood has a reduced affinity for carbon dioxide. Thus, the Haldane effect describes the ability of hemoglobin to carry increased amounts of carbon dioxide (CO 2 ) in the deoxygenated state as opposed to the oxygenated state. A high concentration of CO 2 facilitates dissociation of oxyhaemoglobin. Carbon dioxide can bind to amino groups, creating carbamino compounds.


gasesgaseousgaseous state
He identified carbon dioxide, the first known gas other than air. Van Helmont's word appears to have been simply a phonetic transcription of the Ancient Greek word χάος Chaos – the g in Dutch being pronounced like ch in "loch" (voiceless velar fricative, ) – in which case Van Helmont was simply following the established alchemical usage first attested in the works of Paracelsus. According to Paracelsus's terminology, chaos meant something like "ultra-rarefied water". An alternative story is that Van Helmont's word is corrupted from gahst (or geist), signifying a ghost or spirit.


In 1916, additional rulings were brought in to further limit kansetsu waza with the prohibition of ashi garami and neck locks, as well as do jime. These were further added to in 1925. The first time judo was seen in the Olympic Games was in an informal demonstration hosted by Kano at the 1932 Games. However, Kano was ambivalent about judo's potential inclusion as an Olympic sport: Nevertheless, judo became an Olympic sport for men in the 1964 Games in Tokyo. The Olympic Committee initially dropped judo for the 1968 Olympics, meeting protests. Dutchman Anton Geesink won the first Olympic gold medal in the open division of judo by defeating Akio Kaminaga of Japan.

Grappling hold

Katame-wazaheadlocksubmission hold
Anaconda choke: A type of arm triangle choke. Arm triangle choke: A chokehold similar to the triangle choke except using the arms. Crosschoke: Athlete crosses own arms in "X" shape and holds onto opponent's gi or clothing. Gi Choke: or Okuri eri jime as it is known in Judo is a single lapel strangle. Ezequiel: Reverse of the rear naked choke, using the inside of the sleeves for grip. Guillotine choke: a facing choke, usually applied to an opponent from above. Gearlock: a modified sleeper hold that puts an incredible amount of force on the opponents windpipe, choking them out almost instantly if applied properly.


NN 2 dinitrogen
Nitrogen can be used as a replacement, or in combination with, carbon dioxide to pressurise kegs of some beers, particularly stouts and British ales, due to the smaller bubbles it produces, which makes the dispensed beer smoother and headier. A pressure-sensitive nitrogen capsule known commonly as a "widget" allows nitrogen-charged beers to be packaged in cans and bottles. Nitrogen tanks are also replacing carbon dioxide as the main power source for paintball guns. Nitrogen must be kept at higher pressure than CO 2, making N 2 tanks heavier and more expensive.

Triangle choke

Sankaku-jimesankaku jimetriangles
A triangle choke, or sankaku-jime in judo, is a type of figure-four chokehold that strangles the opponent by encircling the opponent's neck and one arm with the legs in a configuration similar to the shape of a triangle. The technique is a type of lateral vascular restraint that constricts the blood flow from the carotid arteries to the brain. The triangle choke was seen in early kosen judo competition. While details of its origin are unknown, it is strongly associated to Yaichibei Kanemitsu and his apprentice Masaru Hayakawa, who featured the first registered use of the move in a kosen judo tournament in Kobe, Hyogo in November 1921.

Hypoxia (medical)

Such situations may lead to unconsciousness without symptoms since carbon dioxide levels are normal and the human body senses pure hypoxia poorly. Inert gas asphyxiation may be deliberate with use of a suicide bag. Accidental death has occurred in cases where concentrations of nitrogen in controlled atmospheres, or methane in mines, has not been detected or appreciated. Hemoglobin's function can also be lost by chemically oxidizing its iron atom to its ferric form. This form of inactive hemoglobin is called methemoglobin and can be made by ingesting sodium nitrite as well as certain drugs and other chemicals.


Whitehaven, EnglandHaig Pit, WhitehavenWellington Colliery, Whitehaven
To counter the considerable danger of methane gas explosion, Carlisle Spedding invented a forerunner to the 'Safety Lamp', known as the Spedding Wheel or Steel Mill. This used the sparks generated by a flint against a rotating steel wheel to provide light, on the basis the sparks were not quite hot enough to ignite the gas. On occasions it caused explosions or fires but it was a major improvement over the naked flame. Lowther also supported experimental work on firedamp by William Brownrigg, a local doctor and scientist, and he presented papers by Brownrigg at the Royal Society.


veinsvenousvenous system
After taking up cellular waste and carbon dioxide in capillaries, blood is channeled through vessels that converge with one another to form venules, which continue to converge and form the larger veins. The de-oxygenated blood is taken by veins to the right atrium of the heart, which transfers the blood to the right ventricle, where it is then pumped through the pulmonary arteries to the lungs. In pulmonary circulation the pulmonary veins return oxygenated blood from the lungs to the left atrium, which empties into the left ventricle, completing the cycle of blood circulation.


Carbon dioxide occupies a different binding site on the hemoglobin. Carbon dioxide is more readily dissolved in deoxygenated blood, facilitating its removal from the body after the oxygen has been released to tissues undergoing metabolism. This increased affinity for carbon dioxide by the venous blood is known as the Haldane effect. Through the enzyme carbonic anhydrase, carbon dioxide reacts with water to give carbonic acid, which decomposes into bicarbonate and protons: Hence, blood with high carbon dioxide levels is also lower in pH (more acidic). Hemoglobin can bind protons and carbon dioxide, which causes a conformational change in the protein and facilitates the release of oxygen.

Sir James Lowther, 4th Baronet

James LowtherSir James LowtherJames
Spedding improved this by ensuring that after ventilating areas currently being worked the exhaust stream was routed through previously worked areas to eliminate any possibility of firedamp accumulation in unventilated volumes. This practice also spread from the Lowther pits to become standard practice in other coalfields. Lowther also supported experimental work on firedamp by William Brownrigg, a local doctor (and a son of the local gentry; in due course he married a Spedding daughter) and presented papers by Brownrigg at the Royal Society.


hazardous volcanic gases
In geology, a mazuku (Swahili: evil wind) is a pocket of carbon dioxide-rich air that can be lethal to any human or animal life inside. Mazuku are created when carbon dioxide accumulates in pockets low to the ground. CO 2 is heavier than air, which causes it to flow downhill, hugging the ground like a low fog, and is also undetectable by human olfactory or visual senses in most conditions. Mazuku can be related to volcanic activity or to a natural disaster known as a limnic eruption. In the first case, noxious gases are released from the Earth's crust into the atmosphere, whereas in the second case the gases originate deep in a lake and boil rapidly to the surface.

J. B. S. Haldane

J.B.S. HaldaneHaldaneJohn Burdon Sanderson Haldane
Haldane was born in Oxford to John Scott Haldane, a physiologist, scientist, a philosopher and a Liberal, and Louisa Kathleen Trotter, a Conservative. His younger sister, Naomi Mitchison, became a writer, and his uncle was Viscount Haldane and his aunt the author Elizabeth Haldane. Descended from an aristocratic and secular family of the Clan Haldane, he would later claim that his Y chromosome could be traced back to Robert the Bruce. He grew up at 11 Crick Road, North Oxford. He learnt to read at the age of three, and at four, after injuring his forehead he asked the doctor, "Is this oxyhaemoglobin or carboxyhaemoglobin?".

University of Edinburgh

Edinburgh UniversityEdinburghThe University of Edinburgh
(James Young Simpson) and SARS (Nanshan Zhong); and the inventing of the telephone (Alexander Graham Bell), the hypodermic syringe (Alexander Wood), the kaleidoscope (David Brewster), the telpherage (Fleeming Jenkin), the vacuum flask (James Dewar), the ATM (John Shepherd-Barron) and the diving chamber (John Scott Haldane).

Coalbed methane

coal seam gascoal bed methanecoal-bed methane
If the gas contains more than a few percent non-flammable gases such as nitrogen or carbon dioxide, either these will have to be removed or it will have to be blended with higher-BTU gas to achieve pipeline quality. If the methane composition of the coalbed gas is less than 92%, it may not be commercially marketable. As with all carbon based fossil fuels, burning coalbed methane releases carbon dioxide (CO 2 ) into the atmosphere. Its effect as greenhouse gas was firstly analyzed by chemist and physicist Svante Arrhenius. CBM production also entails leaks of fugitive methane into the atmosphere.


Choke-outs should not be confused with erotic asphyxiation or the fainting game, wherein a person loses consciousness intentionally in order to experience a particular sensation. A choke-out should also not be confused with medical conditions that cause fainting without the application of a chokehold. Chokeholds can be divided into two primary categories: "blood chokes" and "air chokes". A blood choke disrupts blood circulation to the brain, while an air choke disrupts breathing.

Gresford disaster

A major explosiongas explosionGresford
The divisional inspector, Charlton, countered the miners' theories by suggesting that firedamp had actually accumulated further up the Dennis main road just beyond the Clutch. This gas was ignited at the Clutch when a telephone was used to warn miners of the influx of firedamp. Shawcross suggested that the explosion might have been caused by the spontaneous heating of a pillar of coal, based on reports of a burning smell in the area of the Clutch prior to the disaster.