The Mystery of "Ghost Fire"

Yin fire is the common name of phosphorus fire, also known as ghost fire, the flame when phosphine burns. Phosphorus reacts with water or alkali to form phosphine, which is a colorless gas and can spontaneously ignite. Phosphine is released when human and animal carcasses decompose and spontaneously ignite. The white blue-green flame sometimes seen in the wild at night is phosphorus fire.

The temperature of yin fire is not high, the ignition point of phosphine is very low, and it will burn when exposed to air at room temperature. After phosphine is produced, it is emitted into the air along cracks or holes in the ground, and emits blue light after burning.

On summer nights, blue-green flames sometimes appear in the suburbs or near ancient tombs, looming and erratic. There used to be a legend in the countryside that people would become ghosts after death. Ghosts are afraid of light and dare not come out during the day, but only appear at night. In the cemetery or wilderness, sometimes there will be green or light blue flame clouds at night, jumping infinitely. What's even weirder is that it will follow people, stop when you stop, and follow you when you run. Superstitious people say that this is a kind of "ghost fire" for ghosts to go out at night, and they also describe it as a ghost lamp in Yan Luowang. In Strange Tales from a Lonely Studio by Pu Songling, a writer in Qing Dynasty, people often talk about it.

In fact, this is caused by phosphorus. It turns out that both human and animal bodies (animal bones in rural areas and human bones in graves after death) contain phosphorus, which is neither white phosphorus nor red phosphorus, but exists in the form of phosphorus compounds. People and animals are buried underground after death, and their bodies rot. After long-term scorching sun and rain and dew leaching, phosphorus compounds gradually penetrate into the soil and decompose to form phosphine. There are many kinds of phosphine gas, one of which is called "bisphosphite", which, like white phosphorus, will spontaneously ignite in the air. This gas leaks from the ground and comes into contact with oxygen in the air. Due to the high temperature in summer, it is easy to reach the ignition point of phosphine gas and spontaneously ignite, resulting in a weak blue-green flame and a "ghost fire". In fact, phosphine will come out no matter day or night, but the sun is very strong during the day and you can't see the "jack-o'-lantern". This is why "ghost fires" can often be seen in cemeteries on summer nights.

Then why does "Jack-o 'lantern" chase people everywhere? As we all know, at night, especially when there is no wind, the air is generally still. Because the phosphorus fire is very light, if the wind or people pass by and drive the air to flow, the phosphorus fire will float with the air, even with the pace of people, it will be slow if you are slow, and it will be fast if you are fast; When you stop, because there is no power to drive the air, the air stops, and the "ghost fire" naturally stops. This phenomenon is by no means a ghost chasing people.

As a matter of fact, the saying of jack-o'-lantern is not unique to China. Phosphorus was discovered in 1669 by Brandt, an alchemist in Hamburg, Germany. The Greek original meaning of "phosphorus" is "ghost fire".

phosphine

Phosphine; Phosphine; Phosphine; Phosphine; Phosphine; Phosphorus trihydroxide; CASNo.: 7803-5 1-2

physicochemical property

Colorless gas. It has almost no taste when it is pure, but industrial products smell like rotten fish. The molecular formula is H3-p and the molecular weight is 34. The relative density is 1. 17. Melting point-133℃. Boiling point -87.7℃. Autoignition point 100 ~ 150℃. The vapor pressure is 20 atmospheres (-3℃). The lower explosive limit of air mixture is 1.79%(26 g/m3. Slightly soluble in water (0.26 volume phosphine can be dissolved at 20℃). Trace P2H4 in the air can spontaneously ignite; When the concentration reaches a certain level, an explosion may occur. It can react violently with oxygen and halogen. Phosphate is formed by hot metal blocks and hydrogen is released. It can also react with copper, silver, gold and their salts.

Contact opportunity

In industry, phosphine can be produced when water acts on calcium phosphide, or hydrogen acts on yellow phosphorus, or yellow phosphorus is boiled with alkali. Phosphorus refining and phosphide manufacturing, acetylene manufacturing, ferrosilicon containing phosphide can produce phosphine when it meets water. It can be used as animal feed and fumigant for tobacco; Dopant of n-type semiconductor; Polymerization initiator; Condensation reaction catalyst; It can also be used as an intermediate for the production of several flame retardants. Phosphine may be exposed in the above process.

Invasive pathway

Absorbed through the respiratory tract. Oral zinc phosphide enters the stomach, releases PH3 when it meets gastric acid, and sucks blood from the gastrointestinal tract.

Introduction to toxicology

People inhale LCL0: 1000 ppm/5M. Rats inhaled LC50: 1 1 ppm/4H. Mice inhaled LCL 0: 380mg/m3 /2H. Highly toxic. Toxic effect on human beings: when the concentration in the air is 2 ~ 4 mg/m3, the odor can be smelled; Concentration higher than 9.7 mg/m3 can cause poisoning; Exposure of 550 ~ 830mg/m3 to 0.5 ~1.0 hours, 2798mg/m3 can cause rapid death. The oral LD 100 of zinc phosphide is about 40mg/kg. After phosphine is inhaled from the respiratory tract, it first stimulates the respiratory tract, causing mucosal congestion and edema, alveolar congestion and exudation, and severe cases of massive bleeding, and the alveoli are full of bloody exudates, which is the pathological basis of acute pulmonary edema. Phosphine is absorbed into the whole body by alveoli, affecting the central nervous system, heart, liver, kidney and other organs. Mistaken phosphate releases phosphine in the stomach when it meets acid in the mouth, and is absorbed into the blood from the gastrointestinal tract, which is similar to poisoning caused by inhaling phosphine from the respiratory tract.

The metabolism of phosphine in the body is not clear.

clinical picture

Acute phosphine poisoning is a systemic disease caused by inhaling phosphine gas (or taking zinc phosphide by mistake), which mainly damages the nervous system and respiratory system.

Acute phosphine poisoning starts quickly, and severe poisoning symptoms can appear in a few minutes, but the incubation period of individual patients can reach 48 hours. Acute phosphine poisoning is mainly manifested as dizziness, headache, fatigue, nausea, vomiting, loss of appetite, cough, chest tightness, dry throat, abdominal pain and diarrhea. Electrocardiogram showed ST-T changes or abnormal liver function, and most of them recovered within 1 week after proper treatment. In addition to the above clinical manifestations, severe poisoning may have one or more of the following manifestations: coma, convulsion, pulmonary edema, shock, obvious myocardial damage and obvious liver and kidney damage. The main dangerous period is within 1 ~ 3 days after onset. If you can survive 1 week, you can recover, and generally there will be no sequelae.

Respiratory and nervous system symptoms appear faster after phosphine inhalation, and gastrointestinal symptoms appear earlier and more prominent after zinc phosphide oral poisoning.

Acute phosphine poisoning can be diagnosed according to contact history or poisoning history, clinical examination, reference to on-site labor hygiene investigation and exclusion of other diseases with similar symptoms. The determination of blood phosphorus and blood calcium has no diagnostic significance.

deal with

Leave the scene immediately and deal with it according to the general first aid routine. Those who take zinc phosphide orally should actively induce vomiting, gastric lavage and catharsis to eliminate the residual toxins in the gastrointestinal tract. Even if the drug treatment has been delayed for a long time, gastric lavage should still be actively carried out. Patients with symptoms should be observed for at least 24 ~ 48 hours, so as to find out the changes of the disease at an early stage. Protect the function of important organs and give adequate nutrition and vitamins. There is no specific antidote, so oxime drugs cannot be used. Treatment is mainly symptomatic and supportive therapy. Coma, pulmonary edema, liver and kidney damage should be treated actively as soon as possible, and its treatment principles and nursing care are similar to those of internal medicine.